tag:blogger.com,1999:blog-33645708340991312012024-03-28T15:15:10.231-04:00ECG InterpretationEKG Interpretation Reviews<br><a href="http://www.kg-ekgpress.com" title="ecg interpretation books">KG-EKGPress.com - ECG, ACLS, Arrhythmia books & ePubs - by KEN GRAUER, MD</a>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.comBlogger428125tag:blogger.com,1999:blog-3364570834099131201.post-75466894667705994572024-03-27T18:57:00.003-04:002024-03-27T19:01:51.304-04:00ECG Blog #422 — Was Clubbing an ECG Hint?<span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;">I was sent the ECG in <u style="font-weight: bold;">Figure-1</u> — with the following history:</div><div style="text-align: justify;"><ul><li>The patient is a young man in his early 20s — who presents to the ED (<i><u>E</u>mergency <u>D</u>epartment</i>) because of SOB (<i><u>S</u>hortness <u>O</u>f <u>B</u>reath</i>) that had been ongoing for several hours. <i>No chest pain</i>.</li><li>He reports a number of similar previous episodes over the past few years (<i>although apparently has not been formerly evaluated for this</i>).</li><li>Physical exam remarkable for tachypnea (<i>respiratory rate ~30/minute</i>) and cyanosis, with clubbing of extremities.</li></ul></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>QUESTIONS:</u></b></div><div style="text-align: justify;"><ul><li>In view of the above history — <i>How would YOU interpret</i> the ECG in <u>Figure-1</u>?</li><li>Is the rhythm <b><i>likely to be</i> VT (</b><i><u>V</u>entricular <u>T</u>achycardia</i><b>)?</b></li></ul></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg104R45zZEiki-iPWq9HeaTp2JD7EfxFiY6eftAZSQB_jmUhdbsZLJ5FtMutYWjKiNvbHLmu58NhE54g1hDIyB1wyLLjO3BDnrS4fQxPS9uCNmkIbEddbdxT-7zJXqF_qwb8IJWKzAg-GvlJP7Frnxm08O4oCsmbBD02ds0t55qiUxkyMKXkiXXShCuJs/s3776/Figure-1%20%20ECG-1%20(3-16.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1486" data-original-width="3776" height="158" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg104R45zZEiki-iPWq9HeaTp2JD7EfxFiY6eftAZSQB_jmUhdbsZLJ5FtMutYWjKiNvbHLmu58NhE54g1hDIyB1wyLLjO3BDnrS4fQxPS9uCNmkIbEddbdxT-7zJXqF_qwb8IJWKzAg-GvlJP7Frnxm08O4oCsmbBD02ds0t55qiUxkyMKXkiXXShCuJs/w400-h158/Figure-1%20%20ECG-1%20(3-16.21-2024)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-1:</u></b><span style="text-align: justify;"> The <b><u style="font-style: italic;">initial</u> ECG</b> in today’s case.</span></span></td></tr></tbody></table><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u><br /></u></b></div><div style="text-align: justify;"><b><u>MY <i>Initial</i> Thoughts on Figure-1:</u></b></div><div style="text-align: justify;">Although technically there is some folding and distortion of this 12-lead tracing — the recording speed is the standard <b>25 mm/second</b> — and quality of the tracing clearly <i><u>is</u></i> sufficient for evaluation.</div><div style="text-align: justify;"><ul><li>There is a <b><i>regular </i>WCT (</b><i><u>W</u>ide-<u>C</u>omplex <u>T</u>achycardia</i><b>)</b> in <u>Figure-1</u> — at a rate of <b>~190/minute</b>, but <b><i><u>without</u></i> clear sign of sinus P waves</b>.</li><li>I thought that some kind of atrial activity <i>might</i> be present — but I was <i><u>not</u></i> certain of this. Despite the presence of a slender upright deflection before each P wave in lead I — there was <u style="font-style: italic;">no</u> such upright deflection in lead II (<i>as is <u>needed</u> for the rhythm to be sinus</i>).</li><li>I considered the possibility of 1:1 retrograde P waves (<i>VA conduction</i>) — but I did <i><u>not</u></i> know if the slender negative “dip” in the middle of the inferior lead ST-T waves represented a retrograde P wave <u style="font-style: italic;">vs</u> simply being the ST segment alone.</li><li><br /></li><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>1:</u> Even if this negative “dip” in the inferior lead ST segments did represent retrograde P waves — this would <u style="font-style: italic;">not</u> be of any assistance for distinguishing between some form of SVT (<i><u>S</u>upra<u>V</u>entricular <u>T</u>achycardia</i>) <u>vs</u> VT — because reentry SVT rhythms <u>and</u> VT may <i><u>both</u></i> manifest 1:1 VA retrograde conduction.</li><li><br /></li><li><b><u>MY Conclusion <i>Thus</i> Far:</u> </b>The rhythm in <u>Figure-1</u> represents a <b><i>regular</i></b> <b>WCT</b> rhythm at ~190/minute, without clear sign of sinus P waves. This leaves us with the usual differential diagnosis for this rhythm presentation <b>(</b><i>as per </i><b><a href="https://ecg-interpretation.blogspot.com/2023/02/ecg-blog-361-another-wct-rhythm.html" target="_blank">ECG Blog #361</a>) </b>==><b> </b><i>We need to consider</i><b> i<span style="color: red;">)</span> </b>VT <i><u>until</u></i> proven otherwise: <b>ii<span style="color: red;">)</span> </b>SVT with <i><u>either</u></i> preexisting BBB <u>or</u> aberrant conduction; — <u>or</u>, <b>iii<span style="color: red;">)</span></b><i><b> </b>Something </i>else <b>(</b>ie, <i>WPW, hyperkalemia, some other toxicity, etc.</i><b>)</b>.</li></ul><div><br /></div><div><br /></div><div><b><u>PEARL <span style="color: red;">#</span>2:</u> How <i>Might</i> the <i><u>History</u></i> Help?</b></div><div>Statistically — When an older adult with known underlying heart disease presents to the ED in a <i>regular</i> WCT rhythm, but <i>without</i> clear sign of sinus P waves — the odds that the rhythm will turn out to be VT are ~90% even <u style="font-style: italic;">before</u> you look at the ECG. But this is <u style="font-style: italic;">not</u> the situation in today's case — since today's patient is a man in his early 20s.</div><ul><li>Although this young adult age range places today's patient in the group most susceptible to some form of <b><i>idiopathic</i></b> <b>VT (</b><i>See</i> <b><a href="https://ecg-interpretation.blogspot.com/2021/02/blog-197-ecg-mp-14-svt-with-aberrancy.html" target="_blank">ECG Blog 197</a>)</b> — Strongly <i><u>against</u></i> a diagnosis of <i>idiopathic</i> VT are the physical findings of <b><i>cyanosis</i></b> and <b><i>clubbing</i></b> of the extremities, since these findings strongly suggest some form of underlying cardiopulmonary disease.</li></ul><div><br /></div><div><br /></div><div><b><u>PEARL <span style="color: red;">#</span>3:</u> <i>What about </i><u>QRS</u> <u>Morphology</u>?</b></div><div>As discussed in detail in many of my blog posts that break down the assessment of regular WCT rhythms — QRS morphology may provide invaluable assistance for working through the differential diagnosis <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2012/05/ecg-interpretation-review-42-vt-brugada.html" target="_blank">ECG Blog #42</a></b><i>, among many others</i><b>)</b>.</div><ul><li>Although no morphologic criterion is perfect for distinguishing between supraventricular conduction <u style="font-style: italic;">vs</u> VT — the more QRS morphology of a <i>regular</i> WCT rhythm resembles some known form of conduction defect, the greater the chance that the rhythm is of supraventricular etiology. </li><li>Conversely — the more <i>abnormal-looking</i> QRS morphology during a regular WCT rhythm is <b>(</b>ie, <i>the less it resembles some known form of conduction block</i><b>)</b> — the greater the chance that the rhythm represents an ischemic form of VT.</li></ul><div><br /></div><div>Today's case therefore presents the paradox that <i><u>despite</u></i> this patient's young age — <b><i>QRS morphology of his ECG manifests many atypical features</i></b>. These include: <b>i<span style="color: red;">)</span></b> Significant <b>fragmentation (</b>ie, <i>multiple leads in <u>Figure-1</u> showing multiple "extra notching" of the QRS complex</i><b>)</b>; <u>and</u>, <b>ii<span style="color: red;">)</span></b> <b>Bizarre shape of the QRS complex</b> in <b>lead V1</b>, with a rounded R' deflection instead of a more defined triphasic rsR' configuration <b>(</b><i>as is most often seen with RBBB-conduction in a younger adult</i><b>)</b>.</div><div><ul><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>4:</u> The combination of longstanding dyspnea episodes in this young adult with cyanosis and extremity clubbing <b>+</b> the above described atypical QRS morphology during his WCT — should suggest some form of significant underlying cardiopulmonary disease. High on my list of possibilities was an <b><i>expression of</i></b> <b>CHD (</b><i><u>C</u>ongenital <u>H</u>eart <u>D</u>isease</i><b>)</b> <b><i>in an </i>adult</b>.</li><li><br /></li><li>This still leaves us with the differential diagnosis for the <b><i>regular</i></b> <b>WCT rhythm</b> in today’s case between a <b><i><u>fascicular</u></i></b> <b>VT (</b><i>given some resemblance to rbbb conduction in the chest leads — with marked right axis deviation in the limb leads</i><b>)</b> — <u>vs</u> <i>some</i> form of an <b>SVT</b> rhythm, in which the patient’s baseline tracing was rendered markedly abnormal from longstanding CHD.</li><li><u style="font-weight: bold;"><i>MY </i>Hunch:</u> Awareness of the longstanding nature of today’s patient’s symptoms from some presumed form of established CHD — made me suspect that a <b><i><u>supraventricular</u></i></b> <b>etiology</b> would be more likely, rather than sudden development of fascicular VT. That said, I could <u style="font-style: italic;">not</u> rule out the possibility of fascicular VT on the basis of this single tracing.</li><li><br /></li><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>5:</u> Finding a copy of a <b><i><u>prior</u></i></b> <b>ECG</b> on today's patient could be the most <i>time-efficient</i> way to determine IF the <i>regular</i> WCT rhythm in <u>Figure-1</u> was of a supraventricular etiology, as I suspected. If this were the case — the patient's baseline ECG during sinus rhythm would most likely manifest a very abnormal QRS morphology <b>(</b><i>similar to that seen in </i><u>Figure-1</u><b>) </b>—<b> </b>as the result of longterm hypoxemia. </li></ul></div></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;">==========================</div><div style="text-align: justify;"><b><u><i>Today’s</i> <span style="color: red;">C</span>ASE <span style="color: red;">C</span>ontinues</u></b>:</div><div style="text-align: justify;">Medical treatment of the WCT rhythm shown in <u>Figure-1</u> — was not successful. As a result, <b><i>synchronized </i>cardioversion </b>was performed — after which the <b><i><u>post</u>-cardioversion</i> rhythm</b> shown at the bottom of <u style="font-weight: bold;">Figure-2</u> was obtained.</div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>QUESTIONS:</u></b></div><div style="text-align: justify;"><ul><li><i>How would you interpret</i> this <i><u>post</u>-cardioversion</i> tracing?</li><li>Why does QRS morphology in <u>ECG #2</u> change every-other-beat? <i><b>How does this changing QRS morphology </b>in ECG #2<b> </b><u style="font-weight: bold;">confirm</u><b> that </b>the rhythm in </i><u style="font-weight: bold;">ECG #1</u><b> is </b><u style="font-style: italic; font-weight: bold;">not</u><b> VT?</b></li></ul></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsRRdygyN3tn5SuLOmwlJ4xHIbyelVvVSwS9LLlyUm48NdRcjRv_NBNQpQzEXYCNy9duEDOOgxdPPTh5Int6zXGE5OSGbNHYgORDN2bo9nZzyymPorEVU3CZa7aD2SHPLIj0vl_ToBQnqYbgBtdb1eT9nwDaswR8tpILEatn2DV4haieADr-_PciFXhRk/s3684/Figure-2%20%20ECGs-1,2%20(3-16.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2822" data-original-width="3684" height="306" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsRRdygyN3tn5SuLOmwlJ4xHIbyelVvVSwS9LLlyUm48NdRcjRv_NBNQpQzEXYCNy9duEDOOgxdPPTh5Int6zXGE5OSGbNHYgORDN2bo9nZzyymPorEVU3CZa7aD2SHPLIj0vl_ToBQnqYbgBtdb1eT9nwDaswR8tpILEatn2DV4haieADr-_PciFXhRk/w400-h306/Figure-2%20%20ECGs-1,2%20(3-16.21-2024)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-2:</u></b><span style="text-align: justify;"> Comparison between today’s <b><u style="font-style: italic;">initial</u> ECG</b> — with the <b><u style="font-style: italic;">repeat</u> ECG </b>obtained following synchronized cardioversion (<i>See text</i>).</span></span></td></tr></tbody></table><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>The <i><span style="color: red;">P</span>ost-<span style="color: red;">C</span>onversion</i> <span style="color: red;">T</span>racing in Figure-2:</u></b></div><div style="text-align: justify;"><b><i>Sinus</i></b> <b>rhythm</b> has been restored in the post-cardioversion tracing, at a rate of <b>~100/minute</b> — as determined by the presence of <b>huge</b>, <b><i>upright</i></b> and <b><i>pointed</i></b> <b>P waves</b> with a constant and normal PR interval in front of each of the 17 beats in the long lead II rhythm strip.</div><div style="text-align: justify;"><ul><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>6:</u> The fact that sinus P waves with the <u style="font-style: italic;">identical</u> PR interval are seen in front of <i>each</i> beat in <u><b>ECG #2</b></u> — confirms that the post-cardioversion rhythm is of <b><u style="font-style: italic;">sinus</u> origin</b>. This means that the <i>changing</i> QRS morphology every-other-beat <i>must be</i> the result of some <i>alternating</i> form of conduction defect.</li><li><u style="font-weight: bold;">NOTE:</u> This changing QRS morphology in <u>ECG #2</u> is more evident in some leads than in others <b>(</b>ie, <i>While <u>not</u> so evident in lateral chest leads V4,5,6 of ECG #2 — the alternating QRS morphology <u>is</u> obvious in leads such as I, III, aVL, V1 and V3</i><b>)</b>.</li></ul><div><br /></div><div><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>7:</u> As unusual as QRS morphology is <i>during</i> the regular WCT rhythm in today's <b><i><u>initial</u></i></b> <b>ECG</b> — Compare this QRS morphology <b>(</b><i>within the dark BLUE rectangles in </i><u style="font-weight: bold;">Figure-3</u><span style="font-weight: bold;">)</span> — to QRS morphology of <i>odd-numbered </i>beats in each of the 12-leads of the post-cardioversion tracing <b>(</b><i>within the light BLUE rectangles in Figure-3</i><b>)</b>.</div><div><ul><li>With the exception of minor differences — <i>Isn't QRS morphology <u>during</u> the WCT — </i>and, for <i>odd-numbered </i>beats <u style="font-style: italic;">after</u> conversion to sinus rhythm, <i>virtually the same?</i></li><li><br /></li><li><b><u><i>KEY</i> Point:</u></b> This <i>virtually-the-same</i> QRS morphology during and after confirms that the regular WCT in today's initial tracing was <u style="font-style: italic;">not</u> VT. Instead, it tells us that today's patient has an extremely abnormal "baseline" ECG.</li></ul></div><div><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkp1MfTqrLxN83qPHtDOx0b3d5DawrYNVjBAlPqNXZEtB0IRH-c4Pe60rSDG3B8zL0GYwoMoa5WbMTZfwFaTnl9R51iTkDzOXhoqAI7e16-0QcyW7kPL0_FM-2znpg99XBBLVYoC5K2kGgO3X0JRHEa0W42RvLm8ElU5Vfc9cabv-p2dBFC-wXUJ74Nfw/s3450/Figure-3%20%20ECGs-1,2%20(3-27.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2692" data-original-width="3450" height="313" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkp1MfTqrLxN83qPHtDOx0b3d5DawrYNVjBAlPqNXZEtB0IRH-c4Pe60rSDG3B8zL0GYwoMoa5WbMTZfwFaTnl9R51iTkDzOXhoqAI7e16-0QcyW7kPL0_FM-2znpg99XBBLVYoC5K2kGgO3X0JRHEa0W42RvLm8ElU5Vfc9cabv-p2dBFC-wXUJ74Nfw/w400-h313/Figure-3%20%20ECGs-1,2%20(3-27.1-2024)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-3:</u></b><span style="text-align: justify;"> Comparison of QRS morphology <u style="font-style: italic;">during</u> the WCT — and for <i>odd-numbered</i> beats <u style="font-style: italic;">after</u> conversion to sinus rhythm (<i>See text</i>).</span></span></td></tr></tbody></table><br /><div><br /></div><div><b><u><i>What Kind</i> of <i>Conduction</i> Defect?</u></b></div><div>As is often emphasized on this ECG Blog <b>(</b>ie, <i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-204-ecg-mp-22-bundle-branch.html" target="_blank">ECG Blog #204</a>)</b> — Rapid determination of the type of conduction defect is most easily <b>(</b><i>and most time-efficiently</i><b>)</b> determined by assessment of QRS morphology in <b>3 <i>KEY</i> leads (</b> = <i>right-sided</i> <b>lead V1</b> <i>— and left-sided</i> <b>leads I</b> <i>and</i> <b>V6)</b>.</div><div><ul><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>8:</u> QRS morphology of <i><u>odd</u>-numbered</i> beats in the post-cardioversion tracing <b>(</b>ie, <i><u>within</u> the light BLUE rectangles of </i><u style="font-weight: bold;">ECG #2</u> <i>in </i><b><u>Figure-4</u>) </b>— is consistent with <b>RBBB/LPHB conduction</b> because: <b>i<span style="color: red;">)</span> </b>There is an rSR' complex with taller right rabbit ear in lead V1 — with wide terminal S waves in lateral leads I and V6; <u>and</u>, <b>ii<span style="color: red;">)</span> </b>The S wave in lead I is predominantly negative, with an extremely deep straight component to this S wave <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-203-ecg-mp-2021-axis.html" target="_blank">ECG Blog #203</a> </b><i>for review on the rapid ECG diagnosis of the hemiblocks</i><b>)</b>.</li><li><br /></li><li><b><u><i>KEY</i> Point:</u></b> In contrast to the RBBB/LPHB conduction of <i>odd-numbered</i> beats in <u>ECG #2</u> — <i>even-numbered</i> beats in <u>Figure-4</u> show <i>neither</i> RBBB nor LPHB conduction! </li></ul></div></div><br /><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEipWmqUuu5HqrSoIz0YZCYaBFYIcekiMkY1MLUrIvb4OHOywF_rx5zdgTmI4fSrefEDuc5MTvJ-4eA64VEDdABO4KoWyX63VvWGRLVsi8O-2c4GJioXSlvX-d1TnNGgMRfGpMUJVqFDLbNv4jtvKFY8Au_FHYD4HnhZTHgN-bFBzPpicRkJ2nl0tBVvpfg/s3454/Figure-4%20%20ECGs-1,2%20(3-27.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2694" data-original-width="3454" height="313" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEipWmqUuu5HqrSoIz0YZCYaBFYIcekiMkY1MLUrIvb4OHOywF_rx5zdgTmI4fSrefEDuc5MTvJ-4eA64VEDdABO4KoWyX63VvWGRLVsi8O-2c4GJioXSlvX-d1TnNGgMRfGpMUJVqFDLbNv4jtvKFY8Au_FHYD4HnhZTHgN-bFBzPpicRkJ2nl0tBVvpfg/w400-h313/Figure-4%20%20ECGs-1,2%20(3-27.1-2024)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-4:</u></b><span style="text-align: justify;"> I've labeled <i>KEY</i> findings in today's case.</span></span></td></tr></tbody></table><div style="text-align: justify;"><div><i><br /></i></div><div>==========================</div><div><b><i><u><span style="color: red;">P</span>utting <span style="color: red;">I</span>t <span style="color: red;">A</span>ll <span style="color: red;">T</span>ogether:</u></i></b></div><div>We finally have enough information to explain today's fascinating case:</div><div><ul><li>This young man in his early 20s presented with an episode of acute dyspnea in a <b><i>regular</i> WCT rhythm</b> at ~190/minute, <i>without</i> clear sign of sinus P waves.</li><li><b>Definitive ECG diagnosis was <i><u>not</u></i> possible on the basis of the single tracing shown in <u>ECG #1</u></b>. That said — physical exam findings of cyanosis and clubbing, together with the history of longstanding dyspnea episodes suggested more of a chronic problem <b>(</b><i>presmably the expression of Congenital Heart Disease in an adult</i><b>)</b> — rather than an isolated episode of VT in a young man.</li><li>In any event — <b>the rhythm in <u>ECG #1</u> mandated treatment <u style="font-style: italic;">before</u> a definite ECG diagnosis was known</b>. When a trial of medical therapy was unsuccessful — synchronized cardioversion was performed — with resultant conversion to sinus rhythm <b>(</b><i>as shown in </i><b><u>ECG #2</u>)</b>.</li><li><br /></li><li>Proof that the unusual QRS morphology during the WCT rhythm was supraventricular — was forthcoming from the finding of nearly identical QRS morphology <i><u>during</u></i> the WCT rhythm — with QRS morphology of each <i>odd-numbered</i> beat <i><u>after</u></i> conversion to sinus rhythm.</li><li>This suggests that the reason for QRS widening during the initial ECG — was <b><u style="font-style: italic;">rate</u><span style="font-style: italic;">-related</span> <i><u>aberrant</u></i> conduction (</b><i>with a pattern of RBBB/LPHB conduction</i><b>)</b>. After conversion to sinus rhythm in <u>ECG #2</u> — the slower ventricular rate allowed for normal conduction with each <i>even-numbered</i> beat.</li><li><br /></li><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>9:</u> That today's patient almost certainly has some form of severe CHD as the cause of his longstanding dyspnea episodes, cyanosis and clubbing — is evident from the exceedingly tall, peaked and <b><i>pointed</i></b> <b>P waves</b> <b>(</b><i>nearly 1 large box tall in lead II — as well as being markedly peaked in many of the chest leads — as seen within the RED ovals in </i><u>ECG #2</u><b>)</b>. In the context of today's case — these P waves are diagnostic of <b>RAE =</b> <b>P Pulmonale (</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2013/09/ecg-interpretation-review-75-chamber.html" target="_blank">ECG Blog #75</a>)</b> and almost certain associated <b><i>pulmonary</i></b> <b>hypertension</b>.</li><li><br /></li><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>10:</u> <i>Taking another LOOK</i> at the <b><i><u>initial</u></i></b> <b>ECG</b> in today's case — atrial activity <i><u>was</u></i> evident during <u>ECG #1</u> <b>(</b><i>in the form of <b>retrograde P waves </b>with a relatively long RP' interval — as highighted by YELLOW arrows in Figure-4</i><b>)</b>. It is because of the <b><i>marked</i></b> <b>RAE (</b><i><u>R</u>ight <u>A</u>trial <u>E</u>nlargement</i><b>)</b> that when conducted retrograde, these huge P waves simulated inferior lead T wave inversion during the WCT rhythm. Retrospectively — I interpret this 1:1 retrograde conduction as diagnostic of a <b><u style="font-style: italic;">reentry</u> SVT rhythm</b> as the etiology of the initial tachycardia. Given the relatively long RP' interval — there is a good chance that this patient has an <b>AP (</b><i><u>A</u>ccessory <u>P</u>athway</i><b>)</b> — and that the type of SVT reentry is <b>AVRT (</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2021/07/ecg-blog-240-55-what-kind-of-regular-svt.html" target="_blank">ECG Blog #240</a></b><i> — for complete review on distinction between AVNRT vs AVRT depending on retrograde conduction features</i><b>)</b>.</li></ul></div></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u><i>FINAL</i> Thought:</u></b> The underlying etiology of today's tachyarrhythmia, and this patient's principal problem — appears to be the expression of CHD in an adult.</div><div style="text-align: justify;"><ul><li>As noted by Moodie in his manuscript on <b>Adult Congenital Heart Disease (<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3233326/" target="_blank">Tex Heart Inst J: 38(6):705, 2011</a>)</b> — there are now <i>more</i> people <i><u>over</u></i> the age of 20 with CHD than under that age!</li><li><br /></li><li>Hopefully today's patient receives full evaluation for his CHD. </li></ul></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div><span style="font-family: arial; font-size: medium;"><div><span style="color: #333333;"><span style="font-family: arial;">==================================</span></span></div><div><span style="font-family: arial;"><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Abdullah Al Mamum (<i>from Dhaka, Bangladesh</i>) for the case and this tracing.</span></div><div><span style="color: #333333;">==================================</span></div></span></div></span></div><div><br /></div><div><br /></div><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==============================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b>Additional<i> Relevant</i></b> <b>ECG Blog Posts to Today’s Case:</b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a> </b>— Reviews my System for <b><i>Rhythm</i></b> <b>Interpretation</b>, usin</span><span>g the </span><b><span style="color: red;">P</span>s, <span style="color: red;">Q</span>s & 3<span style="color: red;">R</span> Approach</b><span>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/04/blog-210-ecg-mp-27-regular-wct-how-fast.html " target="_blank">ECG Blog #210</a></b> — Reviews the <b>Every-Other-Beat (</b><i>or Every-Third-Beat</i><b>) Method</b> for estimation of <b><i>fast</i> heart rates</b> — and discusses another case of a <i>regular</i> WCT rhythm. </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-220-ecg-mp-37-vt-or-aberrancy.html" target="_blank">ECG Blog #220</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2023/02/ecg-blog-361-another-wct-rhythm.html" target="_blank">ECG Blog #361</a></b> — Review of the approach to the <b><i>regular</i></b> <b>WCT (</b> = <i><u>W</u>ide-<u>C</u>omplex <u>T</u>achycardia</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/blog-196-ecg-mp-13-is-this-vt-or-svt.html" target="_blank">ECG Blog #196</a></b> — Reviews another Case with a <b><i>regular</i></b> <b>WCT rhythm</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-263-13a-what-is-this-wct.html" target="_blank">ECG Blog #263</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2022/02/ecg-blog-283-vt-or-svt-with-aberrancy.html" target="_blank">Blog #283</a></b> — <i>More</i> <b>WCT Rhythms ...</b></span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/blog-197-ecg-mp-14-svt-with-aberrancy.html" target="_blank">ECG Blog #197</a></b> — Reviews the concept of <b><i>Idiopathic</i></b> <b>VT</b>, of which <b><i><u>Fascicular</u></i></b> <b>VT</b> is one of the 2 most common types. </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-346-recurrent-palpitations.html" target="_blank">ECG Blog #346</a></b> — Reviews a case of <b>LVOT VT (</b><i>a less common idiopathic form of VT</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-204-ecg-mp-22-bundle-branch.html" target="_blank">ECG Blog #204</a></b> — Reviews the ECG diagnosis of the <b>Bundle Branch Blocks (</b><i>RBBB/LBBB/IVCD</i><b>)</b>.</span><b> </b></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-203-ecg-mp-2021-axis.html " target="_blank">ECG Blog #203</a> </b>— Reviews ECG diagnosis of Axis and the <b>Hemiblocks</b>. For review of QRS morphology with the <b><i>Bifascicular</i></b> <b>Blocks (</b><i>RBBB/LAHB; RBBB/LPHB</i><b>)</b> — <i>See the </i><b><i><u>Video</u></i> Pearl</b> in this blog post.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/04/ecg-blog-211-ecg-mp-28-why-does.html" target="_blank">ECG Blog #211</a> </b>— <i>WHY</i> does <b><i>Aberrant</i></b> <b>Conduction</b> occur?</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2022/04/ecg-blog-301-40yo-man-vt-vs-aberrancy.html" target="_blank">ECG Blog #301</a></b> — Reviews a <b>WCT</b> that is <b><u>SupraVentricular</u>! (</b><i>with LOTS on Aberrant Conduction</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><br /></u></b></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2022/07/ecg-blog-323-wct-with-rbbb-morphology.html" target="_blank">ECG Blog #323</a></b> — Review of <b><i>Fascicular</i></b> <b>VT</b>. </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2012/02/ecg-interpretation-review-38-wct-svt-vt.html" target="_blank">ECG Blog #38</a></b> <u>and</u> <b><a href="https://ecg-interpretation.blogspot.com/2014/03/ecg-interpretation-review-85-aberration.html" target="_blank">Blog #85</a></b> — Review of <b><i>Fascicular</i></b> <b>VT</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://tinyurl.com/KG-Blog-278" target="_blank">ECG Blog #278</a></b> — Another case of a <b><i>regular</i></b> <b>WCT</b> rhythm in a younger adult.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2023/02/ecg-blog-361-another-wct-rhythm.html" target="_blank">ECG Blog #361</a></b> — A <b><i>regular</i></b> <b>WCT</b> in a middle-aged man.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2012/01/ecg-interpretation-review-35-sct-vt.html" target="_blank">ECG Blog #35</a></b> — Review of <b><i>RVOT</i></b> <b>VT</b>. </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2012/05/ecg-interpretation-review-42-vt-brugada.html" target="_blank">ECG Blog #42</a></b> — Review of <b><i><u>criteria</u></i></b> for distinguishing <b>VT</b> <u>vs</u> <b><i>aberrant</i></b> <b>conduction</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2016/12/ecg-blog-133-aberrant-conduction-vt.html" target="_blank">ECG Blog #133</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2018/04/ecg-blog-151-wct-vt-svt-av-dissociation.html" target="_blank">ECG Blog #151</a></b>— for examples in which <b>AV dissociation</b> <i><u>confirmed</u></i> the diagnosis of <b>VT</b>.</span></li></ul><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Working through a case of a <b><i>regular</i></b> <b>WCT</b> Rhythm in this 80-something woman — See <i>My Comment</i> in the <b><a href="http://hqmeded-ecg.blogspot.com/2020/05/is-it-vt-or-svt-with-aberrancy.html" target="_blank">May 5, 2020</a> post</b> on Dr. Smith’s ECG Blog. </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Another case of a <b><i>regular</i></b> <b>WCT</b> Rhythm in a 60-something woman — See <i>My Comment</i> at the bottom of the page in the <b><a href="https://hqmeded-ecg.blogspot.com/2020/04/60-something-with-wide-complex.html" target="_blank">April 15, 2020</a> post</b> on Dr. Smith’s ECG Blog. </span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Review of the <b><i>Idiopathic</i></b> <b>VTs (</b>ie, <i>Fascicular VT; RVOT and LVOT VT</i><b>)</b> — See <i>My Comment</i> at the bottom of the page in the <b><a href="http://hqmeded-ecg.blogspot.com/2020/09/young-man-with-heart-rate-of-257-what.html" target="_blank">September 7, 2020</a> post</b> on Dr. Smith’s ECG Blog.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Review of a <i>different</i> kind of VT (<b><i>Pleomorphic VT</i></b>) — See <i>My Comment</i> in the <b><a href="https://hqmeded-ecg.blogspot.com/2020/06/a-different-kind-of-wide-rhythm.html" target="_blank">June 1, 2020</a> post</b> on Dr. Smith’s ECG Blog. </span></li></ul><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjatWee2W48Bh23rkm3hVBpifsDfzqpN9-OjTIK4ekm14sEl2MRlkvCkOxtxMNVMFYAt07m0SNZmzaKDLeUpP0X8gXcl-Am4RJswxdfdywyAAFRHLkBvJu5KXkpl7ix9y9FKiUluxqsrY/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjatWee2W48Bh23rkm3hVBpifsDfzqpN9-OjTIK4ekm14sEl2MRlkvCkOxtxMNVMFYAt07m0SNZmzaKDLeUpP0X8gXcl-Am4RJswxdfdywyAAFRHLkBvJu5KXkpl7ix9y9FKiUluxqsrY/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div></div></div><div style="text-align: justify;"><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: center;"><br /></p><p></p><div><span style="text-align: left;"><div style="display: inline; text-align: justify;"><div><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"></div></div></div><div><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"> </p></div></div></div></span></div></div></div><div style="text-align: justify;"><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><br /></p></div><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"></span></div></div><div><br /></div><div><br /></div></div></span><div class="separator" style="clear: both; text-align: center;"><br /></div><br />ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-87161865287606663422024-03-16T00:45:00.000-04:002024-03-16T00:45:39.475-04:00ECG Blog #421 — Has there been a Recent MI?<div><span style="font-family: arial; font-size: medium;"><br /></span></div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;">What if you were asked to interpret the ECG in <u style="font-weight: bold;">Figure-1</u><span style="font-weight: bold;">?</span></div><div style="text-align: justify;"><ul><li><i>How would YOU interpret</i> the rhythm?</li><li>Even <u style="font-style: italic;">without</u> the benefit of any history — <i>Has there been a <u>recent</u> MI?</i></li></ul></div><div style="text-align: justify;"><br /></div></span><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAb6Z1UH4rQZBdlPQGqGCWJMFslk606XmvHVPce96DFmgBYZNLQIUUGTjYXrFKf4hgcVtt4M1Ag5ZWx5hOJxW_9nxNgHP4mczjmaI_L1_VjZrVK6PDNkeVuhAVy8kyB5EKBW4zyZKSS82lRijq7xuLJmIR2vD7ZxxjJSRdTNLGB4FazoLf1_-yD1lvUEo/s3776/Figure-1%20%20ECG-1%20PMcardio%20(2-18.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1658" data-original-width="3776" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAb6Z1UH4rQZBdlPQGqGCWJMFslk606XmvHVPce96DFmgBYZNLQIUUGTjYXrFKf4hgcVtt4M1Ag5ZWx5hOJxW_9nxNgHP4mczjmaI_L1_VjZrVK6PDNkeVuhAVy8kyB5EKBW4zyZKSS82lRijq7xuLJmIR2vD7ZxxjJSRdTNLGB4FazoLf1_-yD1lvUEo/w400-h176/Figure-1%20%20ECG-1%20PMcardio%20(2-18.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: start;"><u>Figure-1:</u></b><span style="text-align: start;"> </span></span><span style="font-family: arial; text-align: start;">The <b><i><u>initial</u></i></b> <b>ECG</b> in today's case.</span><span style="font-family: arial;"><span style="text-align: start;"> </span></span><b style="font-family: arial;">(</b><i style="font-family: arial;">To improve visualization — I've digitized the original ECG using</i><span style="font-family: arial;"> </span><b style="font-family: arial;"><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span style="font-family: arial;">.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;"><div><span style="font-family: arial; font-size: medium;"><b><u><i><br /></i></u></b></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><i>MY Approach </i>to Today’s Tracing:</u></b></span></div><div><span style="font-family: arial; font-size: medium;">As always — I favor beginning assessment with a quick look at the long lead rhythm strips at the bottom of the tracing. By the <b><u>P</u>s, <u>Q</u>s, 3<u>R</u> Approach (</b><i>which I review in </i><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a>):</b></span></div><div><ul><li><span style="font-family: arial; font-size: medium;">Lots of <b><u>P</u></b> waves are present — being well seen in the long lead II rhythm strip.</span></li><li><span style="font-family: arial; font-size: medium;">The <b><u>Q</u>RS</b> complex is narrow in all 12 leads.</span></li><li><span style="font-family: arial; font-size: medium;">The rhythm is <i><u>not</u></i> <b><u>R</u>egular</b>. The ventricular <b><u>R</u>ate</b> varies.</span></li><li><span style="font-family: arial; font-size: medium;">The 5th parameter of the Ps,Qs,3R Approach — is <b><i>the 3rd R</i></b>, which recalls <b>“<u>R</u>elated”</b> — or determining if P waves are (<i>or are not</i>) related to neighboring QRS complexes. This last parameter can best be assessed by labeling P waves in the long lead II rhythm strip.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u>QUESTIONS:</u></b></span></div><div><span style="font-family: arial; font-size: medium;"><i>Take a LOOK at</i> <u><b>Figure-2</b></u> — in which <i>RED arrows</i> highlight those <b>P waves</b> that are definitely seen on this tracing.</span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><i>How would YOU</i> describe the regularity (<i>or lack thereof</i>) of P waves in today's rhythm?</span></li><li><span style="font-family: arial; font-size: medium;">Are all of the P waves originating from the SA node?</span></li></ul></div></div></span></div><div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdrxYmysb9HcrrFlgEtdPl7LblHZkKV4x-pmNrwi1OTFW4MihTOq71PgJ7-7LxOXaswNlwr8pJzF5dVV4CTSpnW23GGHJ4TRGaIv4_nn-lNUhXNTMJZSCVVKKbgx1TfRerSijflqLlxs12TU4wwiqNYbMwSvjyM4g1kJWxGV3DDpz1YvxgCFd08bx477w/s3778/Figure-2%20%20ECG-1%20PMcardio-P%20waves%20(2-18.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1664" data-original-width="3778" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjdrxYmysb9HcrrFlgEtdPl7LblHZkKV4x-pmNrwi1OTFW4MihTOq71PgJ7-7LxOXaswNlwr8pJzF5dVV4CTSpnW23GGHJ4TRGaIv4_nn-lNUhXNTMJZSCVVKKbgx1TfRerSijflqLlxs12TU4wwiqNYbMwSvjyM4g1kJWxGV3DDpz1YvxgCFd08bx477w/w400-h176/Figure-2%20%20ECG-1%20PMcardio-P%20waves%20(2-18.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-2:</u></b><span style="text-align: start;"> I have labeled the P waves that we <i>definitely</i> see with <i>RED </i>arrows. <i>Is the underlying atrial rhythm <u>regular</u>?</i></span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>ANSWERS:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">We see in <u>Figure-2</u> — that each of the <i>RED arrow </i>P waves manifest a similar and normal P wave morphology — and, that each of these P waves are <u style="font-style: italic;">upright</u> in the long lead II rhythm strip. We can therefore presume these are <b>normal <u style="font-style: italic;">sinus</u> P waves</b>.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">With the exception of 2 places in the rhythm strip where we do not see P waves at the point where we might logically expect them — <i>Don’t the RED arrow P waves that we have labeled in <u>Figure-2</u> otherwise look fairly regular?</i></span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">NOTE:</u> If measured with calipers — We <i>know</i> that the <i>RED</i> arrow P waves in Figure-2 are <i><u>not</u></i> precisely regular. But what we are trying to determine, is if there is an underlying sinus mechanism. This includes <b><i><u>sinus</u></i></b> <b>arrhythmia</b> — in which there is often slight variation in the P-P interval. This slight variation in sinus P wave regularity tends to be greater when a 2nd- or 3rd-degree AV block is present <b>(</b><i>called </i><b style="font-style: italic;"><u>ventriculophasic</u></b> <b>sinus arrhythmia</b><i> — as shown in </i><b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-344-mobitz-i-mobitz-ii-or.html" target="_blank">ECG Blog #344</a>)</b>.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>1:</u> When many (<i>most</i>) P waves in a given tracing look regular (<i>or at least fairly regular</i>) — but one or two places exist in the rhythm in which P waves are not seen at the point where you expect them — it may be that <i>additional</i> P waves are “hiding”. As a result — <b>I look <i>especially</i> carefully at QRS complexes and ST-T waves that may be hiding part (</b><i>or all</i><b>) of the missing P waves</b>.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Is there any indication in <u>Figure-2</u> — that there may be <i>more</i> P waves than the ones we have labeled with <i>RED</i> arrows?</span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><span style="font-weight: bold;"> </span><u style="font-weight: bold;">HINT:</u> My answer is shown in <u style="font-weight: bold;">Figure-3</u>.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrESFSjDlXXepthhB5olPAydwE_0h3jMjONJnrDaR-f8exs3O50sshK9mNV2mquKcvomYlDIg4zn0_Cfw6eYXjiNcwqeU2q1lztoABDk-7QUVHymlSkDNGkw4wbF8WMOm8y0s_FRoigjAtPmdfl-hchoZBtHMtZOY68sZgCkcMNsa20BjEhVADG5advm0/s3790/Figure-3%20%20ECG-1%20PMcardio-RED,PINK%20(2-18.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1668" data-original-width="3790" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrESFSjDlXXepthhB5olPAydwE_0h3jMjONJnrDaR-f8exs3O50sshK9mNV2mquKcvomYlDIg4zn0_Cfw6eYXjiNcwqeU2q1lztoABDk-7QUVHymlSkDNGkw4wbF8WMOm8y0s_FRoigjAtPmdfl-hchoZBtHMtZOY68sZgCkcMNsa20BjEhVADG5advm0/w400-h176/Figure-3%20%20ECG-1%20PMcardio-RED,PINK%20(2-18.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-3:</u></b><span style="text-align: start;"> How can we <u style="font-style: italic;">know</u> if additional sinus P waves are “hiding” under the <i>PINK </i>arrows?</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>2:</u> </span><span style="font-family: arial;">It is <i>much</i> easier to recognize an ECG finding — IF you <span><i>know</i></span> that you should be looking for it!</span></span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><span style="font-family: arial;">Because we <u style="font-style: italic;">know</u> from <i>PEARL #1</i> that it would be logical for the atrial rhythm to be more regular than suggested by the <i>RED</i> arrows in <u>Figure-2</u> — <b>we need to pay <i>special</i> attention to the T waves under the <i>PINK</i> arrows</b> in <b><u>Figure-3</u> </b></span><b style="font-family: arial;">(</b><i style="font-family: arial;">since this is where we would expect P waves to be “hiding” if the underlying atrial rhythm was sinus arrhythmia</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u>QUESTION:</u></b></span></div><ul><li><span style="font-size: medium;"><b style="font-family: arial;">Is there a <i>difference</i> in ST-T wave morphology</b><span style="font-family: arial;"> for those T waves under the </span><i style="font-family: arial;">PINK</i><span style="font-family: arial;"> arrows in </span><u style="font-family: arial;">Figure-3</u><span style="font-family: arial;"> — compared to </span><u style="font-family: arial; font-style: italic;">all</u><span style="font-family: arial;"> of the other T waves in this long lead II rhythm strip? </span><b style="font-family: arial;">(</b><span style="font-family: arial;">ie, </span><i style="font-family: arial;">Compared to the T waves of beats #1,3,4,6,7,8?</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u>ANSWER:</u></b></span></div><div><span style="font-family: arial; font-size: medium;">The T waves under the <i>PINK</i> arrows in <u>Figure-3</u> are larger and clearly “fatter” than all other T waves on this tracing.</span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>3:</u> Perhaps the greatest challenge in interpreting complex rhythms is distinguishing between <b>“real differences” in morphology — <u style="font-style: italic;">vs</u> artifact</b> <i>and/or</i> the <b><i>normal</i></b> <b>variation</b> that is commonly seen in P wave, QRS and ST-T wave morphology.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">The above said — Reasons I <u style="font-style: italic;">know</u> P waves are “hiding” under the <i>PINK</i> arrows in <u>Figure-3</u> are that: <b>i<span style="color: red;">)</span> </b>It is so much<i> more logical</i> for sinus P waves to be at least <i>fairly</i> regular throughout the tracing — rather than to see the SA node suddenly stop putting out impulses <i><u>only</u></i> in 1 or 2 places in today’s tracing; <u>and</u>, <b>ii<span style="color: red;">)</span></b> There can be little doubt that the T waves under the 2 <i>PINK</i> arrows in <u>Figure-3</u> are larger and “fatter” than <u style="font-style: italic;">all</u> other T waves on this tracing.</span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><i><span style="color: red;">P</span>utting <span style="color: red;">I</span>t <span style="color: red;">A</span>ll <span style="color: red;">T</span>ogether:</i></u></b></span></div><div><span style="font-family: arial; font-size: medium;">I find it much <i>EASIER</i> to assess a complex rhythm once all sinus P waves have been labeled. For clarity — I have done this in <u style="font-weight: bold;">Figure-4</u>.</span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><i>RED</i> arrows highlight all sinus P waves. The slight variation in the P-P interval is consistent with an underlying <b><i>sinus</i></b> <b>arrhythmia</b>.</span></li><li><span style="font-family: arial; font-size: medium;">Note that there are <i>more</i> P waves (<i>RED arrows</i>) — than QRS complexes in <u>Figure-4</u>. This means that at least <i>some</i> of the <i>on-time</i> sinus P waves are <i><u>not</u></i> being conducted to the ventricles — which defines today's rhythm as <b><i>some</i> form</b> of <b><u>AV</u> <u>block</u></b>.</span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>4:</u> Today's rhythm is <i><u>not</u></i> likely to be complete (<i>3rd-degree</i>) AV block. This is because <b><i>most</i> of the time when there is complete AV block — the escape rhythm will be regular (</b><i>or at least fairly regular</i><b>)</b>. </span></li><li><span style="font-family: arial; font-size: medium;">In my experience — the <i>BEST</i> clue that a QRS complex <i><u>is</u></i> being conducted, is when we see a beat occur <i><u>earlier</u>-than-expected</i>. This is why in <u>Figure-4</u> — <b>we can <i>immediately</i> suspect</b> that <b>beats #2</b>,<b>5</b>,<b>8 <i><u>are</u></i> being conducted</b> to the ventricles. </span></li><li><span style="font-family: arial; font-size: medium;">Since today's rhythm represents <i>some</i> form of AV block — but by <i>PEARL #4, </i>is unlikely to be complete AV block — this rhythm must represent <b><i>some</i></b> <b>form</b> of <b><i>2nd-degree</i> AV block</b>. Since the QRS complex is narrow — and since we know that the Mobitz I (<i>AV Wenckebach</i>) form of 2nd-degree AV block is so much more common than Mobitz II — we can <i>immediately</i> suspect that today's challenging rhythm represents <b><i>some</i></b> <b>form</b> of <b>Mobitz I (</b><i>For review of how to distinguish the 2nd-degree AV blocks — See </i><b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-344-mobitz-i-mobitz-ii-or.html" target="_blank">ECG Blog #344</a>)</b>.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7DORMgnKiKuvutXb_vIpQJ8n0fDaMtBOWpXT85p46fPOtb3KRHcMg0-BsYIDjenFJfpi2o1gwGVZjvHBxlnHuK4nC9NcIj5dlln02svBxup5Tw2eCWsWLsqVO0XASYC8Jm_vT6lohjKjSBsokUD-_QmD8nGojzqXnxH3PQzZdmCIfAK2u2jOmdhJ-Kpw/s3768/Figure-4%20ECG-1%20Lead%20II-P%20Waves%20(3-14.1-2024)%20copy.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="518" data-original-width="3768" height="55" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj7DORMgnKiKuvutXb_vIpQJ8n0fDaMtBOWpXT85p46fPOtb3KRHcMg0-BsYIDjenFJfpi2o1gwGVZjvHBxlnHuK4nC9NcIj5dlln02svBxup5Tw2eCWsWLsqVO0XASYC8Jm_vT6lohjKjSBsokUD-_QmD8nGojzqXnxH3PQzZdmCIfAK2u2jOmdhJ-Kpw/w400-h55/Figure-4%20ECG-1%20Lead%20II-P%20Waves%20(3-14.1-2024)%20copy.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: start;"><u>Figure-4:</u></b><span style="font-family: arial; text-align: start;"> <i>RED</i> arrows highlight all sinus P waves.</span></span></td></tr></tbody></table><span style="font-size: medium;"><br /><span style="font-family: arial;"><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><i>Important</i> CONCEPTS:</u></b></span></div><div><span style="font-size: medium;"><span style="font-family: arial;">To EMPHASIZE </span><span style="font-family: arial;">— I’ve intentionally dissected the above observations regarding today’s rhythm in “slow motion”. With experience — it should take <i><u>no</u></i> <u>more</u> than <i><u>seconds</u></i> to arrive at this point in our assessment.</span></span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><i>Today's rhythm is challenging!</i> That said, the <i>KEY</i> point is — that <b>precise determination of the specific kind of AV block is <u style="font-style: italic;">not</u> essential for appropriate clinical management</b>. </span></li><li><span style="font-family: arial; font-size: medium;">All that clinicians need do — is to recognize the following: <b>i<span style="color: red;">)</span></b> That the underlying atrial rhythm is sinus arrhythmia; <b>ii<span style="color: red;">)</span></b> That <i>some</i> form of AV block <u>is</u> present <b>(</b><i>because <u>not</u> all of the sinus P waves are being conducted</i><b>)</b>; <b>iii<span style="color: red;">)</span></b> But that 3rd-degree AV block is <i><u>not</u></i> likely <b>(</b><i>because the ventricular rhythm is <u>not</u> regular</i><b>)</b>; <u>and</u>, <b>iv<span style="color: red;">)</span></b> That statistically — <b>Mobitz I 2nd-degree AV block</b> is by far <b>(</b><i>well over 90% of the time</i><b>)</b> the most common form of 2nd-degree AV block, especially when the QRS complex is narrow, as it is in today's rhythm.</span></li></ul></div><div><span style="font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">==============================</span></div><div><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>5</u> <b>(</b><i><u>Beyond</u>-the-Core</i><b>):</b> As an advanced point — <b><u>Figure-5</u></b> illustrates how using <b><i>calipers</i></b> should facilitate rapid confirmation of the <i>KEY</i> points described above.</span></div><div><ul><li><span style="font-family: arial; font-size: medium;">Using <b><i><u>calipers</u></i></b> allows us to quickly determine — that<b> the R-R intervals between beats #2-3; 3-4; 5-6; and 6-7 are all equal!</b> <b>(</b>ie, <i>142 msec.</i><b>)</b>. However, the PR intervals before beats #4 and 7 are clearly too short to conduct! This strongly suggests that each of these beats with the same preceding R-R interval <b>(</b> <i>= beats #3,4,6,7</i><b>)</b> — is a <b>junctional </b><i><u>escape</u></i><b> beat</b>.</span></li><li><span style="font-family: arial; font-size: medium;">The identical R-R interval of 142 msec. that precedes each of the above junctional escape beats — corresponds to an <b><i><u>appropriate</u></i> junctional escape rate</b> of <i>just over </i><b>40/minute (</b>ie, <i>300 ÷ 7 large boxes</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;">The reason today's rhythm is so challenging to interpret — is that the frequent occurrence of junctional escape beats serves to <i>mask</i> the typical progressive PR interval lengthening that we would otherwise see with Mobitz I 2nd-degree AV block.</span></li><li><span style="font-family: arial; font-size: medium;">That said — seeing how much <i>earlier-than-expected</i> beats #2,5 and 8 occur provides additional support to our supposition that these 3 beats are almost certain to be conducted, albeit with differing prolonged PR intervals. <i>This is why todays rhythm is so challenging to interpret!</i></span></li></ul></div><div><br /></div><div><div style="text-align: left;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgX3h6Z5g_mwH64miAniaQXAyQkbb71nl_ap862Us8BA6SkoxwU0gjc4y_999iSy5ktq-FK9uyFsToY5ipywd2SIJ69P7dmsIvnrgt53_zImo6UTb4YDltNKjYERxgDipAUDq5tlMQB1IV2FaqzWGrkQ6JHrhp-Fd38zx7t4DMF_PmCfkWIFI10YHOHpA/s3778/Figure-5%20%20ECG-1%20%20Junctional%20(2-18.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="522" data-original-width="3778" height="55" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgX3h6Z5g_mwH64miAniaQXAyQkbb71nl_ap862Us8BA6SkoxwU0gjc4y_999iSy5ktq-FK9uyFsToY5ipywd2SIJ69P7dmsIvnrgt53_zImo6UTb4YDltNKjYERxgDipAUDq5tlMQB1IV2FaqzWGrkQ6JHrhp-Fd38zx7t4DMF_PmCfkWIFI10YHOHpA/w400-h55/Figure-5%20%20ECG-1%20%20Junctional%20(2-18.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-5:</u></b><span style="text-align: start;"> Using <b><i>calipers</i></b> allows us to quickly determine that the R-R intervals between beats #2-3; 3-4; 5-6 and 6-7 are equal!</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><span style="text-align: justify;">==============================</span></span></div><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><span style="text-align: justify;"><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>What about <i>Today's</i> <span style="color: red;">1</span>2-<span style="color: red;">L</span>ead <span style="color: red;">E</span>CG?</u></b></span></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Whereas precise determination of today's rhythm is <u style="font-style: italic;">not</u> essential for appropriate clinical management — quickly recognizing that <b><i>some</i></b> <b>form</b> of <b>Mobitz I 2nd-degree AV block</b> appears to be present tremendously facilitates interpretation of today's 12-lead tracing <b>(</b><i>that I have reproduced in</i> <u style="font-weight: bold;">Figure-6</u><b>)</b>.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Overall — there is ST segment flattening with slight ST depression in multiple leads in today's 12-lead tracing.</span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>6:</u> The most common clinical setting for seeing the Mobitz I form of 2nd-degree AV block is <i>acute</i> or <i>recent</i> <b><u><i>inferior</i></u></b> and/or <b><u><i>posterior</i></u></b> <b>infarction</b>. As a result, whenever I see some form of Mobitz I — I <i>immediately</i> search for <i>any</i> possible indication of recent inferior <i>and/or </i>posterior OMI.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-size: medium;"><span style="font-family: arial;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>7:</u> Normally, there is a slight amount of gently upsloping ST elevation in <b>leads V2</b> and <b>V3</b>. When instead of this gently upsloping ST elevation, there is <b><i>"shelf-like"</i></b> <b>ST segment flattening</b> </span><span style="font-family: arial;">— I <i>immediately</i> suspect recent <b><i><u>posterior</u></i></b> <b>OMI</b>, </span><span style="font-family: arial;">especially if the patient presents with new or recent chest pain </span><b style="font-family: arial;">(</b><i style="font-family: arial;">See </i><b style="font-family: arial;"><a href="https://ecg-interpretation.blogspot.com/2023/03/ecg-blog-367-do-you-recognize-key.html" target="_blank">ECG Blog #367</a></b><i style="font-family: arial;"><b> </b>— for review of this concept</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></span></li><li><span style="font-family: arial; font-size: medium;">Therefore — <i>My "eye" was immediately drawn</i> to the abnormal ST segment flattening in <b>lead V2 (</b><i>within the RED rectangle</i><b>)</b>. Seeing a similar abnormal ST segment shape in <b><i>neighboring</i></b> <b>leads V3</b> and <b>V4 (</b><i>within the light BLUE rectangles</i><b>)</b> — confirmed this as a "real" finding.</span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">NOTE:</u> Although we are not provided with any history in today's case — knowing that today's rhythm appears to represent <i>some</i> form of Mobitz I strongly supports my supposition that the ST segment flattening with slight depression in leads V2,V3,V4 of <u>Figure-6</u> should suggest <b>recent <i>posterior</i> OMI </b><i><u>until</u></i> proven otherwise!</span></li><li><span style="font-family: arial; font-size: medium;">The finding of additional ST segment flattening in multiple other leads may represent <b><i>multi-vessel</i></b> <b>disease</b>.</span></li></ul></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiwYbY62IZYyJstfrd7aIiHFaXWSNn_LsnynSRh1TJX727oNvhWsTj2wRI0iTQ4cCv8c_qjTHLSoQJY9ijGOiOCCSdm2X1bpttmlZxj14vWhZZ_FCbx2wQZza1e6lM5QP7yT6loYIcIn9jAlyZTdBvLSmktCZHK_nVxbV6s4-rlRiAuzdMe2rqtBG06khg/s3784/Figure-4%20%20ECG-1%20Post%20OMI%20(2-18.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1668" data-original-width="3784" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiwYbY62IZYyJstfrd7aIiHFaXWSNn_LsnynSRh1TJX727oNvhWsTj2wRI0iTQ4cCv8c_qjTHLSoQJY9ijGOiOCCSdm2X1bpttmlZxj14vWhZZ_FCbx2wQZza1e6lM5QP7yT6loYIcIn9jAlyZTdBvLSmktCZHK_nVxbV6s4-rlRiAuzdMe2rqtBG06khg/w400-h176/Figure-4%20%20ECG-1%20Post%20OMI%20(2-18.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-6:</u></b><span style="text-align: start;"> I've highlighted the <i>KEY</i> leads in today's 12-lead tracing with colored rectangles (<i>See text</i>).</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span style="text-align: justify;">==============================</span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>8</u><span style="font-weight: bold;"> (</span><i><u>Beyond</u>-the-Core</i><span style="font-weight: bold;">):</span> There will sometimes be slight variation in QRS morphology between <i>sinus-conducted</i> beats and <i>junctional</i> escape beats. At times, this slight difference in QRS morphology provides an important clue as to whether a given beat is conducted — <i><u>or</u></i> — represents a junctional escape beat <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2013/03/ecg-interpretation-review-63-av-block.html" target="_blank">ECG Blog #63</a>)</b>.</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">I've emphasized that although the precise mechanism of today's rhythm is complex — all that is needed for appropriate clinical management, is appreciation that some form of Mobitz I 2nd-degree AV block is present.</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">at <b><i>some</i></b> <b>form</b> of Mobitz I 2nd-degree AV block is present.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><i>Did YOU notice</i> the slight difference in QRS morphology between the 2 beats in <i>simultaneously-recorded</i> leads V1,V2 and V3 in <u>Figure-6</u>? This difference in QRS shape further supports my earlier conclusion that <b>beat #5 (</b><i>that occurs earlier-than-expected</i><b>)</b> is <i>sinus-conducted</i> with a long PR interval — whereas <b>beat #6 (</b><i>which is preceded by the 142 msec. R-R interval shown in </i><u>Figure-5</u><b>)</b> is a junctional escape beat.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><span style="text-align: justify;">==============================</span></span></div><div><span style="font-family: arial; font-size: medium;"><span style="text-align: justify;"><br /></span></span></div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><b><u>The <span style="color: red;">L</span>ADDERGRAM:</u></b> </div><div style="text-align: justify;">I've emphasized that although the precise mechanism of today's rhythm is complex — all that is needed for appropriate clinical management, is appreciation that <b><i>some</i></b> <b>form</b> of <b>Mobitz I 2nd-degree AV block</b> is present.</div></span><div><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">That said — I fully acknowledge that I needed a laddergram to "solve" <b>(</b>ie, <i>explain</i><b>)</b> each of the ECG findings in today's tracing. I've labeled my proposed laddergram in <u style="font-weight: bold;">Figure-7</u>.</span></li></ul></div><div><span style="font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div style="font-family: -webkit-standard;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiifj94QyqHKnIZrqd7MZYESEbzrFJg5FEdRZX-vRj3Ytb2XeQtGCWiP6BsWSSWMQLJl086o0dnFJQjid_WEvIOyPeJzPj0jICdKC4bBMnP6i5hNER64dhbkTaQFsxMr3kVr0Tv6bb6jaOexixEfx0lzY6rO7hBJwyaPgAY5tuyMtaYDwICVvOk9XH75iQ/s3702/Figure-7%20%20Ladder-2%20(2-18.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1542" data-original-width="3702" height="166" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiifj94QyqHKnIZrqd7MZYESEbzrFJg5FEdRZX-vRj3Ytb2XeQtGCWiP6BsWSSWMQLJl086o0dnFJQjid_WEvIOyPeJzPj0jICdKC4bBMnP6i5hNER64dhbkTaQFsxMr3kVr0Tv6bb6jaOexixEfx0lzY6rO7hBJwyaPgAY5tuyMtaYDwICVvOk9XH75iQ/w400-h166/Figure-7%20%20Ladder-2%20(2-18.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-7:</u></b><span style="text-align: start;"> I've labeled my proposed laddergram in today's case.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="font-family: -webkit-standard; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="font-family: -webkit-standard; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>Laddergram Explanation:</u></b></span></div><div style="text-align: justify;"><ul><li><b>Beats #2</b>, <b>5</b> and <b>8</b> are each <b><i>sinus-conducted</i></b>, albeit with significantly prolonged PR intervals <b>(</b><i>since each of these beats occur much <u>earlier</u>-than-expected</i><b>)</b>.</li><li><b>Beats #3</b>,<b>4</b>,<b>6</b> and <b>7</b> are <b>junctional <i>escape</i> beats</b>. We arrived at this conclusion by the finding of PR intervals before beats #4 and 7 that are <i>definitely too short</i> to conduct — with the PR intervals before beats #3 and 6 being significantly shorter than each of the sinus-conducted beats — <u>and</u>, with <i>each</i> of these 4 beats that we presume to be junctional escape beats, being preceded by the <i>identical</i> R-R interval of 142 milliseconds. </li><li>Although we do not see far enough in front of beat #1 to know what its preceding R-R interval is — the fact that the PR interval before <b>beat #1</b> is short <b>(</b><i>and of similar duration as the PR interval preceding junctional beats #3 and 6</i><b>)</b> — suggests that <b>beat #1</b> is <i>also</i> a <b>junctional <i>escape</i> beat</b>.</li><li><i>YELLOW</i> arrows represent P waves that are <i><u>not</u></i> conducted <i>because of </i>the 2nd-degree AV block.</li><li>We have <u style="font-style: italic;">no</u> idea whether the <i>BLUE</i> arrow P waves might have conducted <b>(</b><i>perhaps with an increasing PR interval</i><b>)</b> — IF the junctional escape beats <b>(</b> = <i>beats #3,4; 6,7</i><b>)</b> would not have occurred.</li><li><br /></li><li><u style="font-weight: bold;">BOTTOM Line:</u> Today's case illustrates how challenging it can be to recognize certain forms of 2nd-degree AV block of the <b>Mobitz I</b> <b>type</b> <b>(</b>ie, <i>in which there are frequent junctional escape beats</i><b>)</b>. That said — the <b><i>overall</i> ventricular rate</b> of today's rhythm is <b><i>between</i></b> <b>40-50/minute</b>, which may be enough to maintain hemodynamic stability. </li><li><u style="font-weight: bold;">NOTE:</u> We can <u style="font-style: italic;">not</u> say there is "high-grade" AV block in today's tracing — because we <u style="font-style: italic;">never</u> see 2 consecutive <i>on-time</i> sinus P waves that fail to conduct <u style="font-style: italic;">despite</u> having adquate opportunity to do so <b>(</b>ie,<i> We <u>never</u> see 2 consecutive YELLOW arrow P waves</i><b>)</b>.</li><li><u style="font-weight: bold;">Clinically:</u> The "good news" regarding today's case — is that most of the time with Mobitz I, acute reperfusion <b>(</b><i>with PCI or thrombolytics</i><b>)</b> will result in improvement of the associated AV conduction disturbance.</li></ul></div><div style="font-family: -webkit-standard;"><br /></div><div style="font-family: -webkit-standard; text-align: justify;"><span style="font-family: arial; font-size: medium;">I conclude today's case with the laddergram shown in <u style="font-weight: bold;">Figure-8</u> — in which I've removed the coloration from Figure-7. </span></div></span></div><div><span style="font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgoxnUAmS02NGGbaoZnkCYb9uesWhVZ6Cz7iNuJ8DjcVJ794WzkbH8-hkOfyOBfIFLTv_903CiVJwd3ZU8A7YRcsMaTmBha7grqexdZ3Dpx9xz5NeTNSiNZMYE5edOMofud0-n0qJ6CxRyqK_gbfhFglHjbInk2J9Y_o6ERYGPNAwhJILaj7l5zrLs1zhY/s3726/Figure-6%20%20Ladder-1%20(2-18.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1536" data-original-width="3726" height="165" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgoxnUAmS02NGGbaoZnkCYb9uesWhVZ6Cz7iNuJ8DjcVJ794WzkbH8-hkOfyOBfIFLTv_903CiVJwd3ZU8A7YRcsMaTmBha7grqexdZ3Dpx9xz5NeTNSiNZMYE5edOMofud0-n0qJ6CxRyqK_gbfhFglHjbInk2J9Y_o6ERYGPNAwhJILaj7l5zrLs1zhY/w400-h165/Figure-6%20%20Ladder-1%20(2-18.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-8:</u></b><span style="text-align: start;"> Today's laddergram without coloration.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div><p class="MsoNormal" style="margin: 0in;"><span>==========================================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in;"><span><span><span><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Danilo Franco</span></span><span style="caret-color: rgb(5, 5, 5); color: #050505;"> (</span><i style="caret-color: rgb(5, 5, 5); color: #050505;">from Italy</i><span style="caret-color: rgb(5, 5, 5); color: #050505;">) for the case and this tracing.</span></span></p><p class="MsoNormal" style="margin: 0in;"><span>==========================================</span></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span><br /></span></p><div class="separator" style="clear: both;"><span><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"></a></span></div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></span><span><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span> </span></p></div><div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span>============================== <o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><ul><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a> </b>— My <b><i><u>P</u>s,<u>Q</u>s,3<u>R</u></i> System</b> for <b><i><u>Rhythm</u></i></b> <b>interpretation</b>.</span></span></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> <i>draw</i> <b><u>Laddergrams</u> </b></span></span><span><b>(</b><i>w</i></span><i>ith LINKS to more than 100 laddergram cases — many with step-by-step sequential illustration</i><b>)</b><span>.</span></li></ul><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" style="font-weight: bold;" target="_blank">ECG Blog #205</a><b> </b>— Reviews my <b><i><u><span>S</span>ystematic</u></i></b> <b><span>A</span>pproach</b> to <b>12-lead ECG Interpretation</b>.</span></li></ul><div style="text-align: justify;">=================================</div><div style="text-align: justify;"><ul><li><b><a href="https://ecg-interpretation.blogspot.com/p/new-ecg-videos-december-2023.html" target="_blank">CLICK HERE</a></b> <b>—</b> for my <b>6 <i><u>new</u></i> ECG <u><span style="color: red;">V</span>ideos</u> (</b>on Rhythm interpretation — 12-lead interpretation with Case Studies for ECG diagnosis of <b><i>acute</i> <u>OMI</u>)</b>.</li><li><b><a href="https://ecg-interpretation.blogspot.com/p/new-ecg-podcasts-2024-metodo.html" target="_blank">CLICK HERE</a></b> <b>—</b> for my <b>2 <i><u>new</u></i> ECG <u><span style="color: red;">P</span>odcasts</u> (</b>on ECG & Rhythm interpretation Errors — <u>and</u> — Errors in assessing for <b><i>acute</i> <u>OMI</u>)</b>.</li></ul></div><div style="text-align: justify;">=================================</div><ul><li style="text-align: justify;"><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" style="font-weight: bold;" target="_blank">ECG Blog #192</a> — The <b>3 <i><u>Causes</u></i></b> of <b>AV Dissociation</b>. </li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-191-ecg-mp-8-is-av-block.html" target="_blank">ECG Blog #191</a></b> — Reviews the difference between <b>AV Dissociation</b> <u>vs</u> <b><i>Complete</i> AV Block</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2023/08/ecg-blog-389-quote-from-sherlock-holmes.html" target="_blank">ECG Blog #389</a></b> — <b><a href="https://ecg-interpretation.blogspot.com/2023/04/ecg-blog-373-86yo-and-this-rhythm.html" target="_blank">ECG Blog #373</a></b> — for review of some cases that illustrate <b><i>"AV block problem-solving"</i></b>.</li><li style="text-align: justify;"><b style="text-align: left;"><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-344-mobitz-i-mobitz-ii-or.html" target="_blank">ECG Blog #344</a></b><span style="text-align: left;"> — thoroughly reviews the </span><b style="text-align: left;"><i><u>Types</u></i></b><span style="text-align: left;"> of </span><b style="text-align: left;">2nd-degree AV block (</b><i style="text-align: left;">Mobitz I <u>vs</u> Mobitz II <u>vs</u> 2:1 AV Block</i><b style="text-align: left;">)</b><span style="text-align: left;">.</span></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-267-75-group-beating-and.html" target="_blank">ECG Blog #267</a></b> — Reviews with <b><i>step-by-step</i></b> <b><u>laddergrams</u></b>, the derivation of a case of Mobitz I with more than a single possible explanation.</li></ul><div style="text-align: justify;">=================================</div><div style="text-align: justify;"><span style="text-align: left;"><span><div style="text-align: justify;"><ul><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-193-ecg-mp-10-acute-omi.html" target="_blank">ECG Blog #193</a></b> — Reviews the <b><i><span style="color: red;">M</span>irror</i></b> <b><span style="color: red;">T</span>est</b> for recognition of <b>acute <i>Posterior</i> MI</b>. This blog post also reviews the basics for <i><u>predicting</u></i> the <b><i>"<span style="color: red;"><span>C</span></span>ulprit"</i></b> <b><span style="color: red;">A</span>rtery </b>— and use of the term, <b>"<span style="color: red;">O</span>MI" ( </b>= <i><b><u>O</u></b>cclusion-based </i><b><u><i>MI</i></u>)</b> as an improvement from the <i><u>outdated</u></i> STEMI paradigm.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2023/03/ecg-blog-367-do-you-recognize-key.html" target="_blank">ECG Blog #367</a></b> — <i>A <u><b>must</b></u> to review !!!</i> — as this case reinforces the <i>KEY</i> concepts for <b>recognizing <i>subtle</i> acute <i><u>posterior</u></i> OMI!</b></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2022/03/ecg-blog-294-one-hour-later.html" target="_blank">ECG Blog #294</a></b> — How to tell IF the <b><i>"culprit" </i>artery</b> has <b><u>reperfused</u></b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-260-repolarization-change.html" target="_blank">ECG Blog #260</a></b> — Reviews when a T wave is <b><i><u>hyperacute</u></i></b> — and the concept of <b><i>"<u>dynamic</u>" </i>ST-T wave changes</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/06/ecg-blog-230-46-are-there-serial-ecg.html" target="_blank">ECG Blog #230</a></b> — How to <b><i><u>compare</u></i></b> <b><i>serial</i></b> <b>ECGs</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2022/10/ecg-blog-337-nstemi-or-omi.html" target="_blank">ECG Blog #337</a></b> — an <b>OMI</b> <i><u><b>misdiagnosed</b></u></i> as an <b>NSTEMI</b> ...</li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2022/02/ecg-blog-285-wider-irregular-rhythm.html" target="_blank">ECG Blog #285</a></b> — </span><span>for another example of <b>acute <i>Posterior</i> MI (</b><i>with <u>positive</u> </i><b><i>Mirror </i>Test)</b>.</span></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/08/ecg-blog-246-60-what-is-mirror-test.html" target="_blank">ECG Blog #246</a></b> — for another example of <b>acute <i>Posterior</i> MI (</b><i>with <u>positive</u></i> <b><i>Mirror</i> Test)</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2013/12/ecg-interpretation-review-80-acute.html" target="_blank">ECG Blog #80</a></b> — reviews prediction of the "culprit" artery (<i>with another case to illustrate the</i> <b><i>Mirror</i></b> <b>Test</b> <i>for diagnosis of </i><b>acute <i>Posterior</i> MI</b>).</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-184-audio-pearl-2-magical-lead.html" target="_blank">ECG Blog #184</a></b> — illustrates the <b><i>"magical"</i></b> <b>mirror-image opposite relationship</b> with acute ischemia between <b>lead III</b> <u>and</u> <b>lead aVL (</b><i>featured in Audio Pearl #2 in this blog post</i><b>)</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2019/07/ecg-blog-167-reciprocal-omi-normal.html" target="_blank">ECG Blog #167</a></b> — another case of the <b><i>"magical"</i> mirror-image opposite relationship</b> between <b>lead III</b> <u>and</u> <b>lead aVL </b>that confirmed acute OMI.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-271-79-what-is-st-segment.html" target="_blank">ECG Blog #271</a></b> — Reviews determination of the ST segment baseline <b>(</b><i>with discussion of the entity of </i><b><i>diffuse Subendocardial</i> Ischemia)</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/10/ecg-blog-258-mp-70-how-to-date-mi.html" target="_blank">ECG Blog #258</a></b> — How to <b><i>"<u><span>D</span>ate</u>"</i></b> an <b><span>I</span>nfarction</b> based on the <i>initial</i> ECG.</li><li style="text-align: justify;">The importance of the <b><i><u>new</u></i></b> <b>OMI (</b><i>vs the old STEMI</i><b>) Paradigm</b> — See <i>My Comment </i>in the <b><a href="https://hqmeded-ecg.blogspot.com/2020/07/omi-nomi-paradigm-established-as-better.html" target="_blank">July 31, 2020</a> post</b> in Dr. Smith's ECG Blog.</li></ul><div><br /></div></div></span></span></div></div></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></span><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span></p></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-size: medium;"><br /></span></div></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div><div><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div><br /></div></div></span></span></div></div></div></span></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-64925873450803566592024-03-11T05:00:00.000-04:002024-03-11T05:00:00.720-04:00ECG Blog #420 — A "Fast" Complete Heart Block?<div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;">I was asked to interpret the 2-lead rhythm strip shown in <u style="font-weight: bold;">Figure-1</u> — without the benefit of any history. <i>What are YOUR thoughts?</i></div><div style="text-align: justify;"><ul><li>Is there <b>AV block?</b> If so — <i>Is it <u>complete</u> AV block?</i></li></ul></div></span><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9zo-mBKD9QHHStUDAd4vew9LGKmkpfwxqTP4jTAF3H-NXjVJhHm13Z6XrjnCs9bSXDsOo-_Xp_RvM3vrzFB1nIDF-KHzkjJKpfQfIjVG8A-oK04IlI8K2L8hkxNCk-jHPmOPq-vmSbDifMlXMc2StjCPmJqrn_gSGSs5qsmOqtP3YzWYBRRu_tlM7Poo/s3528/Figure-1%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="608" data-original-width="3528" height="69" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9zo-mBKD9QHHStUDAd4vew9LGKmkpfwxqTP4jTAF3H-NXjVJhHm13Z6XrjnCs9bSXDsOo-_Xp_RvM3vrzFB1nIDF-KHzkjJKpfQfIjVG8A-oK04IlI8K2L8hkxNCk-jHPmOPq-vmSbDifMlXMc2StjCPmJqrn_gSGSs5qsmOqtP3YzWYBRRu_tlM7Poo/w400-h69/Figure-1%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-1:</u></b><span style="text-align: justify;"> You are asked to interpret this 2-lead rhythm strip <u style="font-style: italic;">without</u> the benefit of any history.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><p class="MsoNormal" style="margin: 0in;"><span style="color: #050505;"><span style="caret-color: rgb(5, 5, 5);">======================</span></span></p><p class="MsoNormal" style="margin: 0in;"><span style="color: #050505;"><span style="caret-color: rgb(5, 5, 5);"><b><u>NOTE:</u></b> Today's rhythm <u style="font-style: italic;">is</u> challenging — especially if you have not seen this type of rhythm before. That said, attention to the <i>sequential PEARLS </i>I present in my discussion below can greatly facilitate recognizing this rhythm <i><u>within</u></i> seconds the next time you encounter it!</span></span></p><p class="MsoNormal" style="margin: 0in;"><span style="color: #050505;"><span style="caret-color: rgb(5, 5, 5);">======================</span></span></p><p class="MsoNormal" style="margin: 0in;"><span style="color: #050505;"><span style="caret-color: rgb(5, 5, 5);"><br /></span></span></p><p class="MsoNormal" style="margin: 0in;"><span><b><u><span style="color: #050505;"><i>MY Thoughts</i> on <i>Today’s</i> Rhythm:</span></u></b><span style="color: #050505;"> </span></span></p><p class="MsoNormal" style="margin: 0in;"><span><span style="color: #050505;">Assuming that today’s patient is <u style="font-style: italic;">not</u> unstable hemodynamically <b>(</b><i>and does <u>not</u> require immediate synchronized cardioversion</i><b>)</b> — We can completely turn our attention to assessment of the rhythm. By the </span><b><u><span style="color: red;">P</span></u></b><b><span style="color: #050505;">s, </span></b><b><u><span style="color: red;">Q</span></u></b><b><span style="color: #050505;">s & 3</span></b><b><u><span style="color: red;">R</span></u></b><span><b style="color: #050505;"> Approach (</b><i style="color: #050505;">which I review on </i><b><span style="color: #050505;"><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></span><span style="color: #050505;">):</span></b></span></span></p><ul style="text-align: left;"><li style="text-align: justify;"><span style="color: #050505;"><span style="caret-color: rgb(5, 5, 5);">The <b><u>R</u>ate</b> of the rhythm in <u>Figure-1</u> is somewhat <i style="font-weight: bold;">fast </i>— averaging <b>~100/minute (</b>ie, <i>with an R-R interval close to 3 large boxes in duration for most of the tracing</i><b>)</b>.</span></span></li><li style="text-align: justify;"><span style="color: #050505;"><span style="caret-color: rgb(5, 5, 5);">The rhythm is clearly <b><u style="font-style: italic;">not</u> <u>R</u>egular</b>. The R-R interval is not the same throughout the tracing.</span></span></li><li style="text-align: justify;"><span style="color: #050505;"><span style="caret-color: rgb(5, 5, 5);">It appears that there <u style="font-style: italic;">are</u> at least some <b><u>P</u> waves</b>, albeit P waves are <u style="font-style: italic;">not</u> seen in all parts of this tracing.</span></span></li><li style="text-align: justify;"><span><span style="color: #050505;">Although the <b><u>Q</u>RS complex</b> looks wider than it normally is — the QRS does <u style="font-style: italic;">not</u> measure more than half a large box <b>(</b>ie, <i><u>not</u> more than 0.10 second</i><b>) </b>in either of the 2 monitoring leads shown in <u>Figure-1</u>. </span></span></li></ul></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>1:</u> Remember the saying, <i><b>“12 leads are <u>better</u> than one”</b>. </i>The importance of determining whether the QRS complex of a tachycardia is wide or narrow — is that IF the QRS is narrow in all 12 leads, then the rhythm is <b><u style="font-style: italic;">supraventricular</u> (</b><i>and we have therefore ruled out the possibility of VT = Ventricular Tachycardia</i><b>)</b>. The more monitoring leads we have available — the more accurate will be our determination about whether the QRS is wide or narrow.</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>2:</u> We <u style="font-style: italic;">only</u> see 2 of the 12 leads of an ECG in <u>Figure-1</u>. This is important to appreciate — since sometimes a part of the QRS complex may lie on the baseline in one or more leads. When this happens — the QRS may “look” to be narrow in the lead(s) you are monitoring, whereas in reality the QRS is actually wide.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">It is for this reason that I always favor <b><i>doing</i></b> a <b>12-lead ECG</b> as soon as this is feasible for <i>any</i> arrhythmia of <i>uncertain</i> etiology. Clinical management of the patient clearly differs if you can rule out the possibility of a ventricular rhythm. Unfortunately in today’s case — <i>No 12-lead ECG was available.</i></span></li></ul><div><span style="font-family: arial; font-size: medium;"><i><br /></i></span></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>Assessing the 5th Parameter:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Thus far — We’ve determined the following: </span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">That the <b><u>R</u>ate</b> of QRS complexes in today’s rhythm is fairly fast — but <u style="font-style: italic;"><b>not</b></u> quite <b><u>R</u></b>egular.</span></li><li><span style="font-family: arial; font-size: medium;">That the rhythm is probably supraventricular <b>(</b><i>because the </i><b><u>Q</u>RS</b><i> is </i><u style="font-style: italic;">not</u><i> more than half a large box in either of the 2 monitoring leads we are given</i><b>)</b></span></li><li><span style="font-family: arial; font-size: medium;">That at least <i>some</i> <b><u>P</u></b> <b>waves</b> are present.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">The remaining parameter is the <b>3rd </b><u style="font-weight: bold;">R</u> — which is determining IF any of the P waves in today’s rhythm are <b><u>R</u>elated</b> to <b><i>neighboring</i></b> <b>QRS</b> <b>complexes</b>. It turns out that this last parameter is <i>KEY</i> to solving today’s arrhythmia.</span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>3:</u> The <i>easiest</i> way to assess for this 5th parameter — is to see if there are any PR intervals that repeat. And the <i>BEST</i> way to find any PR intervals that may be repeating — is to <b><i>seek out any relative <u>pauses</u> in the rhythm</i></b> — and to check out the PR interval before <i>each</i> beat that ends <i>each</i> pause.</span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">NOTE:</u> The “pause” in the rhythm may be brief — and <u style="font-style: italic;">not</u> much longer than the other R-R intervals. <u style="font-weight: bold;">Figure-2</u> illustrates this principle — in which the R-R intervals between beats #4-5; 8-9; and 12-13 are slightly longer than other R-R intervals in today’s tracing.</span></li><li><span style="font-family: arial; font-size: medium;"><i>RED arrows</i> highlight the P waves that precede each of the beats that end each of these short pauses. <i>Isn’t the PR interval before <b>beats #5</b>, <b>9</b> and <b>13</b> equal?</i></span></li></ul><div><span style="font-family: arial; font-size: medium;"><i><br /></i></span></div></div><div><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>4:</u> An important concept in <i>“arrhythmia problem solving” </i>— is based on the saying, <i style="font-weight: bold;">“Birds of a Feather flock Together”</i>. By this I mean that IF you see a certain ECG finding a number of times in a given tracing — then if you see a <i>similar</i> phenomenon that is not quite as precise — <b><i>the chances are that you are seeing the <u>same</u> ECG finding!</i></b></span></div><div><ul><li><span style="font-family: arial; font-size: medium;">Take <b>beat #1</b> in <u>Figure-2</u> — which occurs at the very beginning of this tracing <b>(</b><i>which means that we do <u>not</u> know what came before beat #1</i><b>)</b>. As a result, we can <u style="font-style: italic;">not</u> know if beat #1 was preceded by a slight pause in the same way that beats #5, 9 and 13 are all preceded by a slight pause of the same duration. </span></li><li><span style="font-family: arial; font-size: medium;">BUT — Given the <i>repetitive </i>pattern of there being a slight pause after every 4th beat <b>(</b>ie, <i><b>“Birds of a feather …” </b></i><b>)</b> — and given that the PR interval preceding beat #1 <b>( </b><i>= first RED arrow in Figure-2</i><b>) </b>is equal to the PR interval preceding beats #5,9,13 <b>(</b><i> = the other RED arrows in Figure-2</i><b>)</b> — this is <u style="font-style: italic;">not</u> by chance, and whatever relationship might be occurring between atrial activity and neighboring QRS complexes for beats #5-thru-16 — is almost certain to be the <u style="font-style: italic;">same</u> phenomenon occurring for beats #1-thru-5! </span></li></ul></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZ5SAebr5w0vjh7AmKGaaTYn8_XSaBIsQDlJh5XoVUI_Z2lQZliVNjIOrXsEhMqN4O0JglBVgSvDPc2Pd4kc7ZQAQXe-BsbwF0RPhE_qMX7eVwOOvik2uiutQJ8xgRnxggNVpVBKkM3WZLdhRhuGtSng28QeqnyhLNke69x9mMVqMawjdWvpVKrGjvWiw/s3530/Figure-2%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="612" data-original-width="3530" height="69" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZ5SAebr5w0vjh7AmKGaaTYn8_XSaBIsQDlJh5XoVUI_Z2lQZliVNjIOrXsEhMqN4O0JglBVgSvDPc2Pd4kc7ZQAQXe-BsbwF0RPhE_qMX7eVwOOvik2uiutQJ8xgRnxggNVpVBKkM3WZLdhRhuGtSng28QeqnyhLNke69x9mMVqMawjdWvpVKrGjvWiw/w400-h69/Figure-2%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-2:</u></b><span style="text-align: justify;"> Applying the concept of <i>“Looking for a slight pause in the rhythm” </i><span><i>— </i>I’ve labeled the 4 P waves that we clearly see with <i>RED</i> arrows. Note that the PR interval for these 4 P waves is the same!</span></span></span></td></tr></tbody></table><span style="font-size: medium;"><span style="font-family: arial;"><br /></span></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><b><u>PEARL <span style="color: red;">#</span>5:</u></b> It’s time to determine IF there is an underlying regular atrial rhythm — which <i>could be the case</i> IF some P waves are hiding within certain ST-T waves. <u style="font-weight: bold;">Figure-3</u> illustrates <i style="font-weight: bold;">How to Look for “Hidden” P waves:</i></span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Search the tracing looking for 2 P waves in a row that you can clearly see. <i>RED</i> arrows in <u>Figure-3</u> illustrate 2 such P waves that are clearly seen in today’s rhythm.</span></li><li><span style="font-family: arial; font-size: medium;">Using the P-P interval set by these 2 <i>RED</i> arrows locates the <i>next</i> spot to search for a “P wave in hiding”. <i>Isn’t the T wave under the WHITE arrow in </i><u>Figure-3</u><i> “fatter” than most other T waves in this tracing?</i></span></li><li><span style="font-family: arial; font-size: medium;">The reason the T wave under the <i>WHITE</i> arrow is “fatter” — is that this is where the next consecutive P wave occurs.</span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">NOTE:</u> Using <u style="font-style: italic; font-weight: bold;">calipers</u> greatly facilitates the process. Using calipers <i>instantly</i> makes you “smarter” — and allows me to “solve” an arrhythmia such as today’s tracing <u style="font-style: italic;">within</u> seconds that providers who do not use calipers are simply <u style="font-style: italic;">not</u> able to solve.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkK7qewqrbvzg4y5LkoXh9BXCFphxpENywnoPyzPS-_OR-16QhAduMtf1jyJ484w8N-eYNJWRUTWQGnzXsqYQZQRMEUvWVbM0WTZmfMC67cYIPZBGDe5CF07-qDmj-5ESnOUfuTPLtZH5xH5-UGqBZRcSbxRvyFxs1fTUbryLi-UFLaWIfIiTgTtSNQdY/s3528/Figure-3%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="604" data-original-width="3528" height="69" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkK7qewqrbvzg4y5LkoXh9BXCFphxpENywnoPyzPS-_OR-16QhAduMtf1jyJ484w8N-eYNJWRUTWQGnzXsqYQZQRMEUvWVbM0WTZmfMC67cYIPZBGDe5CF07-qDmj-5ESnOUfuTPLtZH5xH5-UGqBZRcSbxRvyFxs1fTUbryLi-UFLaWIfIiTgTtSNQdY/w400-h69/Figure-3%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-3:</u></b><span style="text-align: justify;"> How to find <i>“hidden”</i> P waves (<i>See text</i>).</span></span></td></tr></tbody></table><span style="font-size: medium;"><span style="font-family: arial;"><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Now that we have identified the P-P interval for 3 consecutive P waves <b>(</b><i>as shown by the 3 arrows in </i><u>Figure-3</u><b>)</b> — it should take <u style="font-style: italic;">no</u><i> </i><u style="font-style: italic;">more</u> than seconds to “walk out” where the <i>regularly-occurring</i> P waves are located throughout the rest of today’s tracing (<u style="font-weight: bold;">Figure-4</u>):</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitQhDtg8tyVHFHP2-ol36g-QF42Hztob0xRLCZfhZftKrMTqJTh-s_WkjpW51AlzQeFgTQdW0DSarTEmhTrz_FD_ss6vJjdA9k3ZdVBSoXAqOQaFwiOIAUaV93gHSQpJacgc-XkAe3aOdtE0_zoT6dm9Bw1nCHuSe3Sx3H4LawMaT8NvJbUk6T2EDuxho/s3532/Figure-4%20%20Lead%20II%20P%20waves%20(1-29.22-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="614" data-original-width="3532" height="70" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitQhDtg8tyVHFHP2-ol36g-QF42Hztob0xRLCZfhZftKrMTqJTh-s_WkjpW51AlzQeFgTQdW0DSarTEmhTrz_FD_ss6vJjdA9k3ZdVBSoXAqOQaFwiOIAUaV93gHSQpJacgc-XkAe3aOdtE0_zoT6dm9Bw1nCHuSe3Sx3H4LawMaT8NvJbUk6T2EDuxho/w400-h70/Figure-4%20%20Lead%20II%20P%20waves%20(1-29.22-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-4:</u></b><span style="text-align: justify;"> <i>RED</i> arrows highlight where regular atrial activity is located throughout the rhythm in today’s case.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>6:</u> Try to <b>determine if the underlying atrial rhythm is a “sinus” rhythm </b>— or an ectopic atrial rhythm. This determination is <i><u>not</u></i> always easy to make.</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">A <b><u style="font-style: italic;">sinus</u> rhythm</b> — is defined by the presence of an upright P wave in lead II. This is because when limb lead electrodes are correctly placed — the direction of atrial depolarization as impulses arising from the SA node travel toward the AV node will be oriented close to +60 degrees in the frontal plane, which corresponds to the 60 degree electrical perspective of standard lead II in Einthoven’s Triangle.</span></li><li><span style="font-family: arial; font-size: medium;">Therefore — <b>IF P waves are not upright in lead II, then the rhythm is <u style="font-style: italic;">not</u> sinus!</b></span></li><li><span style="font-family: arial; font-size: medium;">The problem is that when P waves <u style="font-style: italic;">are</u> upright in standard lead II <b>(</b><i>as they are in Figure-4</i><b>)</b> — then it may be difficult to distinguish between a sinus rhythm <u style="font-style: italic;">vs</u> an ectopic atrial rhythm!</span></li></ul><span style="font-family: arial; font-size: medium;"><span><div style="text-align: justify;"><span><br /></span></div><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>7:</u> Determining the atrial rate may help. In <u>Figure-4</u> — the <b><i>atrial</i></b> <b>rate</b> is <b>~125/minute</b><b> (</b><i>which can be quickly estimated by the Every-Other-Beat Method reviewed in </i><b><a href="https://ecg-interpretation.blogspot.com/2021/04/blog-210-ecg-mp-27-regular-wct-how-fast.html" target="_blank">ECG Blog #210</a>)</b>. </span><br /></span><ul><li><span style="font-family: arial; font-size: medium;">By the <b><i>Every-<u>Other</u>-Beat </i>Method </b><i>— </i>Given that the P-P interval of <i>every-<u>other</u>-P-wave</i> in Figure-4 is just <i>under</i> 5 large boxes in duration — this means that <u style="font-style: italic;">half</u> the atrial rate is slightly <i>faster</i> than 300 ÷ 5 (ie, <i>slight <u>faster</u> than 60/minute</i>) — which means the <b>actual <i>atrial</i> rate</b> is <b>~125/minute</b>.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">The <u style="font-weight: bold;">PEARL:</u> The finding of a fast <u>and</u> regular atrial rate in association with an irregular supraventricular (<i>narrow-QRS</i>) rhythm — is much more likely to represent <b>ATach (</b><i>an ectopic <u>A</u>trial <u>T</u>achycardia</i><b>)</b> — than sinus tachycardia. The reason for this finding, is that <b><i>Wenckebach</i></b> <b>conduction</b> is <i>commonly</i> seen with <b><i>ectopic</i></b> <b>ATach</b>.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="caret-color: rgb(5, 5, 5); color: #050505;"><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="caret-color: rgb(5, 5, 5); color: #050505;">======================</span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><i><u><span style="color: red;">P</span>roving <span style="color: red;">M</span>y <span style="color: red;">T</span>heory</u> . . .</i></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Using calipers — I was able to prove <i><u>within</u></i> seconds that my suspicion of ATach with Wenckebach conduction was the answer to today's rhythm.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">For clarity in <u style="font-weight: bold;">Figure-5</u> — I've reproduced Figure-2, in which we see <b><u style="font-style: italic;">group</u> beating (</b>ie, <i>beats #1-thru-4; #5-thru-8; #9-thru-12; #13-thru-16</i><b>) </b>— with each group separated by a <i style="font-weight: bold;">slight </i><u style="font-weight: bold;">pause</u> of similar duration<b> (</b>ie, <i>between beats #4-5; #8-9; #12-13</i><b>)</b> — with each pause ending with a <b><i>conducted</i></b> <b>P wave (</b>ie, <i>the RED arrow P waves, each with an identical PR interval before beats #1,5,9,13</i><b>)</b>. <b>The <i>repetitive </i>pattern of these similarities can <u style="font-style: italic;">not</u> be by chance!</b></span></li><li><span style="font-family: arial; font-size: medium;">As soon as my calipers confirmed the underlying regular atrial rhythm <b>(</b><i>RED arrows in </i><u>Figure-4</u><b>) — </b>I <i>knew</i> today's rhythm had to be ATach with Wenckebach conduction.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCo-s2IkPqtvdek4gcnRZ6CTnTyLE1IGze6XHdfAUYaPK69uQqGc2P2CIfKtjrEVwi6B3xoNUliTXEC1M5-8VEthIjWSVt1IYS98KmYmN7FcuqZ26dDeXKhYQIpFItgZB8IAPPTUqFkIho5UxxTnOg_xOY8oAwl-afo5YCPWea48rvH666z3WIpMUgs5c/s3530/Figure-5%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="612" data-original-width="3530" height="69" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgCo-s2IkPqtvdek4gcnRZ6CTnTyLE1IGze6XHdfAUYaPK69uQqGc2P2CIfKtjrEVwi6B3xoNUliTXEC1M5-8VEthIjWSVt1IYS98KmYmN7FcuqZ26dDeXKhYQIpFItgZB8IAPPTUqFkIho5UxxTnOg_xOY8oAwl-afo5YCPWea48rvH666z3WIpMUgs5c/w400-h69/Figure-5%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-5:</u></b><span style="text-align: justify;"> I've reproduced Figure-2 to highlight the repetitive pattern of "group beating" in today's rhythm (<i>See text</i>).</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;">Knowing (<i>from Figure-4</i>) where each of the underlying regular P waves are located — allowed me to focus on the 2nd P wave in each group — which I've highlighted with <i>PINK</i> arrows in <b><u>Figure-6</u></b>. These <i>PINK</i> arrow P waves are each conducting the 2nd QRS complex in each group of beats <b>(</b>ie, <i>PINK arrow P waves are conducting beats #2,6,10 and 14</i><b>)</b>.</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Note that the PR interval of each <i>PINK</i> arrow P wave is <i>longer</i> than the PR interval before the 1st beat in each group (<i>highlighted by each RED arrow P wave</i>).</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6fZSZNHBDLKZeKilZbOVWLXpWOAGrlxKMhEuIV3c4ll8Fa2cC4a56cP87I8fN-aWBppRUJLZDEidjmPssCIO4D6vX1JSMNnip-K7yFHifYajzkPzF1Y2n8Q645Nc0SgCDQorNBahqSdOw-DFJuQPabqbpGEUpQHYXHzKoZg_OTGeWRXMkAoHqXpQypNI/s3524/Figure-6%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="620" data-original-width="3524" height="70" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj6fZSZNHBDLKZeKilZbOVWLXpWOAGrlxKMhEuIV3c4ll8Fa2cC4a56cP87I8fN-aWBppRUJLZDEidjmPssCIO4D6vX1JSMNnip-K7yFHifYajzkPzF1Y2n8Q645Nc0SgCDQorNBahqSdOw-DFJuQPabqbpGEUpQHYXHzKoZg_OTGeWRXMkAoHqXpQypNI/w400-h70/Figure-6%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-6:</u></b><span style="text-align: justify;"> I've highlighted the 2nd P wave in each group with a <i>PINK</i> arrow.</span></span></td></tr></tbody></table><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Next, in <b><u>Figure-7</u></b> — I focused on the 3rd and 4th P waves in each group <b>(</b><i>highlighted by light and dark BLUE arrows, respectively</i><b>)</b>.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Note progressive lengthening of the PR interval for each of the colored arrows in each of the 4 groups!</span></li></ul></div><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRF518a1_3RM2YXKxFwPAL5samITkz2Bs1p92DXLZKNZRjX9VLoX71KYjVudm6O4cRaFax0Wvi_7bVeAa2us_kGBJi2j4luAJqYjnvz5Lj6gqOkbQ8rCXumydplV3gwg0PmQuP4HKNmLpLJrbJobddUEOAuzx1V_BXnj5lYaBSVkCoGrYNPZkOiHkUATk/s3536/Figure-7%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="618" data-original-width="3536" height="70" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRF518a1_3RM2YXKxFwPAL5samITkz2Bs1p92DXLZKNZRjX9VLoX71KYjVudm6O4cRaFax0Wvi_7bVeAa2us_kGBJi2j4luAJqYjnvz5Lj6gqOkbQ8rCXumydplV3gwg0PmQuP4HKNmLpLJrbJobddUEOAuzx1V_BXnj5lYaBSVkCoGrYNPZkOiHkUATk/w400-h70/Figure-7%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-7:</u></b><span style="text-align: justify;"> I've highlighted the 3rd and 4th P waves in each group with light and dark BLUE arrows, respectively</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Finally, in <u style="font-weight: bold;">Figure-8</u> — I highlight with <i>YELLOW</i> arrows, the location of the next <i>on-time</i> P wave.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">It is these "on-time" <i>YELLOW</i> arrow P waves that represent the dropped (<i>non-conducted</i>) P wave in each of the Wenckebach cycles in today's rhythm.</span></li><li><span style="font-family: arial; font-size: medium;"><i>This is as it should be</i> with Wenckebach conduction — in that these non-conducted <i>YELLOW</i> P waves occur at the beginning of the slight pause between each group — after which the following <i>on-time</i> P wave (ie, <i>the next RED arrow P wave</i>) begins a new cycle with a shorter PR interval.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2503eTgENU5QLE25rH7e1I57FzqcPY2INlc3Uy6wMvuRCztBsYKUT0iVGVOcSTmjolcPp9zZqNV87062yVAOXb9lkyatxJREaPbdlgQlZE-Aw6ALVV3r9w2kDWRq41cfyQxsfSuNhPyxskitegEcm_Jyf2pG7MEHJj-XglDnFO6a-sNOqK6Kn6nu6iUY/s3528/Figure-8%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="622" data-original-width="3528" height="70" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2503eTgENU5QLE25rH7e1I57FzqcPY2INlc3Uy6wMvuRCztBsYKUT0iVGVOcSTmjolcPp9zZqNV87062yVAOXb9lkyatxJREaPbdlgQlZE-Aw6ALVV3r9w2kDWRq41cfyQxsfSuNhPyxskitegEcm_Jyf2pG7MEHJj-XglDnFO6a-sNOqK6Kn6nu6iUY/w400-h70/Figure-8%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-8:</u></b><span style="text-align: justify;"> <i>YELLOW</i> arrows highlight the non-conducted P wave in each group — after which the next Wenckebach cycle begins.</span></span></td></tr></tbody></table><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><span style="caret-color: rgb(5, 5, 5); color: #050505;">======================</span></span></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><b><u><i>The <span style="color: red;">L</span>addergram</i></u><i> . . .</i></b></span></div><div>The above derivation for today's rhythm is rendered easier to see in <b><u>Figure-9</u></b> by use of laddergram illustration.</div><div style="font-family: -webkit-standard;"><ul><li><span style="font-family: arial; font-size: medium;">For clarity in <u>Figure-9</u> — I've kept the coloration of arrows from Figure-8, to facilitate appreciation of progressive lengthening of each PR interval within each of the groups — until the 5th P wave in each group <b>(</b> = <i>the YELLOW arrow P waves</i><b>)</b> are non-conducted — followed at the end of each short pause, by resumption of conduction with PR interval shortening for the 1st beat in the next group <b>(</b><i>highlighted by each RED arrow P wave</i><b>)</b>.</span></li></ul></div></span></div><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiIei7CivryV6X6aO6efbt_c_65j5nRwL_9QYvqsTtsaAx1MyJWMSsTWH1zcZ_6AGUBSZh3bs4-9D1PttFDZTmdXog04lxT8CFYuf5VwGgXb3PB-2Jh45OPGxuigXbbtc2LPVxxo2rjtX90kNnpmYED8YLN2WrlwWeDqCmb_xhe_J9rLk5fjzhWHzdTGo0/s3752/Figure-9%20%20Laddergram-1%20(1-29.22-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1654" data-original-width="3752" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiIei7CivryV6X6aO6efbt_c_65j5nRwL_9QYvqsTtsaAx1MyJWMSsTWH1zcZ_6AGUBSZh3bs4-9D1PttFDZTmdXog04lxT8CFYuf5VwGgXb3PB-2Jh45OPGxuigXbbtc2LPVxxo2rjtX90kNnpmYED8YLN2WrlwWeDqCmb_xhe_J9rLk5fjzhWHzdTGo0/w400-h176/Figure-9%20%20Laddergram-1%20(1-29.22-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-9:</u></b><span style="text-align: justify;"> Laddergram illustration of today's rhythm.</span></span></td></tr></tbody></table><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">Figure-10 is what today's laddergram looks like without coloration.</span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiJw78iXcWC8PiNmLdyCjCc7AhQ0EtQHxKj5CbS5vwAUQl3b5O9j6h6iEhnAj9B-2BaTa4UoYY4A1h9vy78qXT2ybwFbW57YekoPfYnKk49uDeNhp9viqvRbTuli2EbbLsAWfLpSvVDiUj252iUONFEG-o1znKrewoJxcMUYZrRDPd5BhxC63zqi8OWbI/s3766/Figure-10%20%20Laddergram-2%20(1-29.23-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1662" data-original-width="3766" height="176" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiJw78iXcWC8PiNmLdyCjCc7AhQ0EtQHxKj5CbS5vwAUQl3b5O9j6h6iEhnAj9B-2BaTa4UoYY4A1h9vy78qXT2ybwFbW57YekoPfYnKk49uDeNhp9viqvRbTuli2EbbLsAWfLpSvVDiUj252iUONFEG-o1znKrewoJxcMUYZrRDPd5BhxC63zqi8OWbI/w400-h176/Figure-10%20%20Laddergram-2%20(1-29.23-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-10:</u></b><span style="text-align: justify;"> Final laddergram.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span><div><br /></div><div><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; font-size: large; text-align: justify;">======================</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>FINAL Thoughts on <i>Today's</i> Rhythm:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">As per my Note at the beginning of today's case — today's rhythm is a challenging one if you have not seen this entity before. But once you are aware of this arrhythmia presentation — it becomes <i>EASY</i> to recognize <i><u>within</u></i> seconds of seeing the tracing.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><b><i>Repetitive patterns are <u>unlikely</u> to be due to chance!</i></b> Cement this concept in your mind by going back to the original tracing <b>(</b><i>which is why I once again show </i><u style="font-weight: bold;">Figure-1</u> <i>below, without any P waves labeled</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">As you now take <i>another LOOK</i> at this initial tracing — Isn't it now easier to appreciate <u style="font-style: italic;">group</u> beating with a <i>repetitive</i> pattern of similar intervals — in which each of the short pauses are terminated by <i>easily-identifiable</i> P waves with the same PR interval before beats #1,5,9 and 13?</span></li><li><span style="font-family: arial; font-size: medium;">IF you used <b><i>calipers</i></b> to facilitate recognizing these relationships — <i>Wasn't it EASY to establish <u>within</u> seconds these similarities in intervals?</i></span></li><li><br /></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">BOTTOM Line:</u> Once you recognize that today's rhythm is supraventricular — with <i><u>group</u></i> beating — and with fast, <i>regular</i>ly-occurring P waves — that show clear conduction of the 1st P wave at the end of each pause — you have essentially established that the rhythm is <b>ATach</b> with <b><i>Wenckebach</i> conduction</b>.</span></li><li><span style="font-family: arial; font-size: medium;">Today's rhythm is <i><u>not</u></i> complete AV block — because complete ( = <i>3rd-degree</i>) AV block is most often associated with a <i>regular</i> escape rhythm — and the ventricular rhythm in <u>Figure-1</u> is clearly <i>not</i> regular!</span></li><li><span style="font-family: arial; font-size: medium;">The "good news" — is that most of the time when ATach is associated with the group beating pattern of 2nd-degree AV Wenckebach — the conduction defect usually resolves once the ATach is controlled.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: -webkit-standard; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9zo-mBKD9QHHStUDAd4vew9LGKmkpfwxqTP4jTAF3H-NXjVJhHm13Z6XrjnCs9bSXDsOo-_Xp_RvM3vrzFB1nIDF-KHzkjJKpfQfIjVG8A-oK04IlI8K2L8hkxNCk-jHPmOPq-vmSbDifMlXMc2StjCPmJqrn_gSGSs5qsmOqtP3YzWYBRRu_tlM7Poo/s3528/Figure-1%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="608" data-original-width="3528" height="69" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9zo-mBKD9QHHStUDAd4vew9LGKmkpfwxqTP4jTAF3H-NXjVJhHm13Z6XrjnCs9bSXDsOo-_Xp_RvM3vrzFB1nIDF-KHzkjJKpfQfIjVG8A-oK04IlI8K2L8hkxNCk-jHPmOPq-vmSbDifMlXMc2StjCPmJqrn_gSGSs5qsmOqtP3YzWYBRRu_tlM7Poo/w400-h69/Figure-1%20%20Leads%20I,II%20(1-29.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-1:</u></b><span style="text-align: justify;"> <i>Take another LOOK at today's rhythm!</i></span></span></td></tr></tbody></table><br /><span style="font-family: arial; font-size: medium;"></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div><br /></div></span></div><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: left;"><div style="text-align: justify;"><span style="color: #333333; font-family: arial; font-size: medium;">==================================</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation </span>for the case and this tracing that was anonymously sent to me for my opinion.</span></div><div style="text-align: justify;"><span style="color: #333333; font-family: arial; font-size: medium; text-align: left;">==================================</span></div></div><div style="text-align: left;"><span style="color: #333333; font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: left;"><span style="color: #333333; font-family: arial; font-size: medium;"><div style="caret-color: rgb(0, 0, 0); color: black; text-align: justify;"><span><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></div><div style="caret-color: rgb(0, 0, 0); color: black; text-align: justify;"><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — reviews the <b>Ps, Qs & 3R Approach (</b><i>Listen to <b><u>Audio</u></b> Pearl #3 in this post</i><b>)</b>.</span></li><li style="text-align: justify;"><span><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> draw <b>Laddergram</b></span></span></span><span><span><b>s</b></span></span><span><b> </b></span><span><b>(</b><i>w</i></span><i>ith LINKS to more than 90 laddergram cases — many with step-by-step sequential illustration</i><b>)</b><span>.</span></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-267-75-group-beating-and.html" target="_blank">ECG Blog #267</a></b> — Reviews with <b><i>step-by-step</i></b> <b><u>laddergrams</u></b>, the derivation of a case of Mobitz I with more than a single possible explanation.</li><li style="text-align: justify;"><span><span><br /></span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/04/blog-210-ecg-mp-27-regular-wct-how-fast.html" target="_blank">ECG Blog #210</a></b> — for review of the <b><i>Every-Other-Beat </i>Method</b> for rapi</span>d estimation of heart rate <b>(</b><i>See <b><u>Video</u> </b>Pearl #27 in this post</i><b>)</b>.</li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-229-45-is-this-vt-or-something.html" target="_blank">ECG Blog #229</a></b> — reviews distinction between <b>AFlutter</b> <i><u>vs</u></i> <b>ATach</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">The <b><a href="https://hqmeded-ecg.blogspot.com/2019/11/what-is-this-regular-svt.html" target="_blank">November 12, 2019</a> post</b> in Dr. Smith's ECG Blog — in which I review my approach to a <b><i>Regular </i>SVT rhythm</b>.</span></li></ul><div><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-261-51a-how-many-p-waves.html" target="_blank">ECG Blog #261</a> </b>and <b><a href="https://ecg-interpretation.blogspot.com/2023/03/ecg-blog-370-post-arrest-tachycardia.html" target="_blank">ECG Blog #370</a> </b>— for additional examples of <b>ATach</b> with <b><i>Wenckebach</i></b> <b>conduction</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" target="_blank">ECG Blog #192</a></b> — The <b>3 <i><u>Causes</u></i></b> of <b>AV Dissociation</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-191-ecg-mp-8-is-av-block.html" target="_blank">ECG Blog #191</a></b> — Reviews the difference between <b>AV Dissociation</b> <u>vs</u> <b><i>Complete</i> AV Block</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2023/08/ecg-blog-389-quote-from-sherlock-holmes.html" target="_blank">ECG Blog #389</a></b> — <b><a href="https://ecg-interpretation.blogspot.com/2023/04/ecg-blog-373-86yo-and-this-rhythm.html" target="_blank">ECG Blog #373</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-344-mobitz-i-mobitz-ii-or.html" target="_blank">ECG Blog #344</a></b> — for review of some cases that illustrate <b><i>"AV block problem-solving"</i></b>.</li></ul></div></div></span></div></span></div><div><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMGfPNOl6awsiXnccY-BJTyL33304SbJxyrTAuBY77ThO8adfpH5MvR_zaU-iNxSjgMi9phUVqPIDEu5EremSYoRMJCgARN2_3UmVpy0wSmI6PCyGZ_dTZaHRvO9x7uedTSyjGB-8-7Aw/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhMGfPNOl6awsiXnccY-BJTyL33304SbJxyrTAuBY77ThO8adfpH5MvR_zaU-iNxSjgMi9phUVqPIDEu5EremSYoRMJCgARN2_3UmVpy0wSmI6PCyGZ_dTZaHRvO9x7uedTSyjGB-8-7Aw/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></span></a></div><div class="separator" style="clear: both; text-align: right;"><span style="font-family: arial; font-size: medium;"><br /></span></div></div><p class="MsoNormal"><br /></p><div><div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #050505; font-family: arial; font-size: medium;"><br /></span></p></div></div></div><br />ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-39380837638624621502024-03-02T03:55:00.026-05:002024-03-06T16:23:12.773-05:00ECG Blog #419 — The Cause of ECG #1?<span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;">I was sent the 2 ECGs shown in <u style="font-weight: bold;">Figure-1</u> — which were recorded from an elderly man whose heart beat "has been irregular for years". No clear history for recent chest pain — but the patient "has not been well" for the previous week. <i>Regarding the 2 ECGs in</i> <u>Figure-1</u>: </div><div style="text-align: justify;"><ul><li><u style="font-weight: bold;">ECG #1</u> is the initial tracing obtained at the scene by the EMS (<i><u>E</u>mergency <u>M</u>edical <u>S</u>ystems</i>) team — in association with an alert but markedly <i>hypotensive</i> patient.</li><li><u style="font-weight: bold;">ECG #2</u> was recorded a short while after <u>ECG #1</u> by the EMS team — but <i>before</i> any treatment other than ASA was given. As might be imagined — the patient suddenly "felt much better".</li></ul></div></span><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u>QUESTIONS:</u></b></span></div><div><ul style="text-align: left;"><li><span style="font-family: arial; font-size: medium;"><i>How would YOU interpret</i> these 2 ECGs?</span></li><li><span style="font-family: arial; font-size: medium;"> — <b><i>How might</i> <u>ECG #2</u> be <i>related</i> to <u>ECG #1</u>?</b></span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5Za_6F5e2PL8zGf-Qhqz2zgu46ZLzW_oaQBu9pkkaOVC1Fl3RLPsrItyHwGxQmVOaH27hDUE6GWwYEmK7F8v8cNFcAQjVfqyKvCIFHLDPUr_Uk6LbZevAuzkKGUnkoMZQePtfQWj64LkSvwAkfFniUrBMhnZR8YP_AfEeXTWMa2Gjv3OVcBLtjRczyw4/s3280/Figure-1%20%20ECGs-1,2%20(2-22.21-2024)-USE%20copy.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2756" data-original-width="3280" height="336" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5Za_6F5e2PL8zGf-Qhqz2zgu46ZLzW_oaQBu9pkkaOVC1Fl3RLPsrItyHwGxQmVOaH27hDUE6GWwYEmK7F8v8cNFcAQjVfqyKvCIFHLDPUr_Uk6LbZevAuzkKGUnkoMZQePtfQWj64LkSvwAkfFniUrBMhnZR8YP_AfEeXTWMa2Gjv3OVcBLtjRczyw4/w400-h336/Figure-1%20%20ECGs-1,2%20(2-22.21-2024)-USE%20copy.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><span><b style="text-align: start;"><u>Figure-1:</u></b><span style="text-align: start;"> </span></span><span style="text-align: start;">The 2 ECGs in today's case.</span><span><span style="text-align: start;"> </span></span><b>(</b><i>To improve visualization — I've digitized the original ECG using</i><span> </span><b><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span>. </span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><br /></span><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>MY Thoughts</i> on the 2 ECGs in Figure-1:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">Even without a long lead rhythm strip — it is easy to understand why today's patient was markedly <u style="font-style: italic;">hypotensive</u> in association with <u style="font-weight: bold;">ECG #1</u>.</span></span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><b><span style="font-family: arial; text-align: left;">Atrial activity </span><u style="font-family: arial; font-style: italic; text-align: left;">is</u></b><span style="font-family: arial; text-align: left;"><b> present</b> in </span><u style="font-family: arial; text-align: left;">ECG #1</u><span style="font-family: arial; text-align: left;"> — in the form of seemingly <i>regular</i> upright<b> P waves</b> in each of the inferior leads — at a <i>regular</i> rate of <b>~115/minute</b>. </span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">I suspect that <u style="font-style: italic;">none</u> of the P waves in ECG #1 are conducted.</span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">Detection of atrial activity is much more difficult in the chest leads due to a large amount of <b><i>baseline</i></b> <b>artifact </b>— although evidence of atrial activity at a similar rate <u><i>is</i></u> seen toward the end of lead V1.</span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">The above said — <i>intermittent</i> ventricular complexes of <i>varying</i> morphologies are seen <b>(</b><i>albeit with much distortion from artifact</i><b>)</b>.</span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">The <i><u><b>longest</b></u></i> <b>pause</b> occurs in <i>simultaneously-recorded</i> leads aVR,aVL,aVF — with <i><u>no</u></i> ventricular complex seen after the 1st beat in these leads <i><u>until</u></i> the lead change to V1,V2,V3 occurs <b>(</b>ie, <i>almost 12 large boxes = <b>2.4 seconds later</b></i><b>)</b>. We have <i>no idea</i> how long the pause was before the 1st beat in ECG #1 was recorded.</span></span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><u style="font-weight: bold;"><i><span style="color: red;">C</span>linical</i> <span style="color: red;">I</span>MPRESSION:</u> I would interpret <u>ECG #1</u> as suggestive of <b>near <i>ventricular</i> standstill </b>— with underlying atrial tachycardia, extended pauses, and <i><u>no</u></i> reliable ventricular escape focus. <i>This is often a pre-lethal rhythm</i>.</span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><br /></span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>1:</u> The rhythm in <u>ECG #1</u> is <i>more</i> than just "complete AV block". This is because in addition to <i>no</i> conduction of any of the sinus P waves — the presence of a fairly regular <i>escape</i> pacemaker that is usually seen with complete AV block is absent. Instead, we see extended pauses that are intermittently interrupted by irregular (<i>and unreliable</i>) ventricular complexes arising from different ventricular sites.</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i>Before any treatment</i> — <u style="font-weight: bold;">ECG #2</u> was recorded:</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial;"><span style="font-size: medium;"><b>Normal <i><u>sinus</u></i> rhythm</b> <i>has <u>spontaneously</u> returned! </i>Interestingly — the rate (<i>and morphology</i>) of sinus P waves is virtually unchanged with respect to the unconducted P waves that were seen in <u>ECG #1,</u> the difference being that there is now 1:1 conduction of sinus impulses with a normal PR interval!</span></span></li></ul><span style="font-size: medium;"><span style="font-family: arial;"><div style="text-align: justify;"><span style="font-family: arial;"><br /></span></div><u style="font-weight: bold;">NOTE:</u> The <b>QRS complex</b> of conducted beats in <u>ECG #2</u> is <b><i><u>wide</u></i></b>. QRS morphology is interesting in that it resembles <b>RBBB (</b><i><u>R</u>ight <u>B</u>undle <u>B</u>ranch <u>B</u>lock</i><b>) conduction</b> in the <i><u>chest</u></i> leads — but <b>LBBB (</b><i><u>L</u>eft <u>B</u>undle <u>B</u>ranch <u>B</u>lock</i><b>) conduction</b> with marked <b><u style="font-style: italic;">left</u> axis </b>in the <i><u>limb</u></i> leads. </span><br /></span><ul><li><span style="font-family: arial;"><span style="font-size: medium;">The tall R wave (<i>qR morphology</i>) in lead V1 of <u>ECG #2</u> — in association with a fairly wide terminal S wave in lead V6 — suggests <b>RBBB conduction</b>.</span></span></li><li><span style="font-family: arial;"><span style="font-size: medium;">The predominantly upright widened QRS complexes in leads I and aVL of <u>ECG #2</u> — suggests <b>LBBB conduction</b> — with the predominantly negative QRS complexes in each of the inferior leads indicative of marked <b>LAD (</b><i><u>L</u>eft <u>A</u>xis <u>D</u>eviation</i><b>)</b>.</span></span></li></ul></div><div><span style="font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>2:</u> As described in <b><a href="https://ecg-interpretation.blogspot.com/2023/09/ecg-blog-394-is-qrs-morphology-disguised.html " target="_blank">ECG Blog #394</a></b> — QRS widening in the presence of sinus rhythm, in which QRS morphology is consistent with <b>RBBB conduction</b> in the <i><u>chest</u></i> leads — but <b>LBBB conduction</b> in the <i><u>limb</u></i> leads <b>(</b><i>especially with a </i><b><i>leftward </i>axis</b><b>)</b> — suggests the entity known as <b><u>MBBB</u> (</b><i><u>M</u>asquerading <u>B</u>undle <u>B</u>ranch <u>B</u>lock</i><b>)</b>. This is precisely the picture of the QRS morphology that we see in <u>ECG #2</u>.</span></div><div><span style="font-size: medium;"><span style="font-family: arial;"><div style="font-family: -webkit-standard; text-align: justify;"><ul><li><span style="font-family: arial;">I review my </span><i style="font-family: arial;">user-friendly</i><span style="font-family: arial;"> approach to the ECG diagnosis of the </span><b style="font-family: arial;">Bundle Branch Blocks </b><span style="font-family: arial;">in </span><b style="font-family: arial;"><a href="https://ecg-interpretation.blogspot.com/2022/02/ecg-blog-282-lbbb-and-sgarbossa-lvh-mi.html" target="_blank">ECG Blog #282</a></b><span style="font-family: arial;"> — and to </span><b style="font-family: arial;"><i>Hemiblocks</i></b><span style="font-family: arial;"> and </span><b style="font-family: arial;"><i>Bifascicular</i></b><span style="font-family: arial;"> </span><b style="font-family: arial;">Blocks</b><span style="font-family: arial;"> in </span><b style="font-family: arial;"><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-203-ecg-mp-2021-axis.html" target="_blank">ECG Blog #203</a></b><span style="font-family: arial;">. In brief — the 3 </span><i style="font-family: arial;">KEY</i><span style="font-family: arial;"> leads that allow accurate diagnosis of RBBB and LBBB </span><i style="font-family: arial;"><u>within</u></i><span style="font-family: arial;"> seconds (!) — are </span><i style="font-family: arial;">right-sided</i><span style="font-family: arial;"> </span><b style="font-family: arial;">lead V1</b><span style="font-family: arial;"> and </span><i style="font-family: arial;">left-sided</i><span style="font-family: arial;"> </span><b style="font-family: arial;">leads I</b><span style="font-family: arial;"> and </span><b style="font-family: arial;">V6</b><span style="font-family: arial;">.</span></li><li><span style="font-family: arial;"><span style="font-size: medium;">Supraventricular conduction defects <i><u>not</u></i> consistent with either RBBB or LBBB in <i><u>all</u></i> 3 of these key leads are most easily classified as <b>IVCD (</b><i><u>I</u>ntra<u>V</u>entricular <u>C</u>onduction <u>D</u>efect</i><b>)</b> — with this category representing the "end result" of a number of different pathophysiologic processes.</span></span></li><li><span style="font-family: arial;"><span style="font-size: medium;"><br /></span></span></li><li><span style="font-family: arial;"><span style="font-size: medium;"><b><u><span style="color: red;">M</span>BBB</u></b> is a <b><i>special</i> type</b> of <b>IVCD</b> that although uncommon, is important to recognize because it identifies a group of patients with: <b>i<span style="color: red;">)</span></b> Very severe underlying heart disease; <b>ii<span style="color: red;">)</span></b> A much higher predisposition for developing complete AV block (<i>and needing a pacemaker</i>); <u>and</u>, <b>iii<span style="color: red;">)</span> </b>An extremely poor longterm prognosis.</span></span></li><li><b style="font-family: arial;"><u><br /></u></b></li><li><b style="font-family: arial;"><u>NOTE:</u></b><span style="font-family: arial;"> Variations on this above "theme" of MBBB are common. Thus, the S wave that is typically associated with RBBB patterns in lateral chest leads V5,V6 may or may not be present. In the limb leads, rather than a strict LBBB pattern — more of an </span><b style="font-family: arial;"><i>extreme</i> LAHB (</b><i style="font-family: arial;"><u>L</u>eft <u>A</u>nterior <u>H</u>emi<u>B</u>lock</i><b style="font-family: arial;">) pattern</b><span style="font-family: arial;"> may be seen </span><b style="font-family: arial;">(</b><span style="font-family: arial;">ie, </span><i style="font-family: arial;">with wide and predominantly [if not totally] negative QRS complexes in the inferior leads — and with a smaller [blunted] terminal s wave in leads I and aVL</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></li></ul></div><div style="font-family: -webkit-standard; text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><b><u><br /></u></b></span></span></div><div style="font-family: -webkit-standard; text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><b><u>PEARL <span style="color: red;">#</span>3:</u></b> Knowing the <b><i><u>clinical</u></i></b> <b>history</b> may aid in recognition of IVCD patterns that are consistent with <b>MBBB</b> <b>(</b>ie,<i> if the patient has a known history of severe, underlying heart disease</i><b>)</b>. </span></span><br /><ul><li><span style="font-family: arial;">Distinction from simple <b><i><u>bifascicular</u></i></b> <b>block (</b>ie, <i>with </i><b><i>RBBB/LAHB</i>)</b> — may be facilitated by seeing one or more of the following: <b>i<span style="color: red;">)</span> </b>More of a </span><span style="font-family: arial;"><i>monomorphic</i> upright QRS in lead V1 <b>(</b><i>which lacks the neatly defined, triphasic rsR' with taller right "rabbit ear" seen with typical RBBB</i><b>)</b>; <b>ii<span style="color: red;">)</span> </b>Lack of a wide terminal S wave in lateral chest lead V6; <b>iii<span style="color: red;">)</span></b> Seeing an all-positive (<i>or at least predominantly positive</i>) widened QRS in leads I <i>and/or</i> aVL, with <i>no more</i> than a tiny, narrow s wave in these leads; <u>and</u>/<u>or</u>, <b>iv<span style="color: red;">)</span> </b>Seeing widened, all-negative (<i>or almost all-negative</i>) QRS complexes in the inferior leads.</span></li></ul></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><b><u><i><br /></i></u></b></span></div><div style="font-family: -webkit-standard; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>What About Today's</i> ECGs?</u></b></span></div><div style="font-family: -webkit-standard; text-align: justify;"><span style="font-family: arial; font-size: medium;">Although details of the history of today's patient are lacking — the patient is elderly — he has had "an irregular heart beat for years" — and his <b><i><u>initial</u></i></b> <b>ECG</b> on EMS arrival <b>(</b> = <i>ECG #1</i><b>)</b> clearly suggests advanced conduction system disease with a potentially lethal rhythm were it not for spontaneous conversion to the tracing shown in <u>ECG #2</u>.</span></div><div style="text-align: justify;"><ul><li>In this clinical context — findings in <u>ECG #2</u> are clearly consistent with <b><i><u>masquerading</u></i></b> <b>BBB</b>. </li><li><br /></li><li>A <b><i>permanent</i></b> <b>pacemaker</b> is needed. </li></ul></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; font-family: -webkit-standard; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div><br /></div></span></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="font-family: -webkit-standard;"><div style="text-align: justify;"><span style="color: #333333; font-family: arial; font-size: medium;">==================================</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Max-Gordon-Hall</span> (<i>from </i><span style="text-align: start;"><span style="color: #1c1e21;"><i>Batlow, New South Wales, Australia</i></span></span>) for the case and this tracing.</span></div><div style="text-align: justify;"><span style="color: #333333; font-family: arial; font-size: medium; text-align: left;">==================================</span></div></div><div style="font-family: -webkit-standard;"><span style="color: #333333; font-family: arial; font-size: medium;"><br /></span></div><div style="font-family: -webkit-standard;"><span style="color: #333333; font-family: arial; font-size: medium;"><div style="caret-color: rgb(0, 0, 0); color: black; text-align: justify;"><span><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></div><div style="caret-color: rgb(0, 0, 0); color: black; text-align: justify;"><p class="MsoNormal"></p><ul><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span style="color: red;">S</span>ystematic</i></b> <b><span style="color: red;">A</span>pproach</b> to 12-lead ECG Interpretation. </span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2022/02/ecg-blog-282-lbbb-and-sgarbossa-lvh-mi.html" target="_blank">ECG Blog #282</a></b> — reviews a <i>user-friendly</i> approach to the ECG diagnosis of the <b>Bundle Branch Blocks (</b><i>RBBB, LBBB and IVCD</i><b>)</b>.</span></li><li style="text-align: justify;"><span><br /></span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-203-ecg-mp-2021-axis.html" target="_blank">ECG Blog #203</a></b> — reviews ECG diagnosis of Axis, <b><i>Hemiblocks</i></b> and <b><i>Bifascicular</i></b> <b>Blocks</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2023/09/ecg-blog-394-is-qrs-morphology-disguised.html" target="_blank">ECG Blog #394</a></b> — reviews another case of <b><i>Masquerading</i></b> <b>BBB</b>.</span></li></ul></div></span></div></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; font-family: -webkit-standard; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div><br /></div></span></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div style="background-color: white;"><div><span><span style="caret-color: rgb(255, 0, 0); color: red; font-family: arial; font-size: medium;">=======================</span></span></div><p style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><span style="color: #454545;"><b><i>ADDENDUM</i> (</b><i>3/6</i></span><span style="color: #454545;"><i>/2024</i><b>): </b></span></span></p><div><span style="color: red; font-family: arial; font-size: medium;">=======================</span></div><div>In follow-up to the Comment I have just received from <b>H.S.Cho</b> — I would expand on my description of the cardiac rhythm in <u style="font-weight: bold;">ECG #1</u> from today's case.</div><div><ul><li>Given the history in today's case <b>(</b>ie, <i>Sudden onset of the rhythm seen in ECG #1 — that within a minute spontaneously resolved</i><b>)</b> — Rather than <i>"near ventricular standstill" —</i> this rhythm is best described as <b>PD-PAVB (</b><i><u>P</u>ause-<u>D</u>ependent <u>P</u>aroxysmal <u>A</u>trio<u>V</u>entricular <u>B</u>lock</i><b>)</b>.</li><li><br /></li><li>For clarity — I have reproduced <u><b>Figure-1</b></u> from today's case.</li></ul><div style="text-align: center;"><br /></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: auto; margin-right: auto;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5Za_6F5e2PL8zGf-Qhqz2zgu46ZLzW_oaQBu9pkkaOVC1Fl3RLPsrItyHwGxQmVOaH27hDUE6GWwYEmK7F8v8cNFcAQjVfqyKvCIFHLDPUr_Uk6LbZevAuzkKGUnkoMZQePtfQWj64LkSvwAkfFniUrBMhnZR8YP_AfEeXTWMa2Gjv3OVcBLtjRczyw4/s3280/Figure-1%20%20ECGs-1,2%20(2-22.21-2024)-USE%20copy.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2756" data-original-width="3280" height="336" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi5Za_6F5e2PL8zGf-Qhqz2zgu46ZLzW_oaQBu9pkkaOVC1Fl3RLPsrItyHwGxQmVOaH27hDUE6GWwYEmK7F8v8cNFcAQjVfqyKvCIFHLDPUr_Uk6LbZevAuzkKGUnkoMZQePtfQWj64LkSvwAkfFniUrBMhnZR8YP_AfEeXTWMa2Gjv3OVcBLtjRczyw4/w400-h336/Figure-1%20%20ECGs-1,2%20(2-22.21-2024)-USE%20copy.png" width="400" /></a></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><span><b style="text-align: start;"><u>Figure-1:</u></b><span style="text-align: start;"> </span></span><span style="text-align: start;">The 2 ECGs in today's case</span><span>. </span></span></div><div><br /></div><div><br /></div><div><b><u>Paroxysmal <i>AtrioVentricular</i> Block</u> (</b><i>PAVB</i><b>):</b></div><div>As described by Bansal et al (<b><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6898553/" target="_blank">J Arrhythmia 35:870-872, 2019</a></b>) and Bosah et al (<b><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9391957/" target="_blank">Cureus 14[7]: e27092, 2022</a></b>) — the entity known as PAVB is a potential cause of syncope that is easily overlooked and which is potentially lethal (<i>probably more often than is commonly realized</i>).</div><div><ul><li><b><u>PAVB</u></b> is characterized by the sudden, unexpected onset of <i>complete</i> AV block with <i>delayed</i> ventricular escape — therefore resulting in a <i>prolonged</i> period <i><u>without</u></i> any QRS on ECG. Prior to the prolonged pause — the patient manifests 1:1 AV conduction <i>without</i> other evidence of AV block (<i>which is why onset of PAVB is typically so unsuspected!</i>).</li><li>Because of its totally unexpected onset and propensity to result in sudden death — PAVB is difficult to document and significantly underdiagnosed.</li><li>Three mechanisms for producing PAVB have been described: <b>i<span style="color: red;">)</span></b> <b>Vagally mediated (</b>ie, <i><u>Vagotonic</u> Block — as described in </i><b><a href="https://ecg-interpretation.blogspot.com/2013/02/ecg-interpretation-review-61-av-block.html" target="_blank">ECG Blog #61</a></b>, <i>with the references listed at the end this Blog post citing instances of transient asystole from excessive vagal tone!</i><b>)</b>; <b>ii<span style="color: red;">)</span> Intrinsic (</b><i>Phase 4 = pause- or bradycardic-dependent</i><b>) PAVB</b>; — <u>and</u>, <b>iii<span style="color: red;">)</span> Idiopathic</b>.</li></ul></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><b>i<span style="color: red;">)</span> <i><u>Vagotonic</u></i> AV Block:</b></span></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;">This form of PAVB is potentially benign when it results from a transient profound surge of parasympathetic tone in an otherwise healthy individual <b>(</b><i>as might occur with an episode of severe vomiting; a fit of severe coughing; vasovagal reaction from a blood draw</i><b>)</b>.</span></div><div><ul><li>The problem with vagotonic PAVB is localized to <u style="font-style: italic;">within</u> the AV Node.</li><li>There will often be a "prodome" of diaphoresis, nausea, dizziness — with the patient aware of imminent fainting.</li><li><br /></li><li><b><u><i>Characteristic</i> ECG findings</u></b> of <b><i>vagotonic</i> PAVB</b> include progressive sinus rate slowing — often associated with an increasing PR interval and a narrow-QRS escape focus — followed by recovery with progressive return to a normal sinus rate and normal PR interval.</li></ul><div><br /></div><div><b>ii<span style="color: red;">)</span> <i><u>Intrinsic</u></i> PAVB:</b></div><div>Several names have been attached to this mechanism of PAVB — including most commonly "Phase 4 AV block" <i>and/or</i> <b>PD-PAVB (</b><i><u>P</u>ause-<u>D</u>ependent <u>P</u>aroxysmal <u>A</u>trio<u>V</u>entricular <u>B</u>lock</i><b>)</b>.</div><div><ul><li>PD-PAVB is the most likely mechanism for the cardiac rhythm in <u>ECG #1</u> from today's case. The underlying pathology is <b><i>severe</i> His-Purkinje System disease</b> <b>(</b><i>strongly suggested by the presence of <b>MBBB</b> in </i><u>ECG #2</u><i> of today's case</i><b>)</b>. This form of PD-PAVB is likely to be fatal <i><u>unless</u></i> the patient receives a <b><i>permanent</i></b> <b>pacemaker</b>.</li><li>The interesting pathophysiology of PD-PAVB results from chance occurrence of an "appropriately-timed" PAC or PVC that partially depolarizes the <b><i>diseased</i></b> <b>HPS (</b><i>His-Purkinje System</i><b>)</b> at a specific point in the cycle that renders the poorly-functioning HPS unable to complete depolarization. The resultant prolonged pause in ventricular depolarization may only resolve if another "appropriately-timed" PAC or PVC occurs at the precise point needed to "reset" the HPS depolarization cycle <b>(</b><i>which presumably explains why the patient in today's case spontaneously recovered</i><b>)</b>.</li><li>Of note — although severe underlying HPS disease is evident from the MBBB seen in <u>ECG #1</u> of today's case — up to 1/3 of patients with PD-PAVB do <u style="font-style: italic;">not</u> show evidence of conduction defects on ECG, thereby complicating documentation of this diagnosis.</li><li><br /></li><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>4:</u> In addition to seeing MBBB in <u>ECG #2</u> — the fact that <b>the atrial rate remains the same in <u style="font-style: italic;">both</u> ECG #1 and ECG #2</b> is yet one more reason why the rhythm in ECG #1 does <u style="font-style: italic;">not</u> represent simple vagotonic PAVB.</li></ul><div><br /></div></div><div><b>iii<span style="color: red;">)</span> <i><u>Idiopathic</u></i> PAVB: </b></div><div>This is the most recently described form of PAVB — in which findings are not consistent with either of the other 2 forms.</div><div><ul><li>The baseline ECG before <i>idiopathic</i> PAVB tends to be normal.</li><li>No "trigger" for PAVB is evident (ie, <i>no source of excessive vagal tone — and no precipitating PACs/PVCs are seen</i>).</li></ul></div></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><span>=====================================</span></span></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><span><b><u>NOTE:</u></b> The conduction disturbance shown in <u>ECG #1</u> from today's case differs from that shown in <b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-342-this-is-12-lead-ecg.html" target="_blank">ECG Blog #342</a></b> — in which the initial rhythm was AFib (ie, <i><u>no</u> P waves present for the first 6 beats in this tracing</i>) — followed by a prolonged flat line pause (<i>nearly 5 seconds in duration</i>) — until finally a QRS complex preceded by a P wave (<i>that may or may not have been conducting</i>) was seen.</span></span></div><div><ul><li>Whether the prolonged flat line pause in this Blog #342 example represents another variation of PD-PAVB due to severe underlying disease of the His-Purkinje System — or reflects severe SA Node disease (ie, <i><u>S</u>ick <u>S</u>inus <u>S</u>yndrome</i>) — or most likely represents some combination of the two, is uncertain from the single ECG I was provided with.</li><li>That said — the <u style="font-weight: bold;">BOTTOM</u> <u style="font-weight: bold;">Line</u> remains the same, namely that assuming nothing "fixable" is found — <b><i>permanent</i></b> <b>pacing</b> will be needed.</li></ul></div></div></div></div><div style="text-align: justify;"><div style="text-align: left;"><div style="text-align: center;"><br /></div><div style="text-align: justify;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPC82c_PoQRI5tFhXopYT4F_BP0THO2jKN01XLg3VEhs2qdQK3tRDl1NOKpLcr49cTKvVyxnHGv8E1hBQdHTlMUYqbEONedcPcn19VbY5PHrVV_pcEjtmf-_28SyGCP6A6dn0vEZb1vcg/s1600/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="12" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjPC82c_PoQRI5tFhXopYT4F_BP0THO2jKN01XLg3VEhs2qdQK3tRDl1NOKpLcr49cTKvVyxnHGv8E1hBQdHTlMUYqbEONedcPcn19VbY5PHrVV_pcEjtmf-_28SyGCP6A6dn0vEZb1vcg/s320/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="320" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"> </div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div><br /></div></div></div></div></span></div><div><br /></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com3tag:blogger.com,1999:blog-3364570834099131201.post-40704258899250055712024-02-24T00:03:00.000-05:002024-02-24T00:03:17.259-05:00ECG Blog #418 — A Single Lead Tells the Tale ...<span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;">The ECG in <u style="font-weight: bold;">Figure-1</u> was obtained from a previously healthy man in his 40s — who presented to the ED (<i><u>E</u>mergency <u>D</u>epartment</i>) with <b><i>new-onset</i> CP (</b><i><u>C</u>hest <u>P</u>ain</i><b>)</b> that awakened him from sleep.</div><div style="text-align: justify;"><ul><li><u style="font-weight: bold;">ECG #1</u> was recorded ~90 minutes after the patient was awakened from sleep. <i>He was still having CP</i>. </li></ul></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>QUESTIONS:</u></b></div><div style="text-align: justify;"><ul><li>In view of this history — <i>How would YOU interpret </i>the ECG in <u>Figure-1</u>?</li><li>Does a <i>single</i> lead “tell the tale”?</li></ul></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVK6vTsiH7dhLMwsOYPh-_aIEsMRlX9qv09oAb7goToqfFzlpHEHTKoo-yjAzVv8FLBz2kTy1_fkan3iwH2f3V-sOe0oYXPHl3Yh4t9KcXGWnU2F5urZRzsDA_FnD_zLyONiM78s7ICKeeO3OUozKLDF3PlkQlu5wEWSV5dqjJ5c3lRrPHW8F94Kdu4BM/s3790/Figure-1%20%20ECG-1%20%20(2-6.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1748" data-original-width="3790" height="184" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVK6vTsiH7dhLMwsOYPh-_aIEsMRlX9qv09oAb7goToqfFzlpHEHTKoo-yjAzVv8FLBz2kTy1_fkan3iwH2f3V-sOe0oYXPHl3Yh4t9KcXGWnU2F5urZRzsDA_FnD_zLyONiM78s7ICKeeO3OUozKLDF3PlkQlu5wEWSV5dqjJ5c3lRrPHW8F94Kdu4BM/w400-h184/Figure-1%20%20ECG-1%20%20(2-6.21-2024)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span><b style="text-align: start;"><u>Figure-1:</u></b><span style="text-align: start;"> </span></span><span style="text-align: start;">The <b><i><u>initial</u></i></b> <b>ECG</b> in today's case.</span><span><span style="text-align: start;"> </span></span><b>(</b><i>To improve visualization — I've digitized the original ECG using</i><span> </span><b><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span>. </span></span></td></tr></tbody></table><br /><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u><i>MY Thoughts</i> on the ECG in Figure-1:</u></b></div><div style="text-align: justify;"><span style="text-align: start;">The important points about today’s history are: </span><b style="text-align: start;">i<span style="color: red;">)</span></b><span style="text-align: start;"> That the patient is a previously healthy man in his 40s; — </span><b style="text-align: start;">ii<span style="color: red;">)</span></b><span style="text-align: start;"> That the patient was <i>awakened</i> from sleep by <i>new</i> CP; — <u>and</u>, <b>iii<span style="color: red;">)</span></b> That <i>his CP was still ongoing</i> 90 minutes after it began, at the time <u>ECG #1</u> was recorded in the ED.</span></div><div style="text-align: justify;"><ul><li><span style="text-align: start;">The ECG in </span><u style="text-align: start;">Figure-1</u><span style="text-align: start;"> shows normal sinus rhythm at ~75/minute — with normal intervals (</span><i style="text-align: start;">PR-QRS-QTc</i><span style="text-align: start;">) and axis — and no chamber enlargement.</span></li></ul></div><div style="text-align: justify;"><div style="text-align: justify;"><i>Regarding </i><b><u>Q</u>-<u>R</u>-<u>S</u>-<u>T</u> Changes:</b></div><div style="text-align: justify;"><ul><li><b style="text-align: left;"><u>Q</u> waves:</b><span style="text-align: left;"> There are <u style="font-style: italic;">no</u> Q waves. There is a <i>small-but-present</i> initial positive deflection ( = <i>r wave</i>) in lead III <b>(</b><i>I don't count as "Q waves" the initial negative deflections we see in leads aVR and V1 — since it is normal to see Q waves in these leads</i><b>)</b>.</span></li><li><span style="text-align: left;"><b><u>R</u> wave progression:</b> There are good-sized R waves beginning in lead V2 — albeit there is slight delay in transition <b>(</b><i>with the R wave becoming taller than the S wave is deep only between leads V4-to-V5</i><b>)</b>.</span></li></ul></div></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><i>What About</i></b> <b><u><span style="color: red;">S</span></u>T-<u><span style="color: red;">T</span></u> Wave Changes?</b></div><div style="text-align: justify;">As we assess today's initial ECG for ST-T wave changes — It is important to remember that this patient was previously healthy — <u>and</u> — he was <i>awakened</i> from sleep by CP that was still present 90 minutes later <b>(</b>ie, <i>at the time this initial ECG was recorded</i>!<b>)</b>.</div><div style="text-align: justify;"><ul><li>As a result — <b>We <i><u>need</u> to consider this patient</i> to be in a <i><u>higher</u>-risk</i> group</b> for having an <b><i><u>acute</u></i></b> <b>event</b>. This point emphasizes that the burden of proof falls on us as medical providers to prove that this patient is <u style="font-style: italic;">not</u> having an acute event, <i>rather than the other way around!</i></li></ul><div><b><br /></b></div><div><b>We <i><u>Need</u></i> to Remember the Following:</b></div><ul><li>Even with an <i>acute</i> event — the initial ECG may not necessarily show remarkable changes — <i><u>and</u>/<u>or</u></i> — ECG changes may be present, but subtle <b>(</b><i>and sometimes <u>only</u> recognized when compared to a prior baseline ECG on the patient — or when compared with serial ECG changes over time</i><b>)</b>. </li><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>1:</u> Even with an ongoing, extensive acute MI — the initial <i>high-sensitivity</i> troponin may sometimes be normal.</li><li><br /></li><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>2:</u> It is important to note <u>and</u> correlate the presence and relative severity of symptoms with <u style="font-style: italic;">each</u> serial ECG that is done. This is because the course of an <b><i>acute</i></b> <b>OMI</b> <b>(</b> = <i>an acute <u>MI</u> that results from acute coronary <u>O</u>cclusion</i><b>)</b> — is not always predictable. Instead, <b>even <u style="font-style: italic;">before</u> treatment — there may be <i>spontaneous</i> reopening of the "culprit" vessel</b> — which often <u style="font-style: italic;">can</u> be recognized by <i>reduced</i> CP that occurs in association with <i>improved</i> ECG changes.</li><li>Spontaneous reopening of the "culprit" vessel may result in <b><i>"pseudo-normalization"</i></b> of ECG changes <b>(</b><i>IF the ECG is recorded "between" the stage of acute ST elevation — and the later stage of coronary reperfusion as ST elevation evolves into ST depression and T wave inversion</i><b>)</b>. </li><li><br /></li><li><b><u>KEY <i>Clinical</i> Point:</u></b> This <i>"pseudo-normalization"</i> stage still <i>mandates</i> prompt cath with PCI, because <i>what<b> spontaneously reopens — </b>may just as easily<b> reocclude</b></i> at <u style="font-style: italic;">any</u> point in time if not prevented by PCI.</li></ul><div><br /></div><div>========================</div><div><br /></div><div><b><u><span style="color: red;">C</span>HALLENGE:</u></b></div><div>With the above caveats in mind — <i>Take Another LOOK</i> at today's <b><i><u>initial</u></i></b> <b>ECG</b> in <u>Figure-1</u>:</div><div><ul><li><i>Which <b>single lead</b> in</i> <b><u>ECG #1</u> </b><i>tells the tale? </i></li></ul><div><i><br /></i></div></div><div><i><br /></i></div><div><i><br /></i></div><div><i><br /></i></div><div><b><u><span style="color: red;">A</span>NSWER</u> (<i>shown below</i>):</b></div><div>I highlight the answer to the above <i>"Challenge Question"</i> in <b><u>Figure-2</u>:</b></div><div><b><br /></b></div></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhZBDDjZA_47GQmoY1k0T0p4hBLzu7wGv_Vu61QLak3k4y5KR2FwJlsapO6SSJWLT4I_CEaBTZneClU7U3LLWNOuWrQReERMIBBi5kuBjiRo30NBnw4Jc4XPqgs8udIJIPCqXAniIJWT6juvBcDjZ4ywDEKvsjWMg2YV6XCQGfNva08g6MYcKQtfVKzcjk/s3784/Figure-2%20%20ECG-1%20(2-6.21-2024-labeled-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1742" data-original-width="3784" height="184" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhZBDDjZA_47GQmoY1k0T0p4hBLzu7wGv_Vu61QLak3k4y5KR2FwJlsapO6SSJWLT4I_CEaBTZneClU7U3LLWNOuWrQReERMIBBi5kuBjiRo30NBnw4Jc4XPqgs8udIJIPCqXAniIJWT6juvBcDjZ4ywDEKvsjWMg2YV6XCQGfNva08g6MYcKQtfVKzcjk/w400-h184/Figure-2%20%20ECG-1%20(2-6.21-2024-labeled-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: start;"><u>Figure-2:</u></b><span style="text-align: start;"> I highlight the <i>KEY</i> lead in today's initial ECG.<br /></span></span></td></tr></tbody></table><div style="text-align: justify;"><br /></div><div style="text-align: justify;"> </div><div style="text-align: justify;">========================</div><div style="text-align: justify;"><b><u><i>Regarding</i> ST-T Wave Changes in Figure-2:</u></b></div><div style="text-align: justify;">As per the title of today's ECG Blog — one <i>KEY</i> lead "tells the tale".</div><div style="text-align: justify;"><ul><li>ST-T wave changes in the <u style="font-style: italic;">limb</u> leads show <i>nonspecific</i> ST-T wave flattening — <i>but <u>nothing</u> that looks acute</i>.</li><li>I've highlighted within the <i>RED </i>rectangle in <u>Figure-2</u> the <i>single</i> lead <b>(</b><i> = </i><b><i>lead V3</i>)</b> that in a patient with <b>new <i>severe</i> CP</b> is clearly abnormal. While a slightly elevated, gently upsloping ST segment is common and normal in leads V2,V3 — there is definite <u style="font-style: italic;">straightening</u> of the ST segment in this lead on the <b><i><u>initial</u></i></b> <b>ECG</b> — and the <u style="font-style: italic;">amount</u> of ST elevation <b>(</b><i>seen with respect to the dotted RED line in this V3 lead</i><b>)</b> is excessive. This represents a <b><u style="font-style: italic;">hyperacute</u> ST-T wave</b> in lead V3 <u style="font-style: italic;">until</u> proven otherwise! </li></ul><div><br /></div><div><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>3:</u> To emphasize that <b>lead V3</b> is the <i>KEY</i> lead in today’s <span style="font-style: italic;">initial</span> ECG — without which I would not have diagnosed acute OMI. But since we <u style="font-style: italic;">know</u> (<i>for the reasons stated above</i>) that in a patient with new CP, that the ST-T wave in lead V3 is <u style="font-style: italic; font-weight: bold;">hyperacute</u> — I <i>also</i> interpreted the 2 <b><u style="font-style: italic;">neighboring</u> leads </b>in Figure-2<b> (</b><i> = </i><b style="font-style: italic;">leads V2</b><i> and </i><b><i>V4</i>)</b> as abnormal <u>and</u> consistent with <b><i>acute</i> LAD OMI</b> <u style="font-style: italic;">until</u> proven otherwise:</div><div><ul><li><u style="font-weight: bold;">Lead V2</u> — The <i>amount</i> of ST elevation in lead V2 is <u style="font-style: italic;">not</u> necessarily excessive, given how common slight ST elevation is normally seen in anterior leads V2,V3. But in the context of <b>lead V3</b> definitely showing a <i>hyperacute </i>ST-T wave — I thought there was a bit more “straightening” of the initial part of the ST segment in <b>lead V2</b> that I would normally expect (<i>at least in the 1st complex in this lead</i>).</li><li><u style="font-weight: bold;">Lead V4</u> — While <u style="font-style: italic;">not</u> necessarily abnormal if looked at as an isolated finding — I thought the amount of ST elevation in <i>neighboring</i> <b>lead V4</b> to be a bit more than is usually expected in this lead. And, at least for the middle complex in this lead — there seemed to be a bit <i>more-than-expected</i> ST segment straightening.</li><li><br /></li><li><u style="font-weight: bold;">To EMPHASIZE:</u> If not for lead V3 — I would <u style="font-style: italic;">not</u> have interpreted leads V2 and V4 as necessarily abnormal. This is especially true in view of: <b>i<span style="color: red;">)</span></b> The surprisingly good R wave progression that we see in <u>ECG #1</u> — with an R wave of already 7-8 mm by lead V2 <b>(</b><i>whereas there is commonly “loss of R wave” in anterior leads with acute LAD OMI</i><b>)</b>; <u>and</u>, <b>ii<span style="color: red;">)</span></b> The complete lack of abnormality in the remaining chest leads <b>(</b><i> = leads V1,V5,V6</i><b>)</b>. <b><i>It is lead V3 that "tells the tale"!</i></b></li></ul></div></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>4:</u> As stated earlier — an initial ECG will <u style="font-style: italic;">not</u> always be diagnostic. The <i>KEY</i> is to appreciate that in most patients — <b>the process of an acutely evolving coronary occlusion is <u style="font-style: italic;">dynamic</u> — sometimes showing dramatic changes in <i>as short</i> a period as between 5-10 minutes</b> <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2015/07/ecg-blog-115-early-repolarization.html" target="_blank">ECG Blog 115</a> </b><i>for a case in which such dramatic ST-T wave changes occurred in just 8 minutes!</i><b>)</b>.</div><div style="text-align: justify;"><ul><li>The <b><i>“<u>Take</u>-<u>Home</u>”</i></b> <b>Message</b> from <i>today's </i>case is clear — IF you are <i>at all uncertain</i> about whether your patient with CP is <u>or</u> is not acutely evolving an OMI — <b><i>Repeat the ECG <u>soon</u> and <u>often</u> — <u>until</u> you can confidently answer this question!</i></b></li></ul><div><br /></div><div><br /></div><div><b><u><i>Today's</i> <span style="color: red;">C</span>ASE <span style="color: red;">C</span>ontinues:</u></b> </div><div>Given any uncertainty you might have as to whether today's patient was evolving an acute OMI — the <u style="font-style: italic;">initial</u> ECG should have been repeated <i>within</i> 15-20 minutes.</div><div><ul><li>The ECG was only repeated 80 minutes later. To facilitate comparison in <u style="font-weight: bold;">Figure-3</u> — I have put these first 2 ECGs together. <b><i>What do YOU see?</i></b></li></ul></div></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi00V-wadABLafZ0xa3FvHcZ_QnrP7vy-PT8wa5t3MxHtXLW_ltT_b24INdYtWuwT4FydLCzmgqhoP3DvQEqZUyj2KjlvPa0dkFHsCcAvmGLv-RXQ7zSS5pJ4alG9lDET8nGIPdYoMNDjhWPdR46_ZpadLggrFy7pSEnaDDFSO9KjaRScqY5Ji3-SIb9vc/s2894/Figure-3%20%20ECGs-1,2%20(2-6.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2696" data-original-width="2894" height="373" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi00V-wadABLafZ0xa3FvHcZ_QnrP7vy-PT8wa5t3MxHtXLW_ltT_b24INdYtWuwT4FydLCzmgqhoP3DvQEqZUyj2KjlvPa0dkFHsCcAvmGLv-RXQ7zSS5pJ4alG9lDET8nGIPdYoMNDjhWPdR46_ZpadLggrFy7pSEnaDDFSO9KjaRScqY5Ji3-SIb9vc/w400-h373/Figure-3%20%20ECGs-1,2%20(2-6.21-2024)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span><b style="text-align: start;"><u>Figure-3:</u></b><span style="text-align: start;"> </span></span><span style="text-align: start;">To facilitate comparison — I've put the first 2 tracings in today's case together. <b><i>What has changed?</i></b></span><span><span style="text-align: start;"> </span></span><b>(</b><i>To improve visualization — I've digitized the original ECG using</i><span> </span><b><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span>.</span></span></td></tr></tbody></table><br /><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>Comparison <i>between</i> ECG #1 and ECG #2:</u></b></div><div style="text-align: justify;">The <i>BEST</i> way to compare serial ECGs — is to put them <i>side-by-side</i>, as I have done in <u>Figure-3</u>.</div><div style="text-align: justify;"><ul><li>Given our concern regarding <b>lead V3</b> in <u>ECG #1</u> — I began assessment of <u style="font-weight: bold;">ECG #2</u> by looking at this lead, and at its <i>neighboring</i> leads.</li><li>Compared to ECG #1 — there is now unmistakeable straightening of the ST segment takeoff in <b>lead V3</b> of ECG #2, with reduced T wave amplitude.</li><li><b>Lead V4</b> in ECG #2 — is now unmistakeably elevated (<i>with straightened ST segment takeoff</i>).</li><li>Each of the remaining chest leads <i>also</i> show differences. There is <i>subtle-but-real</i> ST elevation now in <b>leads V1</b>, <b>V2</b> and <b>V5</b> — and some ST depression in <b>lead V6</b> than was not previously present. </li><li><br /></li><li><u style="font-style: italic;">Limb</u> lead changes in ECG #2 are subtle — but in the context of the above noted chest lead changes, I believe the slightly increased inferior lead T wave amplitude and ST-T wave flattening in lead aVL is real.</li><li><br /></li><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>5:</u> <i>Did YOU Notice</i> the <b><i><u>loss</u></i></b> <b>of R wave amplitude</b> in ECG #2? There is now a QS pattern in lead V2, with noticeably reduced R wave amplitude in leads V2-thru-V5 compared to ECG #1. </li></ul><u style="font-weight: bold;"><div style="text-align: justify;"><u style="font-weight: bold;"><br /></u></div>BOTTOM Line:</u> If there was doubt about the diagnosis from ECG #1 — the repeat ECG in <u>Figure-3</u> is now clearly diagnostic of <b><i>acute</i> LAD OMI</b> because: <b>i</b><span style="color: red;">)</span> <i>Dynamic</i> ST-T wave changes are seen in virtually <u style="font-style: italic;">all</u> leads compared to the initial tracing — including <b><i>progressive</i></b> <b>ST elevation</b> in leads V2-thru-V5; <u>and</u>, <b>ii<span style="color: red;">)</span></b> <b>Loss of R wave amplitude</b> in these chest leads.<br /><ul><li><b><u>The <i>Important</i> LESSON:</u></b> Given the history of new-onset severe CP — acute LAD OMI can be diagnosed (<i>or at least strongly suspected</i>) from the initial ECG in today's case. But even if there was uncertainty about <u>ECG #1</u> — definitive diagnosis could have been made much sooner by repeating this initial tracing within 10-15 minutes (<i>instead of waiting 80 minutes</i>).</li></ul><div><br /></div><div><br /></div><div><div><b><u><span style="color: red;">C</span>ASE <span style="color: red;">C</span>onclusion:</u></b> </div><div>The diagnosis of acute LAD OMI was made once the repeat ECG in Figure-3 was obtained. Given unavailability of cardiac catheterization — <b>Streptokinase</b> was administered.</div><div><ul><li><u style="font-weight: bold;">ECG #3</u> was recorded after completion of Streptokinase infusion — in association with clinical improvement. <b><i>What do YOU see?</i></b></li></ul></div></div></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhr32EW74rIHasO2RyUAhYA1Hb4AqCINF0m7bNuzBPrtQYqWMtdVtHBJnFSm_ijxWYZIPN8kBELkPQ2eZYZ0cP1pGaU7Azkh9bV-qnknJh4bNrNFmS0B0SRW6B7b3uE7ukzgsMffbxUoK8VREV6Y3RnOosqnJ64pGJEglsoBvWC1WCCrtMNy_fvfgsw0Go/s3096/Figure-4%20%20ECGs-2,3%20(2-6.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2768" data-original-width="3096" height="358" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhr32EW74rIHasO2RyUAhYA1Hb4AqCINF0m7bNuzBPrtQYqWMtdVtHBJnFSm_ijxWYZIPN8kBELkPQ2eZYZ0cP1pGaU7Azkh9bV-qnknJh4bNrNFmS0B0SRW6B7b3uE7ukzgsMffbxUoK8VREV6Y3RnOosqnJ64pGJEglsoBvWC1WCCrtMNy_fvfgsw0Go/w400-h358/Figure-4%20%20ECGs-2,3%20(2-6.21-2024)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span><b style="text-align: start;"><u>Figure-4:</u></b><span style="text-align: start;"> Comparison of <b><u>ECG #2</u></b> — with <b><u>ECG #3</u></b>, recorded <b><i><u>after</u></i></b> completion of <b>Streptokinase</b>.</span></span><span><span style="text-align: start;"> </span></span><b>(</b><i>To improve visualization — I've digitized the original ECG using</i><span> </span><b><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span>.</span></span></td></tr></tbody></table><br /><div style="text-align: justify;"> </div><div style="text-align: justify;"><div><b><u><i>Regarding</i> the <i>Post-Streptokinase </i>ECG in Figure-3:</u></b></div><div>Streptokinase infusion was effective!</div><div><ul><li>Other than slight residual ST elevation in leads V1,V2 — ST elevation in other chest leads has essentially resolved!</li><li>Although there has been loss of R wave amplitude compared to the <i>initial</i> ECG — there has been <u style="font-style: italic;">no</u> further loss of R wave amplitude since ECG #2.</li><li>There is now terminal T wave inversion — that begins in lead V2, and extends through to lead V6. In association with clinical improvement of this patient — <u>ECG #3</u> now shows <b><u style="font-style: italic;">reperfusion</u> T waves</b> consistent with effective thrombolytic infusion.</li></ul></div></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><div><span style="font-family: arial; font-size: medium;"><div><span style="color: #333333;"><span style="font-family: arial;">==================================</span></span></div><div><span style="font-family: arial;"><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Kianseng Ng (<i>from Malaysia</i>) for the case and this tracing.</span></div><div><span style="color: #333333;">==================================</span></div></span></div><p class="MsoNormal" style="margin: 0in;"><span face="Arial, sans-serif"></span></p><div><span style="font-family: arial; font-size: medium; text-align: left;"><div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span style="font-family: arial;"><br /></span></span></p><div style="text-align: justify;"><div><span style="font-family: arial;"><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></div><div><p class="MsoNormal" style="margin: 0in;"></p><ul><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span>S</span>ystematic</i></b> <b><span>A</span>pproach</b> to 12-lead ECG Interpretation.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-193-ecg-mp-10-acute-omi.html" target="_blank">ECG Blog #193</a></b> — Reviews the basics for <i>predicting</i> the <b><i>"<u>culprit</u>"</i></b> <b>artery</b> </span><b>(</b><i>as well as reviewing why the term <b>"STEMI"</b> — should be replaced by <b>"OMI"</b> = <u>O</u>cclusion-based MI</i><b>)</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial;">Recognizing <b><i><u>hyperacute</u></i></b> <b>T waves</b> — patterns of leads — an <b>OMI (</b><i>though <u>not</u> a STEMI</i><b>)</b> — See <i>My Comment</i> at the bottom of the page in the <b><a href="http://hqmeded-ecg.blogspot.com/2020/11/this-skill-can-be-taught-and-learned.html" target="_blank">November 8, 2020</a> post</b> on Dr. Smith's ECG Blog.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2022/03/ecg-blog-294-one-hour-later.html" target="_blank">ECG Blog #294</a></b> — Reviews how to tell <b><i>IF the "<u>culprit</u>" artery has reperfused</i></b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/06/ecg-blog-230-46-are-there-serial-ecg.html" target="_blank">ECG Blog #230</a></b> — Reviews how to <b><i>compare</i></b> <b><i><u>serial</u></i></b> <b>ECGs</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2015/07/ecg-blog-115-early-repolarization.html" target="_blank">ECG Blog #115</a></b> — Shows how dramatic ST-T changes can occur in as short as an 8-minute period.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-268-76-mobitz-i-vs-complete-av.html" target="_blank">ECG Blog #268</a></b> — Shows an example of <b><i><u>reperfusion</u></i></b> <b>T waves</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2023/10/ecg-blog-400-is-this-nstemi.html" target="_blank">ECG Blog #400</a></b> — Reviews the concept of <b><i>"<u>dynamic</u>"</i> ST-T wave changes</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2022/10/ecg-blog-337-nstemi-or-omi.html" target="_blank">ECG Blog #337</a></b> — A <i>"NSTEMI"</i> that was really an <b><i>ongoing</i></b> <b>OMI</b> of <i>uncertain</i> duration <b>(</b><i>presenting with inferior lead <u>reperfusion</u> T waves</i><b>)</b>.</li></ul><div><br /></div></div></div></div><p class="MsoNormal"><span style="font-family: arial;"></span></p><div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhcUanPtyekRxG_NN3M6G7ixBWDiaFwP9HSTmmxsiAGLgKFyGGIePOLicsrDGS_HrTpJuFvbsUgWw_X6ZXKehXoAeVAyPHHXStk2lmG9uzuY33nE1KZQCLDvOH1VKIkbTzKmck2XR3I6_wmONnxXQmAen5uT-Ez0rJCH23wswN1g0uETqzQQugv30VE=s613" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/a/AVvXsEhcUanPtyekRxG_NN3M6G7ixBWDiaFwP9HSTmmxsiAGLgKFyGGIePOLicsrDGS_HrTpJuFvbsUgWw_X6ZXKehXoAeVAyPHHXStk2lmG9uzuY33nE1KZQCLDvOH1VKIkbTzKmck2XR3I6_wmONnxXQmAen5uT-Ez0rJCH23wswN1g0uETqzQQugv30VE=w400-h16" width="400" /></a></span></div></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div><br /></div></span></div></div></span>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com2tag:blogger.com,1999:blog-3364570834099131201.post-33015626213828228142024-02-17T08:43:00.001-05:002024-02-23T20:37:41.511-05:00ECG Blog #417 — AFib with Aberrancy? <span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;">The ECG in <b style="text-decoration: underline;">Figure-1</b> was obtained from a previously healthy middle-aged man — who presented to the ED (<i><u>E</u>mergency <u>D</u>epartment</i>) for shortness of breath. </div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>QUESTIONS:</u></b></div><div style="text-align: justify;"><ul><li><i>How would YOU interpret</i> the ECG shown in <u>Figure-1</u>?</li><li>Given the <i>irregular irregularity </i>of beats #4-through 17 — Is this a run of <b>AFib (</b><i><u>A</u>trial <u>Fib</u>rillation</i><b>)</b> with <b><i>aberrant</i></b> <b>conduction?</b></li></ul></div></span><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhS_1vYTyVVTLSSulzGkxQkQwkge3FrFnTfrlvjWcc1GrFQmm0bmX_Uz7nXCBpUviPYRGvD5h4VgwRz9OZMQE5f9osHjjsIndQP6Lq4JRS_AgoOUszanekHcYwZid_2A8LKjsJEyxR-Od9sXpeGDgaRX9dpIJXF0-VN-C2cvDnUYWXbeCNUg5iptlDgvVs/s3784/Figure-1%20%20ECG-1%20Revised%20(1-6.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2294" data-original-width="3784" height="242" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhS_1vYTyVVTLSSulzGkxQkQwkge3FrFnTfrlvjWcc1GrFQmm0bmX_Uz7nXCBpUviPYRGvD5h4VgwRz9OZMQE5f9osHjjsIndQP6Lq4JRS_AgoOUszanekHcYwZid_2A8LKjsJEyxR-Od9sXpeGDgaRX9dpIJXF0-VN-C2cvDnUYWXbeCNUg5iptlDgvVs/w400-h242/Figure-1%20%20ECG-1%20Revised%20(1-6.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-1:</u></b><span style="text-align: start;"> The <b><i><u>initial</u></i></b> <b>ECG</b> in today's case.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>Initial Thoughts</i> on the ECG in Figure-1:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Today's ECG is challenging because <i><u>despite</u></i> the marked change in QRS morphology beginning with beat #4 — <b><i>monomorphic</i></b> <b>VT (</b><i><u>V</u>entricular <u>T</u>achycardia</i><b>)</b> is usually a regular (<i>if not, at least fairly regular</i>) rhythm. This raises the question if beats #4-thru-17 might represent a run of AFib with <i>aberrant</i> conduction?</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">HINT:</u> The <i>KEY</i> to interpreting today's rhythm lies with assessment of atrial activity. <i>What do YOU see?</i></span></li></ul></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">=====================================</span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><i><u>Does this Earlier Tracing Help?</u></i></b></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">Another ECG had been recorded on today's patient shortly <i>before</i> the ECG shown in </span><u style="font-family: arial; text-align: left;">Figure-1</u><span style="font-family: arial; text-align: left;">. </span></span></div><div style="text-align: justify;"><ul><li style="text-align: left;"><span style="font-family: arial; font-size: medium;">Does this <b><i>earlier</i></b> <b>tracing</b> <b>(</b><i>shown in</i> <b><u>Figure-2</u>)</b> help to determine the etiology of the run of irregular wide beats in <u>Figure-1</u>?</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjd3z5pAb6DEh5I-gbmKaq9d-uzZEIuf-eybabbE9m7ibmBTWnbRljtTEMyE-UMpx4W__PLFSVQ0T1zjmpRYIrgGVAWTDjT5zggZHcusyuqA-rrW2zZqJA0w0wrJQZAmjquXy5oNdUdzkBrbLB_C78ZeadWubYApluPsMnd5mViW6Hw01amBVIiZz1Sibo/s3786/Figure-2%20%20ECG-2%20Revised%20(1-6.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2276" data-original-width="3786" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjd3z5pAb6DEh5I-gbmKaq9d-uzZEIuf-eybabbE9m7ibmBTWnbRljtTEMyE-UMpx4W__PLFSVQ0T1zjmpRYIrgGVAWTDjT5zggZHcusyuqA-rrW2zZqJA0w0wrJQZAmjquXy5oNdUdzkBrbLB_C78ZeadWubYApluPsMnd5mViW6Hw01amBVIiZz1Sibo/w400-h240/Figure-2%20%20ECG-2%20Revised%20(1-6.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-2:</u></b><span style="text-align: start;"> A 2nd ECG in today's case. This tracing was recorded shortly <i>before</i> <u>ECG #1</u>. <i>Does this earlier tracing </i></span></span><span style="font-family: arial; font-size: medium;"><i>help to determine the etiology of the wide beats?</i></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br />=====================================<br /><span><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>My Approach</i> to <i>Today's</i> Rhythm:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Atrial activity <u><i>is</i></u> present in association with <i><u>each</u></i> of the beats in <i><u>both</u></i> of today’s tracings. This atrial activity provides the <i>KEY</i> clue for determining the etiology of the wide beats. </span></div><div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Using <u style="font-style: italic; font-weight: bold;">calipers</u> facilitates the process.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">HINT:</u> We need to look for P waves <i><u>not</u> <u>only</u> in front </i>of the wide beats — but also <i>during</i> <u>and</u> <i>just after</i> the wide QRS complexes in order to complete our search for atrial activity.</span><span style="font-family: arial; font-size: large;"> </span></li></ul></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>QUESTION:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">I’ve put both tracings together in <u style="font-weight: bold;">Figure-3</u>.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><i>How do the colored arrows provide the answer?</i></span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNe43guMEFK83YTu91Fs6BAx47zOa9wgTsIoI1dyqTnYD7Lq_gWEIAnoS81dKMPjC9J0JL1K4ulrFOqIFbTsQ7VWhWMO1nm9ZUhJ7LDQcNPx693Srah_pX5HEP2C3jngn-MGcmJ3MXtsO73iQjFADxcDmR-fisoiKy99KSHMtrcPRpRQ00NlVnUnQB7LM/s2870/Figure-3%20%20ECGs-1,2%20labeled%20(1-6.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2870" data-original-width="2356" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgNe43guMEFK83YTu91Fs6BAx47zOa9wgTsIoI1dyqTnYD7Lq_gWEIAnoS81dKMPjC9J0JL1K4ulrFOqIFbTsQ7VWhWMO1nm9ZUhJ7LDQcNPx693Srah_pX5HEP2C3jngn-MGcmJ3MXtsO73iQjFADxcDmR-fisoiKy99KSHMtrcPRpRQ00NlVnUnQB7LM/w328-h400/Figure-3%20%20ECGs-1,2%20labeled%20(1-6.21-2024)-USE.png" width="328" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-3:</u></b><span style="text-align: start;"> I’ve put both tracings in today’s case together — and have labeled atrial activity with colored arrows.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>The ANSWER to <i>Today’s</i> Rhythm:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">The first 3 beats in <u style="font-weight: bold;">ECG #1</u> are <b><i>sinus</i></b> <b>conducted</b> — with <i>RED arrows</i> highlighting <i>on-time</i> sinus P waves.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Note that a 4th <i>on-time</i> sinus P wave occurs <i>just before</i> the 1st wide beat in the long lead II rhythm strip seen in <u>Figure-3</u> <b>(</b> = <i>the 4th RED arrow in ECG #1 that appears just before </i><b><i>beat #4</i>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;">Note also that a subtle <i>negative</i> deflection occurs at the very end of the 2nd wide QRS complex <b>(</b> = <i>the 1st YELLOW arrow in the long lead II rhythm strip of ECG #1</i><b>)</b>. This <i>YELLOW arrow</i> represents a <b><i><u>retrograde</u></i></b> <b>P wave</b>.</span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;"><i>KEY </i>Point:</u> The above events <u style="font-style: italic;">prove</u> that <b>beat #4 </b>and <b>beat #5</b> are <b>PVCs (</b><i><u>P</u>remature <u>V</u>entricular <u>C</u>ontractions</i><b>)</b>.</span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">Several points should be emphasized regarding <b><u>ECG #1:</u></b></span></div><div><ul><li><span style="font-family: arial; font-size: medium;">The reason we <u style="font-style: italic;">know</u> that the subtle negative deflection ( = <i>that 1st YELLOW arrow in </i><u>ECG #1</u>) that appears at the end of beat #5 <u>is</u> definitely a <i>retrograde</i> P wave — is that we see <u style="font-style: italic;">no</u> such negative deflection at the end of beat #4. This is as expected — because an <i>on-time</i> sinus P wave appears just <i>before</i> beat #4, and this renders the atria refractory to retrograde conduction.</span></li><li><span style="font-family: arial; font-size: medium;">Of interest — <b><i>retrograde</i> P waves (</b><i>highlighted by YELLOW arrows</i><b>)</b> are seen at the very same point <b>(</b>ie, <i>just after the QRS complex</i><b>)</b> of beats #6-thru-17.</span></li><li><span style="font-family: arial; font-size: medium;">Further support that the subtle negative deflections at the end of the wide beats are indeed <i>retrograde</i> P waves — is forthcoming from our ability to see these retrograde P waves in <i>other</i> leads in the 12-lead tracing <b>(</b><i>= YELLOW arrows in multiple other leads in ECG #1</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;">Returning to the long lead II rhythm strip in <u>ECG #1</u> —<b> Beat #17</b> is followed by a brief pause, after which the 5th <i>RED arrow</i> in this tracing highlights resumption of <b><i>sinus</i></b> <b>rhythm</b> with <b>beat #18</b>.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>1:</u> The polarity of a P wave that appears shortly after a QRS complex helps to distinguish between sinus P waves, PACs (<i><u>P</u>remature <u>A</u>trial <u>C</u>ontractions</i>) and <u style="font-style: italic;">retrograde</u> P waves. <b>Sinus P waves should be <i>positive</i> in lead II</b>. They are often (<i>albeit not always</i>) negative in lead V1. PACs may <i>either</i> be positive or negative. But <b><u style="font-style: italic;">retrograde</u> P waves</b> should be <u style="font-style: italic;"><b>negative</b></u> in <b><i>inferior</i></b> <b>leads (</b><i>II,III,aVF</i><b>) </b>— and <u style="font-style: italic;">positive</u> in leads aVR and V1 <b>(</b><i>as seen by the YELLOW arrows in </i><u>ECG #1</u><b>)</b>.</span></li><li><br /></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL </u><span style="color: red; font-weight: bold; text-decoration: underline;">#</span><span style="font-weight: bold; text-decoration: underline;">2:</span><span> The fact the 4th sinus P wave in ECG #1, as shown in <u>Figure-3</u> <b>(</b><i> = the 4th RED arrow in the long lead rhythm strip</i><b>)</b> is completely <i>on-time,</i> and is followed by a wide beat that is preceded by a PR interval <i>too short</i> to conduct — proves that <b>beat #4</b> is a <b>PVC</b>.<b> (</b><i>Since the PR interval before beat #4 is too short to conduct normally — this means that beat #4 must be coming at least in part, from <u>below</u> the AV Node</i><b>)</b>.</span></span></li><li><span style="font-family: arial; font-size: medium;"><span><u style="font-weight: bold;"><br /></u></span></span></li><li><span style="font-family: arial; font-size: medium;"><span><u style="font-weight: bold;">PEARL </u><span style="color: red; font-weight: bold; text-decoration: underline;">#</span><span style="font-weight: bold; text-decoration: underline;">3:</span> QRS morphology of wide beats #5-thru-17 is very similar to QRS morphology of beat #4. This strongly suggests that <u style="font-style: italic;">despite</u> the irregularity of beats #4-thru-17 — this represents a run of <b><i>irregular</i> VT</b>.</span></span></li><li><span style="font-family: arial; font-size: medium;"><span><u style="font-weight: bold;"><br /></u></span></span></li><li><span style="font-family: arial; font-size: medium;"><span><u style="font-weight: bold;">PEARL </u><span style="color: red; font-weight: bold; text-decoration: underline;">#</span><span style="font-weight: bold; text-decoration: underline;">4:</span> Beat #4 is a <b><u style="font-style: italic;">fusion</u> beat</b>. As noted in PEARL #3 — QRS morphology of <b>beat #4</b> looks very similar <b>(</b><i>but is <u>not</u> identical</i><b>)</b> to QRS morphology of beats #5-17 <b>(</b>ie, <i>The R wave of beat #4 is slightly shorter than the R wave of <u>each</u> of the 13 wide beats that follow it</i><b>)</b>. To prove “fusion” — there should be a logical reason for a beat to manifest an intermediate morphology between sinus-conducted beats and pure ventricular beats — and this logical reason <u><i>is</i></u> present in <u>ECG #1</u> — because the <i>on-time</i> 4th <i>RED arrow</i> sinus P wave (<i>that is seen just before beat #4</i>) has no more than a very brief moment of time to conduct to the ventricles before ventricular beat #4 arises. <b>(</b><i>For more on <u>fusion</u> beats — See </i><b><a href="https://ecg-interpretation.blogspot.com/2016/06/ecg-blog-128-vt-fusion-wct-sinus.html" target="_blank">ECG Blog #128</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2016/07/ecg-blog-129-pvc-late-cycle-end.html" target="_blank">Blog #129</a>)</b>. </span></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">KEY <i>Clinical</i> Point:</u> The finding of a <b><u style="font-style: italic;">fusion</u> beat</b> — provides further support that <i>not only</i> is beat #4 in <u>ECG #1</u> at least in part of ventricular etiology — but <i>also, </i>that <u style="font-style: italic;">each</u> of the wide beats that look like beat #4 <b>(</b> = <i>beats #5-17</i><b>)</b> are also of ventricular etiology, such that we have proven that beats #4-thru-17 represent a run of <b><i>irregular </i>VT! (</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2016/12/ecg-blog-133-aberrant-conduction-vt.html" target="_blank">ECG Blog #133</a>)</b>.</span></li></ul><div><span style="font-family: arial; font-size: medium;"><b><br /></b></span></div></div><div><div style="text-align: left;"><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>PEARL <span style="color: red;">#</span>5:</u></b><span> One of the main reasons I chose today’s case is to emphasize that although <b><i>monomorphic</i></b> <b>VT</b> is <i><u>usually</u></i> a regular rhythm — it is</span><b> <i><u>not</u></i> always a regular rhythm (</b><i>See the</i><span> </span><b>ECG Media Pearl </b><i>in today’s ADDENDUM below</i><b>)</b><span>. </span></span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><span style="font-family: arial;">Most of the time when <i>monomorphic</i> VT is not regular — the amount of “irregularity” is minimal. That said — Today’s case represents an example in which we <i>know</i> the rhythm is VT <u style="font-style: italic;">despite</u> the <i>marked</i> irregularity that we see in <u>ECG #1</u>.</span></span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-size: medium;"><span style="font-family: arial;">The reason most monomorphic VT manifests a regular (<i>or at least almost regular</i>) R-R interval — is that this rhythm is most often the result of a <b>stable <i>reentrant</i> circuit</b>. </span><span style="font-family: arial;">There may be a brief <b><i>"warm-up"</i></b> <u>or</u> <b><i>"cool-down" </i><u>period</u></b> until a regular R-R interval is established <b>(</b><i>in which case there is gradual acceleration <u>or</u> deceleration of the rate — either at the beginning or the end of an otherwise regular run of VT</i><b>)</b>.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;">The above said — On occasion, there may be <b>focal <i><u>triggered</u></i> activity</b> that results in the marked irregularity of the <i>monomorphic</i> VT seen in <u>ECG #1</u> <b>(</b></span><span style="font-family: arial; text-align: left;"><i>Zhang et al </i>— </span><b style="font-family: arial; text-align: left;"><a href="https://www.ahajournals.org/doi/epub/10.1161/CIRCULATIONAHA.118.039018" target="_blank">Circulation 139:1750-1752, 2019</a>)</b><span style="font-family: arial; text-align: left;">.</span><b style="font-family: arial; text-align: left;"> </b></span></li><li><u style="font-family: arial; font-weight: bold; text-align: left;"><span style="font-size: medium;"><br /></span></u></li><li><span style="font-size: medium;"><u style="font-family: arial; font-weight: bold; text-align: left;">P.S.:</u><span style="font-family: arial; text-align: left;"> The reason for specifying the </span><b style="font-family: arial; text-align: left;"><i>“<u>monomorphic</u>”</i></b><span style="font-family: arial; text-align: left;"> form of VT as the VT rhythm that is usually regular — is that by definition, </span><b style="font-family: arial; text-align: left;">PMVT (</b><i style="font-family: arial; text-align: left;"><u>P</u>oly<u>M</u>orphic <u>V</u>entricular <u>T</u>achycardia</i><b style="font-family: arial; text-align: left;">)</b><span style="font-family: arial; text-align: left;"> is a very <i>irregular</i> VT rhythm that quickly leads to hemodynamic instability </span><b style="font-family: arial; text-align: left;">(</b><i style="font-family: arial; text-align: left;">See </i><b style="font-family: arial; text-align: left;"><a href="https://ecg-interpretation.blogspot.com/2021/06/ecg-blog-231-what-is-this-bizarre.html" target="_blank">ECG Blog #231</a>)</b><span style="font-family: arial; text-align: left;">.</span></span></li></ul></div></div></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i><br /></i></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i>=================================</i></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i><br /></i></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i>Regarding</i> <u style="font-weight: bold;">ECG #2</u> in <u>Figure-3:</u></span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><span style="font-family: arial;">As noted earlier — the bottom tracing in </span><u style="font-family: arial;">Figure-3</u><span style="font-family: arial;"> was recorded shortly before </span><u style="font-family: arial;">ECG #1</u><span style="font-family: arial;">. </span><span style="font-family: arial;"><i><b>What additional information is provided </b>by </i><u style="font-weight: bold;">ECG #2</u><b> — </b></span><span style="font-family: arial;">that was</span><b style="font-family: arial;"> <u style="font-style: italic;">not</u> evident </b><span style="font-family: arial;">in</span><b style="font-family: arial;"> <u>ECG #1</u>?</b></span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>ANSWER:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">In addition to further confirmation that the wide beats in today’s 2 tracings are ventricular in etiology — <u>ECG #2</u> provides insight to the <b><i>potential</i></b> <b><u>cause</u></b> of the today’s VT rhythm.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">In <u>Figure-3</u> — <b>Beats #1</b>,<b>2</b>; <b>8</b>,<b> 10 </b>and<b> 15 </b>in <u>ECG #2</u> are <b>PVCs</b>, with beats #1 and 2 forming a <b><i>ventricular</i> couplet (</b><i> = 2 PVCs in a row</i><b>)</b>. We <u style="font-style: italic;">know</u> these 5 wide beats are all of ventricular etiology — <b>because the underlying atrial rhythm continues throughout this tracing <u><i>despite</i></u> these wide beats</b> <b>(</b>ie, <i>the 2 PINK arrow P waves slightly deform the initial upslope of the R wave of beats #8 and 10 — therefore with a PR interval too short to conduct. The 3 WHITE arrow P waves are contained within the QRS of wide beats #1,2,15 — </i><i>thereby making it impossible for these P waves to conduct</i><b>)</b>.</span></li></ul><span style="font-family: arial; font-size: medium;"><b><u><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><br /></u></b></span></div>PEARL <span style="color: red;">#</span>6:</u></b><span> <i>12 leads are <u>better</u> than one! </i></span></span><span style="font-size: medium;"><br /></span><ul><li><span style="font-size: medium;"><span style="font-family: arial;"><span>Although we see <u style="font-style: italic;">no</u> evidence that <i>WHITE arrow</i> P waves are hidden <i>within</i> the wide QRS beats #1,2 and 15 in the long lead rhythm strip of <u>ECG #2</u> — We <i><u>do</u></i> see a precisely <i>on-time</i> positive notch in <b>lead V6 </b></span></span><b style="font-family: arial;">(</b><i style="font-family: arial;">2nd RED arrow in this lead</i><b style="font-family: arial;">)</b><span style="font-family: arial;">. This</span><span style="font-family: arial;"> </span><u style="font-family: arial; font-style: italic;">confirms</u><span style="font-family: arial;"> that regular P waves </span><u style="font-family: arial; font-style: italic;">do</u><span style="font-family: arial;"> continue throughout today's rhythm. </span></span></li><li><span style="font-family: arial; font-size: medium;"><span>The above observation illustrates the concept of how use of <b><i>simultaneous </i>leads </b>can provide insight not forthcoming from a single lead<b> (</b><i>in this case — looking for evidence of atrial activity not only in the long lead rhythm strip — but also in simultaneously-recorded leads V4,V5,V6</i><b>)</b>.</span></span></li></ul><span style="font-family: arial; font-size: medium;"><b><u><div style="text-align: justify;"><br /></div>PEARL <span style="color: red;">#</span>7:</u></b><span> Most of the time, assessment of ST-T wave morphology of ventricular beats will <i><u>not</u></i> be a reliable indicator of a recent or acute event. As a result — We are only able to reliably assess ST-T wave morphology for acute changes in leads I,II,III of <u><b>ECG #1</b></u>, because these are the only 3 leads in which we see ST-T waves for sinus-conducted beats. These 3 leads suggest left axis deviation consistent with <b>LAHB (</b><i><u>L</u>eft <u>A</u>nterior <u>H</u>emi<u>B</u>lock</i><b>)</b> for sinus-conducted beats #1,2,3 — with <i>nonspecific</i> ST-T wave flattening, but <i><u>no</u> acute changes.</i></span></span><br /><ul><li><span style="font-family: arial; font-size: medium;"><span>In contrast to our inability to optimally assess <u>ECG #1</u> for ischemic changes — the <b><i>chest</i></b> <b>leads</b> in <u style="font-weight: bold;">ECG #2</u> clearly show suspicious changes for a recent acute event in <b><i>sinus-conducted</i></b> <b>beats #11</b>,<b>12</b>,<b>13</b> <b>(</b><i>that manifest abnormal straightening of the ST segment takeoff in anterior leads V2,V3</i><b>)</b> — <u>and</u> — in <b><i>sinus-conducted</i></b> <b>beats #14 </b>and <b>16 (</b><i>that show ST segment coving with symmetric T wave inversion in leads V4,V5,V6 — as well as a small amount of residual ST elevation in lead V4</i><b>)</b>.</span></span></li><li><span style="font-family: arial; font-size: medium;"><span><br /></span></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;"><i><span style="color: red;">C</span>linical</i> <span style="color: red;">I</span>MPRESSION:</u> Given the minimal amount of ST elevation in the chest leads of <u>ECG #2</u> — in association with symmetric T wave inversion in leads V4,V5,V6 — I suspect <b><i>reperfusion</i></b> <b>T waves</b> following recent <b>LAD (</b><i><u>L</u>eft <u>A</u>nterior <u>D</u>escending</i><b>) coronary artery occlusion </b>as the <b><i><u>cause</u></i></b> of the <b><i>irregular</i></b> <b>VT</b> and <b>PVCs</b> that we see in today’s 2 ECGs.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i>=================================</i></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i><br /></i></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">L</span>ADDERGRAM <span style="color: red;">I</span>llustration:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">To facilitate appreciation of the mechanism of today’s arrhythmia — I’ve added <i style="font-weight: bold;">laddergrams</i> for ECG #1 <u>and</u> ECG #2 in <b><u>Figure-4</u>.</b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Following 3 sinus-conducted beats — <b>beat #4</b> in <b><u>ECG #1</u> (</b><i>TOP laddergram</i><b>)</b> is a <b><u style="font-style: italic;">fusion</u> beat (</b><i>"F"</i><b>)</b>, after which a run of <b><i>irregular</i> VT </b>is seen <b>(</b><i> = beats #5-thru-17</i><b>)</b>. After a brief (<i>post-ectopic</i>) pause — sinus rhythm resumes with beat #18.</span></li><li><span style="font-family: arial; font-size: medium;"><i>YELLOW arrows </i>in <u>ECG #1</u> represent <b><i>retrograde</i> P waves</b> that are conducted back to the atria.</span></li><li><span style="font-family: arial; font-size: medium;">Note that I show the point of fusion for beat #4 at a relatively high point in the ventricles. Because QRS morphology of beat #4 closely resembles QRS morphology during the run of VT (<i>with the main difference in morphology being slightly less R wave amplitude for the fusion beat</i>) — the ventricular impulse contributing to beat #4 passes through <i>most</i> of the ventricles before encountering the sinus-conducted contribution to beat #4.</span></li><li><br /></li><li><span style="font-family: arial; font-size: medium;">In <u style="font-weight: bold;">ECG #2</u> <b>(</b><i>BOTTOM laddergram</i><b>) </b>— <b>beats #1</b>,<b>2</b>; <b>8</b>, <b>10 </b>and <b>15 </b>represent <b>PVCs</b>. These 5 ventricular impulses conduct only a short distance backward <b>(</b>ie, <i>into the AV Nodal Tier</i><b>)</b> before encountering the downward directed sinus-conducted impulses that prevent retrograde conduction of these PVCs from reaching the atria.</span></li></ul></div><div style="text-align: justify;"> </div></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKJjKtRTSh7ZJIdpb4PgcKEy3RM80tzXdwZCEo3mxHV4bx4zp3WTrB6k5lRCsYwWwxSNmk-1_pB7LlU2fRSUa2oh7dkisTXl1o7zHiAWqWoCjeEZi0okkiTh2yXLWmPVAPVgUu529hN5dzNNH6r9lHMrs5m91ZQKcjc8urRbaAlwJg4SpPRSWBAX5c3_Q/s3028/Figure-4%20-%20Ladder-ECGs-1,2%20(2-12.21-2024).png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2790" data-original-width="3028" height="369" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKJjKtRTSh7ZJIdpb4PgcKEy3RM80tzXdwZCEo3mxHV4bx4zp3WTrB6k5lRCsYwWwxSNmk-1_pB7LlU2fRSUa2oh7dkisTXl1o7zHiAWqWoCjeEZi0okkiTh2yXLWmPVAPVgUu529hN5dzNNH6r9lHMrs5m91ZQKcjc8urRbaAlwJg4SpPRSWBAX5c3_Q/w400-h369/Figure-4%20-%20Ladder-ECGs-1,2%20(2-12.21-2024).png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: start;"><u>Figure-4:</u></b><span style="font-family: arial; text-align: start;"> Laddergram illustration for the 2 ECGs in today’s case.</span></span></td></tr></tbody></table><br /><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: large; text-align: justify;">==========================================</span></div><div><span style="font-family: arial; font-size: medium;"><div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span><span><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Seung-Lyul Shin </span></span><span style="caret-color: rgb(5, 5, 5); color: #050505;">(</span><i style="caret-color: rgb(5, 5, 5); color: #050505;">from Incheon, South Korea</i><span style="caret-color: rgb(5, 5, 5); color: #050505;">) for the case and this tracing.</span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span>==========================================</span></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span><br /></span></p><div class="separator" style="clear: both; text-align: justify;"><span><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"></a></span></div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></span><span><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span> </span></p></div></span></div><div><span style="font-family: arial; font-size: medium;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span>==============================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><ul><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a> </b>— Reviews my System for <b><i>Rhythm</i></b> <b>Interpretation</b></span></span><span>, </span><span>using th</span><span>e </span><b><span style="color: red;">P</span>s, <span style="color: red;">Q</span>s & 3<span style="color: red;">R</span> Approach</b><span>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/02/blog-198-ecg-mp-15-can-vt-be-irregular.html" target="_blank">ECG Blog #198</a></b> — <b><i>Can VT be Irregular?</i></b></span></span></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2023/11/ecg-video-blog-403-220-psqs3rs-approach.html" target="_blank">ECG Blog #403</a> (</b><i>ECG Video</i><b>)</b> — Case of a <b><i><u>regular</u></i></b> <b>WCT</b> rhythm.</span></span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2016/06/ecg-blog-128-vt-fusion-wct-sinus.html" target="_blank">ECG Blog #128</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2016/07/ecg-blog-129-pvc-late-cycle-end.html" target="_blank">ECG Blog #129</a></b> — Reviews the concept of <b><i><u>Fusion</u></i></b> <b>beats</b>.</span></span></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2023/09/ecg-blog-393-why-so-many-shapes.html" target="_blank">ECG Blog #393</a></b> — Case of <b>multiple</b> <b><i><u>Fusion</u></i></b> <b>beats</b>.</span></span></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2016/12/ecg-blog-133-aberrant-conduction-vt.html" target="_blank">ECG Blog #133</a></b> — <b>AV Dissociation</b>, <b>Fusion</b> <i><u>prove</u></i> <b>VT</b> ...</span></span></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2023/06/ecg-blog-382-what-does-holter-show.html" target="_blank">ECG Blog #382</a></b> — Another case in which <b>Fusion</b> <i><u>confirms</u></i> <b>PVCs</b>.</span></span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-204-ecg-mp-22-bundle-branch.html" target="_blank">ECG Blog #204</a></b> — Reviews the ECG diagnosis of the <b>Bundle Branch Blocks (</b><i>RBBB/LBBB/IVCD</i><b>)</b>.</span><b> </b></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-203-ecg-mp-2021-axis.html " target="_blank">ECG Blog #203</a> </b>— Reviews ECG diagnosis of Axis and the <b>Hemiblocks</b>. For review of QRS morphology with the <b><i>Bifascicular</i></b> <b>Blocks (</b><i>RBBB/LAHB; RBBB/LPHB</i><b>)</b> — <i>See the </i><b><i><u>Video</u></i> Pearl</b> in this blog post.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2022/04/ecg-blog-301-40yo-man-vt-vs-aberrancy.html" target="_blank">ECG Blog #301</a></b> — Reviews a <b>WCT</b> that is <b><u>SupraVentricular</u>! (</b><i>with LOTS on Aberrant Conduction</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><br /></u></b></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2012/02/ecg-interpretation-review-38-wct-svt-vt.html" target="_blank">ECG Blog #38</a></b> <u>and</u> <b><a href="https://ecg-interpretation.blogspot.com/2014/03/ecg-interpretation-review-85-aberration.html" target="_blank">Blog #85</a></b> — Review of <b><i>Fascicular</i></b> <b>VT</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://tinyurl.com/KG-Blog-278" target="_blank">ECG Blog #278</a></b> — Another case of a <b><i>regular</i></b> <b>WCT</b> rhythm in a younger adult.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2012/01/ecg-interpretation-review-35-sct-vt.html" target="_blank">ECG Blog #35</a></b> — Review of <b><i>RVOT</i></b> <b>VT</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2012/05/ecg-interpretation-review-42-vt-brugada.html" target="_blank">ECG Blog #42</a></b> — Comprehensive review of criteria for distinguishing <b>VT</b> <u>vs</u> <b>Aberration</b>.</span></li></ul><div style="text-align: justify;"><div><span style="text-align: left;"><span><div style="text-align: justify;"><div><br /></div></div></span></span></div><div class="separator" style="clear: both; text-align: center;"><span><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div><div class="separator" style="clear: both; text-align: center;"><span><br /></span></div><div class="separator" style="clear: both; text-align: center;"><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"></div><span> <br /><div style="text-align: justify;"><div style="text-align: left;"><span><div style="text-align: justify;"><b><u><span face="Arial, sans-serif" style="color: red;">A</span></u></b><span face="Arial, sans-serif"><b style="text-decoration: underline;">DDENDUM</b><b> </b><b style="text-decoration: underline;"><span style="color: red;">(</span></b><i>2/17/2024</i><b><span style="color: red;">)</span>: </b></span></div></span></div></div></span></div></div></div></div></span><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><span><a href="https://dl.dropbox.com/s/769acsr94v5uj7b/z-ECG%20Audio%20Pearl-15%20Is%20VT%20Regular%20%282-24.1-2021%29-Faster.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1482" data-original-width="2048" height="290" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2hGOjeRVy2A14cJ-Izp3KsppyDMpupprWal1shocGP_dA0R56v7hlwwmt0icR5iGahFSbkwiqV3BibD2kBCU-WR4vJxXcLrAzmiuFExskayEnMuiQfWhfJ5cUWNOudZlTF4S1rNczfg8/w400-h290/MP-15+-+VT+Regular+%25282-24.1-2021%2529-USE.png" width="400" /></span> —</a></span></div><span><div style="text-align: justify;"><b style="font-style: italic;"><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>15 </b><b style="font-style: italic;">(</b><i>5 minutes </i><b><u style="font-style: italic;">Audio</u>)</b> — <i>Is</i> <b><i>Monomorphic</i></b> <i><b>VT</b> a regular rhythm?</i> — with attention to the 2 Caveats that emhasize how: <b>i<span style="color: red;">)</span></b> Fast AFib may look regular; <u>and</u>, <b>ii<span style="color: red;">)</span></b> <i>Monomorphic</i> VT is <i><u>not</u></i> always perfectly regular.</div><div style="text-align: justify;"><br /></div></span><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p></span></div><div><span style="font-family: arial; font-size: medium;"><div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></span><span><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span> </span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span><br /></span></p></div></span></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-16803387930398452472024-02-10T00:22:00.015-05:002024-02-10T12:44:29.912-05:00ECG Blog #416 — Is the Rhythm and ECG related? <span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Imagine the only information provided for the ECG in <u style="font-weight: bold;">Figure-1</u> — is that it was obtained from a 60-year old man with <b><i>new</i></b> <b>CP</b> <b>(</b><i><u>C</u>hest <u>P</u>ain</i><b>)</b>.</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>QUESTIONS:</u></b></span></div><div style="text-align: justify;"><ul><li>In view of this brief history —<i> How would YOU interpret</i> this ECG in <u>Figure-1</u>?</li><li><i>Is the cardiac rhythm </i><u style="font-style: italic; font-weight: bold;">related</u><b style="font-style: italic;"> </b><i>to the </i><b>12-lead ECG?</b></li></ul></div></span><div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOFsBe71_u8M4wsE5R9LdeYwgGRacHLU4yVuTbemoq8Xw7-lss0h70xQmejZaVyx8HjHnG65bmsQqXl2qCnzLpUEA9ErozAJvSR01ayV0XaEteKXVeaDs-Xwoua6_OSV0-vYZjchWs9bWnObwY1TfzkOC-6L16BLbtBaPE-PsZnvJOaiORNrk8KsLfrww/s3774/Figure-1%20%20ECG-1%20(12-21.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1674" data-original-width="3774" height="178" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiOFsBe71_u8M4wsE5R9LdeYwgGRacHLU4yVuTbemoq8Xw7-lss0h70xQmejZaVyx8HjHnG65bmsQqXl2qCnzLpUEA9ErozAJvSR01ayV0XaEteKXVeaDs-Xwoua6_OSV0-vYZjchWs9bWnObwY1TfzkOC-6L16BLbtBaPE-PsZnvJOaiORNrk8KsLfrww/w400-h178/Figure-1%20%20ECG-1%20(12-21.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-1:</u></b><span style="text-align: start;"> The <b><u style="font-style: italic;">initial</u> ECG</b> in today’s case.</span></span></td></tr></tbody></table><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>MY Thoughts</i> on the ECG in Figure-1:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">The <b><i><u>goal</u></i></b> of practicing clinicians is to interpret <b><i><u>both</u></i> parts </b>of the tracing in <u>Figure-1</u> <b>(</b> = <i>the cardiac rhythm <u>and</u> the 12-lead ECG</i><b>) </b>— in an <b>optimal <i>time-<u>efficient</u></i> manner</b>. </span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><span style="font-family: arial;">To accomplish the above goal — our interpretation of these </span><b style="font-family: arial;">2 Parts</b><span style="font-family: arial;"> of today’s tracing need </span><u style="font-family: arial;"><i>not</i></u><span style="font-family: arial;"> necessarily be complete on our initial assessment. </span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;">Instead — </span><b style="font-family: arial;">in an <i>acute</i> case such as today’s</b><span style="font-family: arial;"> </span><b style="font-family: arial;">(</b><span style="font-family: arial;">ie,</span><i style="font-family: arial;"> in which the patient presents for <u>new</u> CP</i><b style="font-family: arial;">)</b><span style="font-family: arial;"> — </span><b style="font-family: arial;">I favor spending <i>no more</i> than 5-to-10 seconds looking at the rhythm (</b><i style="font-family: arial;">to <u>ensure</u> that no immediate treatment is needed for this rhythm</i><b style="font-family: arial;">)</b><span style="font-family: arial;">. </span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;">I then </span><b style="font-family: arial;">turn my attention to the 12-lead ECG to assess whether an <i>acute</i> OMI is likely to be present</b><span style="font-family: arial;"> </span><b style="font-family: arial;">(</b><i style="font-family: arial;">in order to quickly determine IF prompt cardiac cath and potential PCI might be needed</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;"><br /></span></span></li><li><span style="font-family: arial; font-size: medium;"><span><u style="font-weight: bold;">PEARL <span style="color: red;">#</span></u><u style="font-weight: bold;">1:</u> Although I favor <i>limiting</i> the amount of time spent assessing today’s complex rhythm to <i><u>no</u> </i><u><i>more</i></u> than 5-to-10 seconds — I still favor using the <b><u style="font-style: italic;">systematic</u> <u>P</u>s, <u>Q</u>s, 3<u>R</u> Approach (</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a>) </b>because: <b>i<span style="color: red;">)</span></b> With minimal practice — you’ll find this systematic approach actually <i><u>speeds</u></i> <u>up</u> your assessment, rather than slowin</span><span>g it down; </span><u>and</u><span>, </span><b>ii<span style="color: red;">)</span> </b><span>Your </span><u><i>accuracy</i></u><span> in interpretation will improve </span><b>(</b><i>such that even if you do not arrive at a definitive diagnosis — you will <u>limit</u> diagnostic possibilities</i><b>)</b><span>.</span></span></li></ul><div><span style="font-family: arial; font-size: medium;"> </span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><i>My <span style="color: red;">Q</span>uick <span style="color: red;">A</span>ssessment </i>of Today’s Rhythm:</u></b></span></div><div><span style="font-family: arial; font-size: medium;">By the <b><u>P</u>s, <u>Q</u>s, 3<u>R</u> Approach:</b></span></div><div><ul><li><span style="font-family: arial; font-size: medium;">The rhythm in <u>Figure-1</u> is clearly <b><u style="font-style: italic;">not</u> <u>R</u>egular</b>. That said — it is supraventricular <b>(</b><i>because the </i><b><u>Q</u>RS complex</b> is <b><u style="font-style: italic;">not</u> wide)</b>. The overall <b><u>R</u>ate </b>is <u style="font-style: italic; font-weight: bold;">slow</u>, dropping in places to <u style="font-style: italic;">less</u> than 50/minute. <b><u>P</u> waves </b><u style="font-style: italic;">are</u> present — but the PR interval appears to be <u style="font-style: italic;">continually</u> changing <b>(</b>ie, <i>which raises the question as to whether <u>any</u> of the P waves are </i><b><u>R</u>elated </b><i>to neighboring QRS complexes</i><b><i>?</i>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">To EMPHASIZE:</u> The above <i>targeted</i> assessment by the <b>Ps,Qs,3R Approach</b> should <u style="font-style: italic;">not</u> take more than 10-20 seconds. <b>This is <u style="font-style: italic;">all</u> the information that you need</b> for an initial <u style="font-style: italic;">Quick</u> Assessment of the cardiac rhythm. </span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">NOTE:</u> Although the rate of the rhythm is quite slow in places — IF the patient is hemodynamically stable, then there is <u style="font-style: italic;">no</u> emergent treatment needed <b>(</b>ie,<i> There is <u>no</u> immediate need for a more precise interpretation of the rhythm</i><b>)</b>. This means that you can now turn your attention to the 12-lead ECG to determine IF prompt cath is (<i>or is not</i>) immediately needed in this patient with new CP.</span></li></ul><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;"><div><u style="font-weight: bold;"><br /></u></div>PEARL <span style="color: red;">#</span>2:</u><span> Looking first at the cardiac rhythm — I was <u style="font-style: italic;">not</u> initially sure IF some form of 2nd-degree AV block might be present. That said — <b>I <u style="font-style: italic;">instantly</u> knew </b>that today’s rhythm<b> was <u style="font-style: italic;">unlikely</u> to be complete AV block </b>because the ventricular response is so irregular!<b> </b></span><br /></span><ul><li><span style="font-family: arial; font-size: medium;">Most of the time when there is <b>complete (</b><i>3rd-degree</i><b>) AV block</b> — the ventricular response will be regular (<i>or at least <u>almost</u> regular</i>). This is beause IF <u style="font-style: italic;">none</u> of the P waves are able to conduct to the ventricles <b>(</b><i>as would be the case if complete AV block was present</i><b>)</b> — <b>a <i>regular</i> </b><b>escape focus (</b><i>either from the AV Node or from the ventricles</i><b>) </b>will usually take over the rhythm. The marked irregularity seen in <u>Figure-1</u> is simply too variable to arise from a normally functioning escape focus.</span></li></ul></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">==================================== </span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>Turning Attention to</i> the <span style="color: red;">1</span>2-<span style="color: red;">L</span>ead <span style="color: red;">E</span>CG:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">At this point in our interpretation — <i>We need to focus</i> on the <b>12-lead ECG</b>. I've highlighted in <u style="font-weight: bold;">Figure-2</u> the <i>KEY</i> leads that should capture your attention. In sequence, <b><i>over the next 20-to-30 seconds</i></b> — <u><i><b>your</b></i></u> <b>eye</b> should focus on the complexes within the <i>RED</i> — then <i>light BLUE </i>— then <i>dark BLUE</i> rectangles.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">In this patient with <b><i>new</i></b> <b>CP</b> — <i>What do YOU now <u>know</u>?</i></span></li><li><span style="font-family: arial; font-size: medium;"><i>What intervention is needed?</i></span></li><li><span style="font-family: arial; font-size: medium;">What does this tell us about the <i>likely etiology of</i> the rhythm?</span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgm8_JrCL9X2t8FUX2tTlBZPC3zZGoX4kPEqeQCFj9eiGWaUNSOA40lZZo-msv9TgppQiJQn8NMgAeLZ4eM07RGA4HNYBjcol6zEhgw5kS-K73s7RDqKSvHyn_2xAcQplX8IY3ALqUa_A0m4R3Nc4MN4_tXYF0InZ1R_u5dEYRRXjGt0YiZFlX_qe95iJo/s2242/Figure-2%20%20ECG-1%20(2-8.22-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="992" data-original-width="2242" height="178" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgm8_JrCL9X2t8FUX2tTlBZPC3zZGoX4kPEqeQCFj9eiGWaUNSOA40lZZo-msv9TgppQiJQn8NMgAeLZ4eM07RGA4HNYBjcol6zEhgw5kS-K73s7RDqKSvHyn_2xAcQplX8IY3ALqUa_A0m4R3Nc4MN4_tXYF0InZ1R_u5dEYRRXjGt0YiZFlX_qe95iJo/w400-h178/Figure-2%20%20ECG-1%20(2-8.22-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-2:</u></b><span style="text-align: start;"> I've highlighted the <i>KEY</i> complexes in the 12-lead ECG.</span></span></td></tr></tbody></table><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u>Interpretation of <i>Today’s</i> 12-Lead ECG:</u></b></span></div><div><span style="font-family: arial; font-size: medium;">In view of the history of <b><i>new</i> CP</b> — <i>YOUR</i> assessment of the 12-lead ECG in <u>Figure-2</u> should acknowledge the following:</span></div><div><ul><li><span style="font-size: medium;"><span style="font-family: arial;">Within the <u style="font-style: italic; font-weight: bold;">RED</u><b style="font-style: italic;"> </b><b>rectangle:</b><b style="font-style: italic;"> </b><b>— </b>The "shelf-like" flat ST segment with abrupt angulation into a prominent upright T wave in <b>lead V2</b> is immediately <i><u>diagnostic</u></i> of <b>acute <i><u>posterior</u></i> OMI (</b><i>where the <b>“O”</b> in “OMI” indicates an acute MI that is due to acute coronary <u style="font-weight: bold;">O</u>cclusion</i><b>)</b>. </span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;"><u style="font-weight: bold;">KEY <i>Clinical</i> Point:</u> Normally, there should be gentle upsloping of a slightly elevated ST segment in leads V2 and V3 — such that our "eye" should <i><u>immediately</u></i> recognize the abnormal <i><u>shape</u></i> of the complex within the <i>RED</i> rectangle <b>(</b><i>that tells us “posterior OMI” <u>until</u> proven otherwise</i><b>)</b>.</span><span style="font-family: arial;"> </span></span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial;"><span style="font-size: medium;">Within the <b><i>3 light <u>BLUE</u> </i>rectangles:</b> — Because of their common blood supply, posterior OMI is regularly associated with <i><u>inferior</u></i> OMI. Consequently — <i><u>confirmation</u></i> that the abnormal shape of the ST-T wave in lead V2 is <i>truly</i> the result of acute posterior OMI will be forthcoming IF limb leads are diagnostic of acute inferior MI. Note within each of the <i>light BLUE</i> rectangles — that there are <i>small-but-real</i> <b>Q waves</b> with <i>subtle-but-real</i> <b>ST elevation</b>. Especially in view of the modest QRS amplitudes — the ST-T wave in <b>lead III</b> clearly looks <b>hyperacute (</b>ie, <i>disproportionately "fatter"-at-its-peak and wider-at-its-base than it should be — with subtle terminal negativity of the T wave</i><b>)</b>.</span></span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial;"><span style="font-size: medium;">Within the <b><i>dark BLUE</i></b> <b>rectangle:</b> — The "magical" <i>mirror-image opposite</i> ST-T wave picture in <b>lead aVL</b> to that seen in lead III removes all doubt. Given tiny amplitude of the QRS in lead aVL — the disproportionate area within the depressed ST segment in this lead is a <b><i>reciprocal</i></b> <b>change</b> that <i><u>confirms</u></i> acute inferior OMI <b>(</b><i>Note terminal T wave positivity in lead aVL — that also reflects the mirror-image of the subtle terminal T wave negativity in lead III</i><b>)</b>.</span></span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial;"><span style="font-size: medium;"><u style="font-weight: bold;"><span style="color: red;">B</span>OTTOM <span style="color: red;">L</span>ine:</u> In <u style="font-style: italic;">less</u> than a minute — We can confirm that in today’s patient, who presents for evaluation with new CP — the ECG in <u>Figure-2</u> is diagnostic <i><u>until</u></i> proven otherwise, of <b>acute <i>infero-postero</i> OMI (</b><i>most likely from acute RCA occlusion</i><b>)</b>. <b>Prompt cath for PCI <i><u>is</u></i> clearly indicated!</b></span></span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial;"><span style="font-size: medium;"><b><u>PEARL <span style="color: red;">#</span>3:</u></b> An <i>advanced</i> clinical concept — is that acute inferior MI is commonly associated with 2nd-degree AV blocks of the Wenckebach (<i>Mobitz I</i>) type. Awareness of this common association made me instantly suspect that <b><i>some type of Wenckebach conduction</i></b> is probably operative in today's rhythm — even though I admittedly do <i><u>not</u></i> see any pattern of consistent group beating, or any repetitive PR intervals that typically clue me in to Mobitz I conduction defects.</span></span></li></ul></div><span style="font-family: arial; font-size: medium;">==============================</span></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>A <i>Closer</i> Look at <i><span style="color: red;">T</span>oday's</i> <span style="color: red;">R</span>hythm:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b>To Emphasize:</b> The important <i>"Take Home"</i> Message from today's case — is that in this patient with <i>new</i> CP — the ECG in <u>Figure-2</u> is diagnostic of <b>acute <i>infero-postero</i> OMI (</b><i>most likely from acute RCA occlusion</i><b>)</b> — and that <b><i>prompt</i></b> <b>cath</b> for <b>PCI</b> is needed.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Whatever the specific etiology of today's arrhythmia is, <b>the</b> <b><i>“good news”</i></b> is — that this rhythm will most probably improve with reperfusion of the "culprit" artery.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">That said — I found today's arrhythmia fascinating, and worthy of more in-depth analysis. <b>(</b><u style="font-weight: bold;">NOTE:</u><i> The laddergram solution I propose below for today’s rhythm is complex and clearly </i><b style="font-style: italic;"><u>Beyond</u>-the-Core</b><i>. That said — I believe my description and step-by-step construction of the </i><b>laddergram</b><i> below should prove insightful to any level provider.</i><b>)</b>.<i> </i></span></li><li><span style="font-family: arial; font-size: medium;"><i><br /></i></span></li><li><span style="font-family: arial; font-size: medium;">As a reminder — learning to draw laddergrams <u style="font-style: italic;">does</u> take some time and is <u style="font-style: italic;">not</u> needed to become experienced and skilled in clinical arrhythmia interpretation. But — <b>learning how to read laddergrams that are already drawn is </b><i><b>EASY </b>— </i>and <u style="font-style: italic;">all</u> clinicians <b>(</b><i>regardless of their level of experience</i><b>)</b> can quickly begin to benefit from the insight provided by laddergram illustration.</span></li><li><span style="font-size: medium;"><span style="font-family: arial;">For readers with an interest in learning <u style="font-style: italic;">either</u> how to read <i>and/or</i> draw laddergrams — I have added LINKS to more than 100 laddergrams (<i>many with step-by-step illustration</i>) at this site = </span><span style="font-family: arial; text-align: start;"><b><a href="https://tinyurl.com/KG-Laddergrams">https://tinyurl.com/KG-Laddergrams</a> </b>—</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><span style="text-align: justify;">==============================</span></span></div><div><span style="font-family: arial; font-size: medium;"><i>How to Proceed for “Solving” Today’s Arrhythmia:</i></span></div><div><span style="font-family: arial; font-size: medium;"><i>================================</i></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL<span style="color: red;"> #</span>4:</u> At this point — <b><i>Label the P waves!</i></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium; text-align: left;">The simple step of <b><i>labeling</i></b> <b>P waves</b> is tremendously helpful in visualizing potential relationships between atrial activity and neighboring QRS complexes.</span></li><li><span style="font-size: medium;"><span style="font-family: arial;"><span style="text-align: left;">Using <b><i><u>calipers</u></i></b> facilitates the process. I simply set my calipers at a P-P interval determined by selecting the distance between 2 P waves that I can identify with certainty. Because <b><i>"ventriculophasic"</i></b> <b>sinus arrhythmia</b> i</span></span><span style="font-family: arial; text-align: left;">s so commonly seen with 2nd- and 3rd-degree AV blocks — We need to factor in the reality that the P-P interval between sinus P waves will often vary slightly.</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i>Take a LOOK</i> at <u style="font-weight: bold;">Figure-3</u> — in which I've labeled sinus P waves with <i>RED arrows</i> throughout the rhythm strip.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Are any PR intervals the same?</span></li><li><span style="font-family: arial; font-size: medium;">Do you think any of the QRS complexes in <u>Figure-3</u> are being conducted? If so — <i>How can you tell</i> that P waves are conducting these QRS complexes<i>?</i></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiPeuojEqF_LoaF-pVmU8x8pUB6-A7x2yjlQebmk33NpEBRWLoMLcz-W1pSYH33sQsonSFg45phl2wb_5ACWaLngsVfNnSmfFbPF05m61ixvXlOe7SG-enbBburlskV6l-abfdF4EFl62KcflX-XUlrrEV8G2rbxDldqnCt5PvXZflqgvhMAQ1ZWMcCI0M/s3784/Figure-2%20ECG-1%20P%20Waves%20(12-21.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1686" data-original-width="3784" height="179" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiPeuojEqF_LoaF-pVmU8x8pUB6-A7x2yjlQebmk33NpEBRWLoMLcz-W1pSYH33sQsonSFg45phl2wb_5ACWaLngsVfNnSmfFbPF05m61ixvXlOe7SG-enbBburlskV6l-abfdF4EFl62KcflX-XUlrrEV8G2rbxDldqnCt5PvXZflqgvhMAQ1ZWMcCI0M/w400-h179/Figure-2%20ECG-1%20P%20Waves%20(12-21.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-3:</u></b><span style="text-align: start;"> I've labeled P waves with <i>RED</i> arrows.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><b><u><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></u></b></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>MY Thought</i>s on Figure-3:</u></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium; text-align: left;"><i>RED arrows</i> highlight a <b>fairly <i>regular</i> atrial rhythm</b> <b>(</b><i>with slight variation in the P-P interval due to ventriculophasic sinus arrhythmia</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium; text-align: left;">As noted earlier in PEARL #2 — today’s rhythm is <i><u>unlikely</u></i> to represent complete AV block. This is because of the marked irregularity of the ventricular rhythm <b>(</b><i>whereas complete AV block most often manifests a regular, or at least fairly regular ventricular rhythm</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium; text-align: left;">Most R-R intervals in the long lead II rhythm strip contain 2 P waves between QRS complexes — which means that <i>at least 1 of these P waves is <u>not</u> conducted</i>. This strongly suggests that the irregular rhythm in <u>Figure-3</u> represents <b><i>some</i> form of 2nd-degree AV block (</b>ie, <u style="font-style: italic;">either</u><i> </i><b>Mobitz I [</b><i> = AV Wenckebach</i><b>] </b><i>or </i><b>Mobitz II</b><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium; text-align: left;">IF this is true — then the fact that the QRS complex is narrow everywhere — that the PR interval is <i>not</i> constant — <u>and</u>, that the 12-lead ECG is diagnostic of an acute <i><u>infero</u>-postero</i> OMI — suggests <b><i>some</i></b> <b>form</b> <b>of</b> 2nd-degree <b>AV Wenckebach is operative (</b><i>because with Mobitz II — the PR interval is constant for consecutively conducted beats — the QRS is almost always wide, and anterior rather than inferior infarction has occurred</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium; text-align: left;">BUT — If the rhythm in <u>Figure-3</u> indeed represents some form of AV Wenckebach — it is <u style="font-style: italic;">not</u> a "typical" form of AV Wenckebach, because there is <u style="font-style: italic;">no</u> consistent pattern of group beating — <u>and</u>, similar PR intervals are lacking, whereas they are commonly seen with this Mobitz I form of 2nd-degree AV block. Instead — <b><i>the PR interval in front of each of the 9 beats in today's tracing is constantly changing</i></b> — which raises the question as to whether <u style="font-style: italic;">any</u> of the P waves are being conducted to the ventricles?</span></li></ul></div><div style="text-align: justify;"><span style="font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-size: medium;"><br /></span></div><div style="text-align: justify;"><i style="font-family: arial; text-align: left;"><span style="font-size: medium;">================================</span></i></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium; text-align: left;"><u style="font-weight: bold;">The <span style="color: red;">L</span>ADDERGRAM:</u> </span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium; text-align: left;">At this point I needed a laddergram to help me work out what might be a plausible mechanism for today's complex arrhythmia.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><span><u style="font-weight: bold; text-align: left;">NOTE:</u><span style="text-align: left;"> As I've commented on in a number of previous blog posts — Wenckebach conduction</span></span><span style="text-align: left;"> may occur at <i><u>more</u></i> than a single level within the AV Node. When this happens — complex conduction relationships may be seen, including non-conduction of consecutive <i>on-time</i> P waves <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-259-71-what-is-dual-level-block.html" target="_blank">ECG Blog #259</a></b><i> for more on </i><b><i><u>Dual</u>-Level </i>AV Wenckebach</b><i> — which is what I suspected in today's complex rhythm in which the PR interval constantly changes — and, in which 2 P waves are contained within most R-R intervals</i><b>)</b>.</span></span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium; text-align: left;"><i>================================</i></span></div><div style="text-align: justify;"><span style="font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhuiU6DMPTuHXnVt8IXJRRj6PNbDS0bOGmODN2cme637_xkgxSvrs61hWlDCjj3XNiJZOBKvGlzb06_IrOI5HPUYBzoSugelqKpnX578B6wVEMnztSyr2h8h5uqbtmAYCU5JlBUBBY1_dYemoxaVxmvrAdzMpZ1Cgv8tZOj7Fvzr2ABLtFTpbDA69mMLXQ/s3690/Figure-4%20-%20Ladder-1%20(12-21.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1506" data-original-width="3690" height="164" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhuiU6DMPTuHXnVt8IXJRRj6PNbDS0bOGmODN2cme637_xkgxSvrs61hWlDCjj3XNiJZOBKvGlzb06_IrOI5HPUYBzoSugelqKpnX578B6wVEMnztSyr2h8h5uqbtmAYCU5JlBUBBY1_dYemoxaVxmvrAdzMpZ1Cgv8tZOj7Fvzr2ABLtFTpbDA69mMLXQ/w400-h164/Figure-4%20-%20Ladder-1%20(12-21.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: start;"><u>Figure-4:</u></b><span style="text-align: start;"> </span></span><span style="color: #050505; font-family: arial; text-align: justify;">Laddergram <u>STEP-1</u>. It is usually easiest to begin a laddergram by filling in the <b><i>Atrial</i></b> <b>Tier</b>. <i>BLUE </i>arrows show the onset of P waves as my reference point for drawing in atrial activity. Because conduction through the atria is generally rapid — I drew in <i>near-vertical</i> lines in the Atrial Tier.<br /><u style="font-weight: bold;"><br />NOTE:</u> Because I suspected <b><i><u>dual</u>-level </i>AV block</b> within the AV Node — I divided the AV Nodal Tier into 2 parts by drawing in a horizontal <i>BLACK</i> <b><i>dotted line</i>)</b>.</span></span></td></tr></tbody></table></div><div><span style="font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div><span style="font-family: arial; font-size: medium; text-align: left;"><span style="caret-color: rgb(5, 5, 5); color: #050505; text-align: justify;"><br /></span></span></div></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWJAbWxaptiGlynDS-MKCXlAhjsljpdJoUa8JMj7OUBT6XSQBPrlNSPGUt_y5BSOQRzJetI_WzZImiYW_T_ufoGkGjiZvXWW5wahgyjD0lVJltNRlv14hvClqIi5d8GK-lSrGvSixV1_kXa71tKNgVSR-Qi4Nc8A2pwrCY-ltNmQUzDIGl0v89Y96avfo/s3676/Figure-5%20-%20Ladder-2%20(2-8.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1578" data-original-width="3676" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWJAbWxaptiGlynDS-MKCXlAhjsljpdJoUa8JMj7OUBT6XSQBPrlNSPGUt_y5BSOQRzJetI_WzZImiYW_T_ufoGkGjiZvXWW5wahgyjD0lVJltNRlv14hvClqIi5d8GK-lSrGvSixV1_kXa71tKNgVSR-Qi4Nc8A2pwrCY-ltNmQUzDIGl0v89Y96avfo/w400-h173/Figure-5%20-%20Ladder-2%20(2-8.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span><b style="font-family: arial; text-align: start;"><u>Figure-5:</u></b><span style="font-family: arial; text-align: start;"> </span></span><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">Laddergram </span><u style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">STEP-2</u><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">. I next fill in the </span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><i>Ventricular</i></b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> </span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">Tier</b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">. </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">BLUE</i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> arrows show the onset of each QRS complex as my reference point for each of the 9 supraventricular beats in this tracing. Once again, since conduction of narrow-QRS beats through the ventricles is generally rapid — I drew in <i>near-vertical</i> lines for each of the 9 narrow QRS beats in the Ventricular Tier.</span></span></td></tr></tbody></table><span style="font-size: medium;"><br /><span style="font-family: arial;"><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i>================================ </i></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="caret-color: rgb(5, 5, 5); color: #050505;"><u style="font-weight: bold;">NOTE:</u> The <i>"EASY part"</i> for constructing most laddergrams consists of these first 2 STEPS <b>(</b></span><i style="caret-color: rgb(5, 5, 5); color: #050505;">that are shown in Figure-4 and Figure-5</i><span style="caret-color: rgb(5, 5, 5); color: #050505;"><b>)</b>. </span></span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial;"><i>Now the challenge begins!</i></b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial;"> — with the task of trying to figure out</span><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial;"> </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial;"><u>which</u></i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial;"> of the P waves in the </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial;">Atrial</i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial;"> Tier are being conducted to the ventricles.</span></span></li><li><u style="font-family: arial; font-weight: bold; text-align: left;"><span style="font-size: medium;"><br /></span></u></li><li><span style="font-size: medium;"><u style="font-family: arial; font-weight: bold; text-align: left;">PEARL <span style="color: red;">#</span>5:</u><span style="font-family: arial; text-align: left;"> The </span><i style="font-family: arial; text-align: left;">BEST</i><span style="font-family: arial; text-align: left;"> clue that a P wave is conducting a QRS complex to the ventricles — is when, in association with an underlying sinus rhythm <b>(</b>ie, </span><i style="font-family: arial; text-align: left;">in which there are no PACs or PJCs</i><span style="font-family: arial; text-align: left;"><b>)</b> — you see a QRS complex that clearly occurs </span><i style="font-family: arial; text-align: left;">earlier-than-expected</i><span style="font-family: arial; text-align: left;">. This concept is best illustrated in </span><u style="font-family: arial; font-weight: bold; text-align: left;">Figure-6</u><span style="font-family: arial; text-align: left;">.</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><span style="font-family: arial; font-size: medium; text-align: left;"><i style="text-align: justify;">================================</i></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"> </span></span><br /></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><br /></span></span></div></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvFCOiITtoMQhlUFMVfV5zRx9-goEkF0cPNmCeo69gsSE8i-FjenNdZxPIaW8ki1L99JPeid1D7FnQUGvHNbhaPlYsZamVQJJEavcOXe9e5f03cT4bGZOmpOlqcy7bCYBsDddQLTDH6SKE2LZp2-JTma8Ny4Kv_iAEq5AW0gaACJayVWYmLLr7am2OKNw/s3698/Figure-6%20-%20Ladder-3%20(2-8.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1584" data-original-width="3698" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvFCOiITtoMQhlUFMVfV5zRx9-goEkF0cPNmCeo69gsSE8i-FjenNdZxPIaW8ki1L99JPeid1D7FnQUGvHNbhaPlYsZamVQJJEavcOXe9e5f03cT4bGZOmpOlqcy7bCYBsDddQLTDH6SKE2LZp2-JTma8Ny4Kv_iAEq5AW0gaACJayVWYmLLr7am2OKNw/w400-h173/Figure-6%20-%20Ladder-3%20(2-8.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><span style="text-align: justify;"><span><b style="text-align: start;"><u>Figure-6:</u></b><span style="text-align: start;"> </span></span></span><span style="text-align: left;">Of the 9 beats in </span><u style="text-align: left;">Figure-6</u><span style="text-align: left;"> — The QRS complex that most clearly occurs </span><i style="text-align: left;">earlier-than-expected</i><span style="text-align: left;"> is <b>beat #8</b>. By <i>PEARL #5</i> — <b>this suggests that beat #8 is a QRS complex that </b></span><u style="text-align: left;"><i><b>is</b></i></u><span style="text-align: left;"><b> being conducted to the ventricles</b>. Since beat #8 is <u style="font-style: italic;">neither</u> a PAC nor PJC <b>(</b><i>because the underlying sinus rhythm remains quite regular — and a PAC or PJC</i><i> would have reset the underlying sinus rhythm</i><b>)</b> — it must be that P wave <b>"n"</b> <u>is</u> conducting <b>beat #8</b>, albeit with a markedly prolonged PR interval <b>(</b><i>represented by the dark BLUE lines that pass through the 2 levels within the AV Nodal Tier</i><b>)</b>. <br /><br />P wave <b>"o"</b>, which falls right at the beginning of beat #8 — has <i>too short</i> of a PR interval to conduct <b>(</b><i>as I have represented by the light BLUE butt end that shows non-conduction of this impulse</i><b>)</b>.<br /></span></span></td></tr></tbody></table><span style="font-size: medium;"><br /><span style="font-family: arial;"><br /><span><br /></span></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjftWoZvybZSwYmCxUFwpkHFhwjBxB8Nta1QK9iYSsJ3lAE68MLqLYvsrioFx37rnIIHzQ8jY25jnnqx-aQUyRm5dCWrCZFoF_DSk9jyskQXix7dxsKdSbeYB8pHqXqMtMft0tJy5tDmX-Lw08poISZe34vJfAjNbs2_TSRKay68DZWd5iwcOw3Mgs-HOU/s3702/Figure-7%20-%20Ladder-4%20(2-8.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1570" data-original-width="3702" height="170" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjftWoZvybZSwYmCxUFwpkHFhwjBxB8Nta1QK9iYSsJ3lAE68MLqLYvsrioFx37rnIIHzQ8jY25jnnqx-aQUyRm5dCWrCZFoF_DSk9jyskQXix7dxsKdSbeYB8pHqXqMtMft0tJy5tDmX-Lw08poISZe34vJfAjNbs2_TSRKay68DZWd5iwcOw3Mgs-HOU/w400-h170/Figure-7%20-%20Ladder-4%20(2-8.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: start;"><u>Figure-7:</u></b><span style="font-family: arial; text-align: start;"> I fully acknowledge that because of the complexity of today's arrhythmia — some <i>"Trial and Error"</i> was needed along my way toward drafting the most logical solution to the laddergram for today's rhythm.<br /><br />The position of P wave <b>"l" (</b><i>occurring so soon after the previous QRS complex</i><b>)</b> — seemed extremely <u style="font-style: italic;">unlikely</u> to be conducting beat #7. This is especially true because P wave <b>"m"</b> appears in a much <i>better</i> position to conduct<b> beat #7</b>. I therefore drew in a <i>light BLUE butt end</i> to indicate <b><i>non-conduction</i></b> of P wave <b>"l"</b> — and <i>dark BLUE lines that pass through the 2 levels within the AV Nodal Tier to indicate conduction of </i>P wave <b>"m"</b>. Note that the incline of the <i>RED line</i> within the <i>lower</i> AV Nodal Tier is greater than the incline of the <i>dark BLUE line — </i><b>consistent with a PR interval that is <i>increasing</i> until P wave "o" is non-conducted.</b> <b>(</b><i>This makes for 3:2 AV Wenckebach conduction cycle within the AV Nodal Tier</i><b>)</b>.</span></span></td></tr></tbody></table><span style="font-size: medium;"><br /><span style="font-family: arial;"><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjThyphenhyphenU3Xwv3jyFs2Qgy7fyLv5OIPrDIou5COVG07cMhh5WuzfOoI40buLddoBRdQugypWdABOA06vIKSOCBzHqmiXQhrSLMXGbjZHLFJhEtoYPH9HVj_4o3sKFNFNpt4sLkMHZW-nr0ga-XPiFZl7M55sd4wmXrIdmvWpAIOzaKD-7zjOwgBzIsCXdcEUU/s3698/Figure-8%20-%20Ladder-5%20(2-8.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1576" data-original-width="3698" height="170" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjThyphenhyphenU3Xwv3jyFs2Qgy7fyLv5OIPrDIou5COVG07cMhh5WuzfOoI40buLddoBRdQugypWdABOA06vIKSOCBzHqmiXQhrSLMXGbjZHLFJhEtoYPH9HVj_4o3sKFNFNpt4sLkMHZW-nr0ga-XPiFZl7M55sd4wmXrIdmvWpAIOzaKD-7zjOwgBzIsCXdcEUU/w400-h170/Figure-8%20-%20Ladder-5%20(2-8.1-2024)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span><b style="text-align: start;"><u><span style="font-size: medium;">Figure-8:</span></u></b><span style="text-align: start;"><span style="font-size: medium;"> I next looked at P waves <b>"p"</b> and <b>"q"</b>. One of these 2 P waves will most probably be conducting <b>beat #9</b> to the ventricles. Because P wave <b>"q"</b> seems much better positioned to be conducting <b>(</b>ie, <i>with a slightly, but <u>not</u> excessively prolonged PR interval</i><b>)</b> — I felt reasonably sure that P wave <b>"p" </b>was <u style="font-style: italic;">not</u> conducting. <b>This meant that 2 P waves in a row</b> <b>(</b><i>P waves <b>"o"</b> and <b>"p"</b></i><b>)</b> <b>were <u style="font-style: italic;">not</u> conducting</b>. This finding supported my suspicion of <b><i><u>dual</u>-level</i></b> <b>AV block</b> within the AV Node, as the most logical explanation for there to be consecutive non-conducted P waves in a 2nd-degree AV block that is <u style="font-style: italic;">not</u> Mobitz II. <b>(</b><i>I show this non-conduction of P waves <b>"o"</b> and <b>"p"</b> by successive butt end RED lines at each of the 2 levels within the AV Nodal Tier</i><b>)</b>.</span><b><br /></b></span></span></td></tr></tbody></table><br /><span><br /></span></span></div><div><span style="font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqnttjyAnkVjbdYaWA88hB_Z4nbaJCRY3tkYEd7BrfRRW5quLnceuWjPWxxm7eGCqXAKPxoA9pDph_yIAIYAR_2epTI87-Evml0vzeF1d6FdSuPjdIzy6X6mDakTb-gpRE-cZVyawC4zrW5-y1hZt0XA79HsMTyz8ECbXPkduXOgoPjh5VR2kXNgqPCwk/s3698/Figure-8%20-%20Ladder-5%20(2-8.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1578" data-original-width="3698" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqnttjyAnkVjbdYaWA88hB_Z4nbaJCRY3tkYEd7BrfRRW5quLnceuWjPWxxm7eGCqXAKPxoA9pDph_yIAIYAR_2epTI87-Evml0vzeF1d6FdSuPjdIzy6X6mDakTb-gpRE-cZVyawC4zrW5-y1hZt0XA79HsMTyz8ECbXPkduXOgoPjh5VR2kXNgqPCwk/w400-h173/Figure-8%20-%20Ladder-5%20(2-8.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: start;"><u>Figure-9:</u></b><span style="font-family: arial; text-align: start;"> I next turned my attention to P waves <b>"j"</b> and <b>"k"</b>. Once again, it seems logical that 1 of these 2 P waves will probably be conducting <b>beat #6</b> to the ventricles. And once again, because P wave <b>"k"</b> seems much better positioned to be conducting <b>(</b>ie, <i>with a slightly, but <u>not</u> excessively prolonged PR interval</i><b>)</b> — I felt reasonably sure that P wave <b>"j"</b> was <u style="font-style: italic;">not</u> conducting. <b>(</b><i>This makes for a 2:1 AV conduction cycle — presumably by association being a 2:1 AV Wenckebach cycle</i><b>)</b>.</span></span></td></tr></tbody></table><span style="font-size: medium;"><br /><span style="font-family: arial;"><br /><br /><span><br /></span></span></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_xWhG05Pv4npc5SnFT_IWQ1YGFJNLuQ_DZeg99ikhnrLf6eKDf-B_2rEHo8gEPNVi8pp5GLTKHnwxjzyk0upUHQS7X0CLUnkKTPRyYQ3eiTReM-jFnIg4Yajb0MccfOUhFohXffr7qdeiPZyUoKxIIoe0UpX28SNd4HoXAwvm05ie9MPbOrVGdlLY25Q/s3704/Figure-10%20-%20Ladder-7%20(2-8.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1576" data-original-width="3704" height="170" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_xWhG05Pv4npc5SnFT_IWQ1YGFJNLuQ_DZeg99ikhnrLf6eKDf-B_2rEHo8gEPNVi8pp5GLTKHnwxjzyk0upUHQS7X0CLUnkKTPRyYQ3eiTReM-jFnIg4Yajb0MccfOUhFohXffr7qdeiPZyUoKxIIoe0UpX28SNd4HoXAwvm05ie9MPbOrVGdlLY25Q/w400-h170/Figure-10%20-%20Ladder-7%20(2-8.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: start;"><u>Figure-10:</u></b><span style="font-family: arial; text-align: start;"> At this point — <b><i>a <u>pattern</u> for conduction of atrial impulses seemed to be established</i></b>. By assessing atrial activity within <i>each</i> R-R interval — it became <i>easier</i> to intuit which P waves seemed <u style="font-style: italic;">least</u> likely to be conducting — therefore suggesting that the remaining P wave(s) were indeed conducting neighboring QRS complexes to the ventricles.<br /><br />P wave <b>"i"</b> seems perfectly positioned to conduct <b>beat #5</b> to the ventricles <b>(</b><i>in a similar way that P waves <b>"k"</b> and <b>"m"</b> seemed well positioned to be conducting <b>beat #6 </b>and <b>beat #7</b>, respectively</i><b>)</b>. IF this assumption is correct — then P waves <b>"g"</b> and <b>"h"</b> are <u style="font-style: italic;">not</u> conducting any QRS complex to the ventricles. As was the case for P waves <b>"o"</b> and <b>"p"</b> — this makes for 2 <i>non-conducted</i> P waves in a row <b>(</b><i>which is why I drew successive butt end BLUE lines for P waves <b>"g"</b> and <b>"h"</b> at each of the 2 levels within the AV Nodal Tier</i><b>)</b>.<br /><br /><i><b><u>Working my way backward</u></b></i> — I next noticed how much <i>earlier-than-expected</i> <b>beat #3</b> occurs, which as per <i>PEARL #5</i> — strongly suggests that <b>beat #3</b> <u style="font-style: italic;">is</u> being conducted to the ventricles. But the PR interval of P wave <b>"e"</b> until neighboring <b>beat #3</b> is clearly <i>too short</i> to conduct! Therefore, it <u style="font-style: italic;">must</u> <u>be</u> that P wave <b>"d"</b> is conducting <b>beat #3</b>, albeit with a very long PR interval <b>(</b><i>in the same way we deduced that P wave <b>"n"</b> is conducting <b>beat #8</b> with a long PR interval</i><b>)</b>.<br /><br />This left me with P waves <b>"b"</b> and <b>"c" </b>— which given the "pattern" of conduction observed up to this point, rendered it <i>EASY</i> for me to postulate that P wave <b>"c"</b> was much better positioned for conducting its neighboring QRS complex <b>(</b><i> = </i><b><i>beat #2</i>)</b> than P wave <b>"b"</b>.<br /><br /><b><u>Finally</u></b> — There is P wave <b>"a"</b> and <b>beat #1</b>. Although impossible to know for certain <b>(</b><i>because we do <u>not</u> see what happens before beat #1</i><b>)</b> — I drew in what seems to be the most logical conduction for this first part of today's rhythm <b>(</b><i>The PR interval between P wave <b>"a"</b> and <b>beat #1</b> clearly seems too short to conduct</i><b>)</b>.</span></span></td></tr></tbody></table><span style="font-size: medium;"><br /><span style="font-family: arial;"><br /></span></span></div><div><span style="font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><span><br /></span></span><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJM_knkXjRe0om3g5Idlr_RSjg2CK20N_anHtOD37tZakOIySPFkBSf-fNyQAMQLCkTLmggI3JZSs7GubmznlDiEB0lGXL_RurSTnm-OKMfgVDlPG-YsCZD9dMqU7kGzzygrq_d03hQjteVZrWwN8xOz5qp7Jz0OBt58SZk3ye-CfbCTUtr0YSox-PXL8/s3698/Figure-11%20-%20Ladder-8%20(2-8.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1580" data-original-width="3698" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJM_knkXjRe0om3g5Idlr_RSjg2CK20N_anHtOD37tZakOIySPFkBSf-fNyQAMQLCkTLmggI3JZSs7GubmznlDiEB0lGXL_RurSTnm-OKMfgVDlPG-YsCZD9dMqU7kGzzygrq_d03hQjteVZrWwN8xOz5qp7Jz0OBt58SZk3ye-CfbCTUtr0YSox-PXL8/w400-h173/Figure-11%20-%20Ladder-8%20(2-8.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: start;"><u>Figure-11:</u></b><span style="font-family: arial; text-align: start;"> My "finished" laddergram. Note that <u style="font-style: italic;">despite</u> the lack of similar groups of beats that repeat <b>(</b><i>and the <u>lack</u> of repetitive PR intervals</i><b>)</b> — <i>STEPPING</i> BACK from <u>Figure-11</u> <i>does</i> illustrate the concept of <b><i><u>dual</u>-level </i>AV Wenckebach</b>, in which there is progressive lengthening of PR intervals <b>(</b><i>represented by progressive increase in angulation within each of the 2 AV Nodal levels</i><b>)</b> — until 1 or 2 P waves in a row are dropped — <b>with typical <i>Wenckebach</i> periodicity beginning again <i>after</i> the brief pause</b>.</span></span></td></tr></tbody></table><span style="font-size: medium;"><br /></span></div><div><span style="font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div><i style="font-family: arial; text-align: justify;"><span style="font-size: medium;">================================</span></i></div><div><i style="font-family: arial; text-align: justify;"><span style="font-size: medium;"><br /></span></i></div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><b><u><span style="color: red;">F</span>inal <span style="color: red;">C</span>OMMENT:</u></b> </div><div style="text-align: justify;">Today's rhythm <u>is</u> difficult to interpret! That said — there are important lessons to be learned from review of today’s case.</div><div style="text-align: justify;"><ul><li>Precise determination of the etiology of today's arrhythmia is <i><u>not</u></i> needed for optimal initial management of today's patient! Instead — my <b><i>Quick </i>Assessment </b>of the rhythm<b> (</b><i>which should <u>not</u> take more than 10-20 seconds to complete</i><b>)</b> is all that is needed for optimal initial management of today's patient.</li><li>The <i>KEY</i> finding in today's ECG — is recognition in this patient with <i>new</i> CP that the tracing in <u>Figure-2</u> is <i>diagnostic</i> of <b>acute <i>infero-postero</i> OMI</b> — and that <b><i>prompt</i> cath is needed for PCI.</b></li><li>Whatever today's rhythm turns out to be — the "good news" is that the bradycardia and degree of AV block is likely to improve as soon as there is reperfusion of the "culprit" artery <b>(</b><i>Therefore need for prompt cath with PCI</i><b>)</b>.</li><li><br /></li><li>Being able to draw a laddergram of today's complex arrhythmia is <u style="font-style: italic;">not</u> essential for optimal initial management of today's patient. That said — it is good to be aware of the entity known as <b><i><u>dual</u>-level </i>AV Wenckebach </b>as a less common, but nevertheless important form of <b>2nd-degree AV block</b>. My hope is that review of my <i>step-by-step </i>approach to solving today's arrhythmia proves insightful for suggesting when <i>dual-level </i>AV Wenckebach should be suspected.</li><li>Learning to <u style="font-style: italic;">read</u> laddergrams that are drawn is <i>EASY</i>. Hopefully my <i>step-by-step</i> laddergram approach increases appreciation of the Wenckebach conduction pattern occurring in today's rhythm that is <u style="font-style: italic;">not</u> otherwise obvious.</li><li><br /></li><li>Finally — I will emphasize that my finished laddergram in <u>Figure-11</u> is <u style="font-style: italic;">not</u> the only possible solution to today's arrhythmia. More than a single solution is possible for many complex arrhythmias. What counts — is that my laddergram <u>is</u> a possible solution — and that some form of 2nd-degree AV block with periods of Wenckebach conduction <u>is</u> present.</li></ul></div></span><div><span style="font-size: medium;"><br /></span></div><div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==========================================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><span><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Adem Med Ahmed</span></span><span style="caret-color: rgb(5, 5, 5); color: #050505;"> (</span><i style="caret-color: rgb(5, 5, 5); color: #050505;">from Mauritania</i><span style="caret-color: rgb(5, 5, 5); color: #050505;">) and Ahmed Elbakery (<i>from Yemen</i>) for the case and this tracing.</span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==========================================</span></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><div class="separator" style="clear: both; text-align: justify;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"></a></span></div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></span><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></p></div><div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==============================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span>S</span>ystematic</i></b> <b><span>A</span>pproach</b> to 12-lead ECG Interpretation.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a> </b>— Reviews my System for <b><i>Rhythm</i></b> <b>Interpretation</b>, using the <b><u>P</u>s, <u>Q</u>s, 3<u>R</u> Approach</b>.</span></span></li><li style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> draw <b>L</b></span></span><span style="font-family: arial;"><b>addegrams </b></span><span style="font-family: arial;"><b>(</b><i>w</i></span><i style="font-family: arial;">ith LINKS to more than 100 laddergram cases — many with step-by-step sequential illustration</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" target="_blank">ECG Blog #192</a></b> — The <b>3 <i><u>Causes</u></i></b> of <b>AV Dissociation</b>.</span></li></ul><div style="text-align: justify;"><div><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><ul><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-191-ecg-mp-8-is-av-block.html" target="_blank">ECG Blog #191</a></b> — Reviews the difference between <b>AV Dissociation</b> <u>vs</u> <b><i>Complete</i> AV Block</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2023/08/ecg-blog-389-quote-from-sherlock-holmes.html" target="_blank">ECG Blog #389</a></b> — <b><a href="https://ecg-interpretation.blogspot.com/2023/04/ecg-blog-373-86yo-and-this-rhythm.html" target="_blank">ECG Blog #373</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-344-mobitz-i-mobitz-ii-or.html" target="_blank">ECG Blog #344</a></b> — for review of some cases that illustrate <b><i>"AV block problem-solving"</i></b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/09/ecg-blog-251-65-how-does-cycle-end.html" target="_blank">ECG Blog #251</a> </b><span>—</span><b> </b><span>Reviews the concepts of <b><i>Wenckebach</i></b> <b>periodicity</b> and the <b><i>"Footprints"</i></b> o</span></span>f Wenckebach.</li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2019/05/ecg-blog-164-pacs-blocked-pacs.html" target="_blank">ECG Blog #164</a></b><span> — Reviews a case of <i><u>typical</u></i> <b>Mobitz I 2nd-Degree AV Block (</b><i>with detailed discussion of the <b>"<span>F</span>ootprints"</b> of Wenckebach</i><b>)</b>. </span></span></li><li style="text-align: justify;"><span><br /></span></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2013/03/ecg-interpretation-review-63-av-block.html" target="_blank">ECG Blog #63</a> </b>— <b>Mobitz I, 2nd-Degree AV Block</b> with <b>Junctional <i>Escape</i> Beats.</b></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-267-75-group-beating-and.html" target="_blank">ECG Blog #267</a></b> — Reviews with <b><i>step-by-step</i></b> <b><u>laddergrams</u></b>, the derivation of a case of Mobitz I with more than a single possible explanation.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-259-71-what-is-dual-level-block.html" target="_blank">ECG Blog #259</a></b> — Reviews step-by-step laddergram for a patient with Dual-Level AV Block.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/07/ecg-blog-243-47-why-group-beating-av.html" target="_blank">ECG Blog #243</a></b><span> — Reviews a case of <b>AFlutter</b> with </span><b><i>Dual-Level</i></b><span> </span><b>Wenckebach</b><span> out of the </span><b>AV Node</b><span>.</span></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-226-42-variable-form-of.html" target="_blank">ECG Blog #226</a></b><span> — Works through a complex </span><b>Case Study (</b><i>including an 11:00 minute</i><span> </span><b>ECG</b><span> </span><b><i><u>Video</u></i></b><span> </span><b>Pearl</b><span> </span><i>that walks you through <b>step-by-step</b> in the construction of a <b>laddergram</b> with Wenckebach conduction and <u>dual</u>-level block within the AV node</i><b>)</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span>S</span>ystematic</i></b> <b><span>A</span>pproach</b> to 12-lead ECG Interpretation.</li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/04/ecg-blog-218-ecg-mp-35-what-is.html" target="_blank">ECG Blog #218</a></b> — Reviews <i>HOW</i> to define a <b><span>T</span> wave</b> as being <b><span>H</span>yperacute<span>?</span></b></span> </span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-193-ecg-mp-10-acute-omi.html" target="_blank">ECG Blog #193</a> </b>— Reviews the concept of why the term <b>“OMI” (</b> = <i><u>O</u>cclusion-based <u>MI</u></i><b>)</b> should <i><u>replace</u></i> the more familiar term STEMI — <u>and</u> — reviews the basics on how to <b><i>predict</i></b> the <b><i>"<u>culprit</u>" </i>artery</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2022/12/ecg-blog-351-posterior-leads.html" target="_blank">ECG Blog #351</a></b> — reviews the diagnosis of <b>acute <i><u>posterior</u></i> OMI</b></span><span style="font-family: arial; font-size: medium;">. To see this illustrative case presented as an <b><i>ECG</i> </b></span><b><u>Video</u></b><span style="font-family: arial;"> — Please check out </span><b><a href="https://ecg-interpretation.blogspot.com/2023/12/ecg-blog-406-to-do-additional-leads.html" target="_blank">ECG Blog #406</a></b><span style="font-family: arial;"> </span><b>(</b><span><i>For a LINKED Contents to this ECG Video — Click on MORE in the Description under the video on YouTube</i><b>)</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2023/11/ecg-blog-405-is-av-block-complete-vs-av.html" target="_blank">ECG Blog #405</a></b> — <b><i>ECG</i></b> <b><u>Video</u></b> presentation that reviews the distinction between <b>AV Dissociation</b> <i><u>vs</u></i> <b>Complete (</b><i>3rd-degree</i><b>) AV Block</b> </span><b>(</b><i>For a LINKED Contents to this ECG Video — Click on MORE in the Description under the video on YouTube</i><b>)</b><span style="font-family: arial;">.</span></li></ul><div><br /></div><div><br /></div></div></span></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"></div><span style="font-family: arial; font-size: medium;"> <br /><div style="text-align: justify;"><div style="text-align: left;"><span style="font-family: arial;"><div style="text-align: justify;"><b><u><span face="Arial, sans-serif" style="color: red;">A</span></u></b><span face="Arial, sans-serif"><b style="text-decoration: underline;">DDENDUM</b><b> </b><b style="text-decoration: underline;"><span style="color: red;">(</span></b><i>2/10/2024</i><b><span style="color: red;">)</span>:</b></span></div><div style="text-align: justify;"><span face="Arial, sans-serif"><b><br /></b></span></div></span></div><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; text-align: left;"></span></p><div><div style="text-align: center;"><span style="font-family: arial;"><br /></span></div><div style="text-align: center;"><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM6IE0axC-_2vJMD4d9lTnIIy2zqJZkybwADlcZyqs9SldX9AUMWa62snq9l2lgm14vb-Gtc47amXBkyV69cZd9C7oNg2BCBeRl64i1sHZm2e3DCYB5fs4bv04vDojyI5H7FabD9EOiu0/s2222/ECG-MP-52+-+2nd+Degree+AV+Blocks+%25286-24.1-2021%2529.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="462" data-original-width="2222" height="84" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM6IE0axC-_2vJMD4d9lTnIIy2zqJZkybwADlcZyqs9SldX9AUMWa62snq9l2lgm14vb-Gtc47amXBkyV69cZd9C7oNg2BCBeRl64i1sHZm2e3DCYB5fs4bv04vDojyI5H7FabD9EOiu0/w400-h84/ECG-MP-52+-+2nd+Degree+AV+Blocks+%25286-24.1-2021%2529.png" width="400" /></a></div></div><div style="text-align: center;"><span style="font-family: arial;"><br /></span></div><div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dxT-ku-l6xCxPPjBf7rI4tu3br2Ibz4fQVaRr8cywO9h_itaDDAliubOR0G5P3_t08hKiybw2-3nn4cfWkfBA' class='b-hbp-video b-uploaded' frameborder='0'></iframe></span></div><span style="font-family: arial;"><div style="text-align: justify;"><span>This <b>15</b>-minute <b>ECG Video (<span style="color: red;">M</span>edia <span style="color: red;">P</span>EARL <span style="color: red;">#</span>52)</b> — Reviews the <b>3 Types</b> of <b>2nd-Degree AV Block</b> — <u>plus</u> — the <i>hard-to-define</i> term of <b><i>"high-grade"</i></b> <b>AV block</b>. I supplement this material with the following 2 PDF handouts.</span></div><div style="text-align: justify;"><span><br /></span></div><div style="text-align: justify;"><span><br /></span></div><div style="text-align: justify;"><span><br /></span></div><div style="text-align: justify;"><span><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><div class="separator" style="clear: both;"><a href="https://dl.dropboxusercontent.com/s/p5o4fsrvt6mzqv3/z-ECG%20Audio%20Pearl-4%20%282-12.1-2021%29-USE-Faster.m4a?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1470" data-original-width="2048" height="288" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUAcJgawC2j9KDwKlACfTSKiiFHIo_a9sS0f1ZnbphiPfeBWj2mSS913KvLr_WX6iCOOpF-G8Bprw20u8pN73MMgyBaMr4Q21EXsDMgYLbRZSWW-bKbUSMQjiEFEj72JNPtxlA1iLfHe8/w400-h288/MP-4+%2528186%2529-Suspect+Mobitz+I-USE.png" width="400" /></span> —</a></div><br /></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial;"><span style="font-size: medium;"><b style="text-align: justify;"><u><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span><span>4</span></u></b><b style="text-align: justify;"> (</b><i><span style="text-align: justify;">4:3</span><span style="text-align: justify;">0</span></i><i style="text-align: justify;"> minutes <b><u>Audio</u></b></i><b style="text-align: justify;">)<span style="color: red;">:</span></b></span><span style="text-align: justify;"><span style="font-size: medium;"> — takes a brief look at the <b>AV Blocks</b> — and focuses on <i>WHEN</i> to <i>suspect</i> <b>Mobitz I</b>.</span><br /><br /></span></span></td></tr></tbody></table><span style="font-family: arial; text-align: left;"></span></span></div><div style="text-align: justify;"><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://www.dropbox.com/s/v01yvlqafd5c6z2/AV%20Blocks-Pg%2060-66%20ECG-PB%20%281-16.22-2021%29-USE.pdf?dl=0" target="_blank">Section 2F</a> (</b><i>6 pages = the <b>"<u>short</u>" Answer</b></i><b>)</b> from my ECG-2014 Pocket Brain book provides quick written review of the <b>AV Blocks</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><span><b><a href="https://www.dropbox.com/s/k1jk1y4o4uu48ab/20.0-%20ACLS-2013-e-PUB-AV%20Block-Dissociaton-%2810-15.11-2014%29-LOCK.pdf?dl=0" target="_blank">Section 20</a></b> </span><b>(</b><i>54</i><i> pages = the <b>"<u>long</u>" Answer</b></i><b>)</b> from my ACLS-2013-Arrhythmias <i>Expanded</i> Version provides <i>detailed</i> discussion of <i>WHAT</i> the <b>AV Blocks</b> are — and what they are <u>not</u>!</span></li></ul></div></span></div></div></div></div></span></div></div></div></div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span><br /></span></b></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropbox.com/s/zin2ybkqkudn2ck/z-ECG-Audio%20Pearl-71%20Dual-Level%20Wenckebach%20%2810-31.1-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1456" data-original-width="2048" height="285" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiIeNsyLy4ronKJHYOwiYzX9XbB6wZmYqj8qGWpOq4txbqwmvzRNvYXVGuHe8KSyMIiRox1aI6megxL6ZyLuIukrYBFVqCEs73fX3ab1Y_ZWm6P7_yt9VFr7kRWJGkJYwhXYlxO8iFEio/w400-h285/ECG-MP-71+Dual-Level+Wenckebach+%252810-31.1-2021%2529-USE.png" width="400" /></span> —</a></span></div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="font-family: arial; font-size: medium; text-align: left;"><i></i></span></span></p><p style="text-align: left;"></p><p></p><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>71 (</b><i>5:45 minutes</i> <b><i><u>Audio</u></i>)</b> — Reviews the phenomenon of <b><span style="color: red;">D</span>ual-<span style="color: red;">L</span>evel </b><b><span style="color: red;">W</span>enckebach </b><i><u>out</u> of</i> the <b>AV Node (</b><i>HOW to recognize this phenomenon — and how to distinguish it from Mobitz II</i><b>)</b>.</span></div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==============================</span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><b><span style="font-family: arial; font-size: medium;"><i>Free</i> <u><span style="color: red;">P</span>DF</u> <u><span style="color: red;">D</span>ownloads</u> from <i>relevant</i> Sections in my ECG-2014-ePub:</span></b></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"></span></p><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://www.dropbox.com/s/bfkhjrzqnnv1s2c/10.16-28-%20Coronary%20Circ-Culprit%20%282-10.23-2021%29-Lock-USE.pdf?dl=0" target="_blank">PDF File:</a></b> Overview on the Cardiac Circulation and the “Culprit” Artery in Acute MI —</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://www.dropbox.com/s/c9lrdwkz80gz9ol/10.33-%20ECG-2014-e-PUB-Post%20MI-Mirror%20Test-%2810-16.1-2014%29-LOCK.pdf?dl=0" target="_blank">PDF File:</a></b> Posterior MI and the “Mirror Test” —</span></li></ul><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; font-family: arial; margin: 0in; text-align: justify; white-space: normal;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; font-family: arial; margin: 0in; text-align: justify; white-space: normal;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; font-family: arial; margin: 0in; text-align: justify; white-space: normal;"><span style="font-family: arial; font-size: medium;"></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"></span></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkK-CI0tNg9si9WlGL0hEgd9TMBDJSMhJic0qBjw5ZB6SIYsl6pB_0RLF6rPCw7cWABoT_ferdPbfp8CAgbhCMp0R3ODWxbvAjzPGad8wqoAN3lIZ1XtdH3GDKxnsX4AWrfwCXWxvSH8g/s2048/Figure-3+ECG+Findings+to+Look+For+%25282-10.1-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1651" data-original-width="2048" height="323" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkK-CI0tNg9si9WlGL0hEgd9TMBDJSMhJic0qBjw5ZB6SIYsl6pB_0RLF6rPCw7cWABoT_ferdPbfp8CAgbhCMp0R3ODWxbvAjzPGad8wqoAN3lIZ1XtdH3GDKxnsX4AWrfwCXWxvSH8g/w400-h323/Figure-3+ECG+Findings+to+Look+For+%25282-10.1-2021%2529-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #333333;">Figure-12:</span></u></b><span style="color: #333333; text-align: justify;"> ECG findings to look for <b>when your patient</b> with <i>new-onset</i> cardiac symptoms <b>does <i><u>not</u></i> manifest <i>STEMI-criteria</i> ST elevation</b> on ECG. For more on this subject — <i>SEE the</i> <b><a href="http://hqmeded-ecg.blogspot.com/2020/08/omi-manifesto-lecture-in-20-minutes-via.html" target="_blank">September 3, 2020</a> post</b> in Dr. Smith’s ECG Blog with 20-minute video talk by Dr. Meyers on <b><i>The </i></b></span><b style="text-align: justify;"><i><span style="color: red;">O</span></i></b><b style="text-align: justify;"><i><span style="color: #333333;">MI </span></i></b><b style="text-align: justify;"><i><span style="color: red;">M</span></i></b><b style="text-align: justify;"><i><span style="color: #333333;">anifesto</span></i></b><span style="color: #333333; text-align: justify;">. For my clarifying Figure illustrating <b>T-QRS-D</b> (<i>2nd bullet</i>) — See <i><u>My</u> <u>Comment</u></i> at the <u>bottom</u> of the page in Dr. Smith’s <b><a href="http://hqmeded-ecg.blogspot.com/2019/11/a-50-something-with-left-shoulder-pain.html" target="_blank">November 14, 2019</a> post</b>.</span></span></td></tr></tbody></table><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropboxusercontent.com/s/tj2n20hmg0fuhj2/z-ECG%20Audio%20Pearl-10-OMI-Culprit%20%282-12.5-2021%29-USE-Faster.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1252" data-original-width="2048" height="245" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqqr9rDjZmLTqgW7bhmsiYB9L0uhZ8WTpJh0mdAUANMCzcgIa40oZ2eDCeW5NgPxfHFqhS9hMjZv3Ud8_fo7hF2pjfdJxm4uSfiHhCdjUaywDThjhh48gWNZMUMnyMLqCfb8HkY9SIY30/w400-h245/MP-10+%2528193%2529+OMI-+Culprit+Artery-USE.png" width="400" /></span> —</a></span></div><p class="MsoNormal" style="font-family: arial; margin: 0in; text-align: justify;"><span style="color: #333333; font-size: medium;"></span></p><p></p><p style="font-family: arial;"></p><div class="separator" style="-webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; clear: both; orphans: auto; text-align: center; white-space: normal; widows: auto;"><span style="text-align: left;"><div style="display: inline; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span>CG <span style="color: red;">M</span>edia <span style="color: red;">P</span>EARL <span style="color: red;">#</span>10 (</b>10 minutes <u>Audio</u><b>)</b> — reviews the concept of why the term <b>“OMI” (</b> = <i><u>O</u>cclusion-based <u>MI</u></i><b>) </b>should <i><u>replace</u></i> the more familiar term STEMI — <u>and</u> — reviews the basics on how to <b><i>predict</i></b> the <b><i>"culprit"</i></b> <b>artery</b>.</span></div></span></div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"></span></p><p class="MsoNormal" style="font-family: arial; margin: 0in; text-align: justify;"><span style="color: #333333; font-size: medium;"><br /></span></p><p class="MsoNormal" style="font-family: arial; margin: 0in; text-align: justify;"><span style="color: #333333; font-size: medium;"> </span></p><p class="MsoNormal" style="font-family: arial; margin: 0in; text-align: justify;"><span style="color: #333333; font-size: medium;"><br /></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjatWee2W48Bh23rkm3hVBpifsDfzqpN9-OjTIK4ekm14sEl2MRlkvCkOxtxMNVMFYAt07m0SNZmzaKDLeUpP0X8gXcl-Am4RJswxdfdywyAAFRHLkBvJu5KXkpl7ix9y9FKiUluxqsrY/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjatWee2W48Bh23rkm3hVBpifsDfzqpN9-OjTIK4ekm14sEl2MRlkvCkOxtxMNVMFYAt07m0SNZmzaKDLeUpP0X8gXcl-Am4RJswxdfdywyAAFRHLkBvJu5KXkpl7ix9y9FKiUluxqsrY/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><div class="separator" style="clear: both;"><span style="font-family: arial; font-size: medium;"><br /></span></div><span style="font-family: arial; font-size: medium;"><br style="text-align: left;" /></span><div class="separator" style="clear: both; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div class="separator" style="clear: both; font-family: arial; text-align: center;"><br /></div></div></div></div></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-8869763018672728052024-02-04T06:57:00.005-05:002024-02-04T07:15:05.393-05:00ECG Blog #415 — The Cath showed NO Occlusion!<span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;">Today’s patient is an older woman who experienced a number of fainting epiodes over the previous week. <i>No</i> CP (<i><u>C</u>hest <u>P</u>ain</i>). Shortly after arrival in the ED (<i><u>E</u>mergency <u>D</u>epartment</i>) — she suffered a <b><i>cardiac</i></b> <b>arrest</b>. The ECG in <span style="text-decoration: underline;">Figure-1</span> was obtained following successful resuscitation.</div></span><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><b><i>Stat</i></b> <b>Echo</b> — obtained shortly after successful resuscitation revealed anterior wall akinesis.</span></li><li><span style="font-family: arial; font-size: medium;">BUT — <b>Cardiac catheterization</b> done a little later did <span style="text-decoration: underline;"><i>not</i></span> reveal any significant stenosis.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>QUESTIONS:</u></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">In view of the above history — <i>How would YOU interpret</i> the ECG in <span style="text-decoration: underline;"><b>Figure-1</b></span>?</span></li><li><span style="font-family: arial; font-size: medium;">How can you <span style="text-decoration: underline;"><i>explain</i></span> that <i>no</i> “culprit” artery was found on cardiac catheterization?</span></li><li><span style="font-family: arial; font-size: medium;"><i>What is </i><b>T-QRS-D?</b> <i>Is this ECG finding present in today’s initial ECG?</i><i> </i></span></li></ul></div><div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzhZGpC4GTPPSbjjtNbGYivBtlmhpmiCQmjOJqbcJB_dnYg2LZmpWUoMlkVNM4Pp7tQ-JzzXYYkrArM2U9b6LoJQ5zsPxifNKUeCcRD1ADjGmYZMjZGFK0ud9NiReA9duAqDz3tTG6Nct8ZpX-GuFaTJsjSO5ujfibuwKxiDVJZpWxXZ1K49d5aiptnYA/s3780/Figure-1%20%20ECG-1%20%20(1-25.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1338" data-original-width="3780" height="141" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgzhZGpC4GTPPSbjjtNbGYivBtlmhpmiCQmjOJqbcJB_dnYg2LZmpWUoMlkVNM4Pp7tQ-JzzXYYkrArM2U9b6LoJQ5zsPxifNKUeCcRD1ADjGmYZMjZGFK0ud9NiReA9duAqDz3tTG6Nct8ZpX-GuFaTJsjSO5ujfibuwKxiDVJZpWxXZ1K49d5aiptnYA/w400-h141/Figure-1%20%20ECG-1%20%20(1-25.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><span><b style="text-align: start;"><u>Figure-1:</u></b><span style="text-align: start;"> </span></span><span style="text-align: start;">The <b><i><u>initial</u></i></b> <b>ECG</b> in today's case — obtained after successful resuscitation from cardiac arrest.</span><span><span style="text-align: start;"> </span></span><b>(</b><i>To improve visualization — I've digitized the original ECG using</i><span> </span><b><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span>.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><b><u><span style="font-family: arial; font-size: medium;"><i>MY Thoughts</i> on <i>Today’s</i> CASE:</span></u></b></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">Fortunately — Today’s patient was successfully resuscitated following her cardiac arrest. Despite the absence of significant coronary stenosis on her post-arrest cath — the ECG in </span><span style="text-align: left; text-decoration: underline;">Figure-1</span><span style="text-align: left;"> is clearly <i><u>diagnostic</u></i> of an <b>extensive <i><u>anterolateral</u></i> STEMI (</b><i>presumably from</i> <b><i>acute</i></b> <b>LAD [</b><i><u>L</u>eft <u>A</u>nterior <u>D</u>escending</i><b>]</b> <b>coronary artery occlusion)</b>.</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">The rhythm in </span><span style="text-align: left; text-decoration: underline;"><b>ECG #1</b></span><span style="text-align: left;"> is regular and supraventricular at a rate of ~75/minute. Although I do not clearly see sinus P waves in lead II (ie, <i>only the 1st beat seems to have an upright P wave in lead II</i>) — the QRS complex is narrow in all 12 leads, and a small, upright P wave with fixed PR interval </span><span style="text-align: left; text-decoration: underline;"><i>is</i></span><span style="text-align: left;"> seen in <b>lead V1 (</b><i>RED arrows in</i> </span><span style="text-align: left; text-decoration: underline;"><b>Figure-2</b></span><span style="text-align: left;"><b>)</b>.</span></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;">There is marked LAD (<i><u>L</u>eft <u>A</u>xis <u>D</u>eviation</i>) — with predominant negativity in lead II, consistent with LAHB (<i><u>L</u>eft <u>A</u>nterior <u>H</u>emi<u>B</u>lock</i>).</span></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;">No chamber enlargement.</span></span></li></ul></div><div style="text-align: justify;"><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="text-align: left;"><i>Regarding</i> </span><b><span style="text-align: left; text-decoration: underline;">Q</span><span style="text-align: left;">-</span><span style="text-align: left; text-decoration: underline;">R</span><span style="text-align: left;">-</span><span style="text-align: left; text-decoration: underline;">S</span><span style="text-align: left;">-</span><span style="text-align: left; text-decoration: underline;">T</span><span style="text-align: left;"> Changes:</span></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left; text-decoration: underline;"><b>Q</b></span><span style="text-align: left;"><b> Waves —</b> A very small, but somewhat widened Q wave of uncertain significance is seen in lead aVL. Tiny-but-present initial R waves are seen in each of the inferior leads (<i>consistent with LAHB — but <u>not</u> indicative of inferior infarction</i>).</span></span></li><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left; text-decoration: underline;"><b>R</b></span><span style="text-align: left;"><b> Wave Progression —</b> Although an initial R wave </span><span style="text-align: left; text-decoration: underline;">is</span><span style="text-align: left;"> seen in anterior leads V1,V2,V3 — there is </span><span style="text-align: left; text-decoration: underline;"><b>loss</b></span><b style="text-align: left;"> of R wave amplitude</b><span style="text-align: left;"> between lead V1-to-V2.</span></span></li><li><span style="font-family: arial; font-size: medium;"><b><span style="text-align: left; text-decoration: underline;">S</span><span style="text-align: left;">T-</span><span style="text-align: left; text-decoration: underline;">T</span></b><span style="text-align: left;"><b> Wave Changes —</b> The most dramatic change is the marked ST elevation that begins in lead V2 — and which remains substantial throughout the rest of the precordial leads. T waves in the inferior leads look <i>more-peaked-than-expected</i> given QRS amplitude in these leads — and there is <i>reciprocal</i> ST-T wave depression in lead aVL.</span></span></li><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">There is <b>T-QRS-D (</b><i><u>T</u>erminal <u>QRS</u> <u>D</u>istortion</i><b>)</b> in leads V4,V5,V6 <b>(</b><i>BLUE arrows in</i> </span><span style="text-align: left; text-decoration: underline;">Figure-2</span><span style="text-align: left;"><b>) </b>— <i>as discussed in detail below</i><b>)</b>.</span></span></li></ul></div><div style="text-align: justify;"><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></span></div><div style="text-align: justify;"><span style="text-align: left;"><b><u><span style="font-family: arial; font-size: medium;">IMPRESSION of <i>Today’s</i> ECG:</span></u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">As emphasized above — the post-arrest ECG in </span><span style="text-align: left; text-decoration: underline;">Figure-2</span><span style="text-align: left;"> is clearly diagnostic of an <b>extensive <i><u>anterolateral</u></i> STEMI</b>.</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">As best we can tell from the history we are given — this patient had syncope but </span><span style="text-align: left; text-decoration: underline;"><i>no</i></span><span style="text-align: left;"> CP prior to her acute event. As discussed in detail in <b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-228-44-what-is-main-problem.html" target="_blank">ECG Blog #228</a></b> — this seemingly qualifies as a <b><i>“</i></b></span><span style="text-align: left; text-decoration: underline;"><b><i>Silent</i></b></span><span style="text-align: left;"><b><i>”</i></b> <b>MI (</b><i>Approximately </i></span><i><span style="text-align: left; text-decoration: underline;">half</span><span style="text-align: left;"> of those MIs not accompanied by CP — have some </span><span style="text-align: left; text-decoration: underline;">other</span></i><span style="text-align: left;"><i> associated symptom such as syncope, which substitutes as a “chest pain equivalent”</i><b>)</b>.</span></span></li><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">The fact that cardiac cath performed shortly after cardiopulmonary resuscitation failed to reveal any significant coronary stenosis <b>(</b>ie, </span><span style="text-align: left; text-decoration: underline;"><i>No</i></span><span style="text-align: left;"><i> evidence of any “culprit” artery</i><b>)</b> — <i><b>qualifies <u>today's</u> case</b></i> as <b>MINOCA (</b> = <i><u>MI</u> with <u>N</u>on-<u>O</u>bstructive <u>C</u>oronary <u>A</u>rteries — which I discuss in detail below</i><b>)</b>.</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-style: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px;"><br /></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsMLY9Orewly6m6Gxz6mhuCTC9LcaWVyQ2Fr66z0T6QBHuBqIzhr3VRk2AGjd7YpsMjmCz8npNgtb4SUe9m2YLu3oVi-LDmIFrjEj0G1v5GibSbSAIW2E_h-p1CopENPxaCHO2o_8CJyOTVOjvw5smkL45SkV-L9lONCkzyW6ngOG_3_V3Rn9cMHDZGXM/s3766/Figure-2%20%20ECG-1-T-QRS-D%20%20(1-25.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1334" data-original-width="3766" height="141" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsMLY9Orewly6m6Gxz6mhuCTC9LcaWVyQ2Fr66z0T6QBHuBqIzhr3VRk2AGjd7YpsMjmCz8npNgtb4SUe9m2YLu3oVi-LDmIFrjEj0G1v5GibSbSAIW2E_h-p1CopENPxaCHO2o_8CJyOTVOjvw5smkL45SkV-L9lONCkzyW6ngOG_3_V3Rn9cMHDZGXM/w400-h141/Figure-2%20%20ECG-1-T-QRS-D%20%20(1-25.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: start;"><u>Figure-2:</u></b><span style="text-align: start;"> I've labeled <b><i>sinus</i></b> <b>P waves</b> in lead V1 — and <b>T-QRS-D</b> in leads V4,V5.</span></span></td></tr></tbody></table><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px;"><span style="font-family: arial; font-size: medium;"><br /></span></p></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">========================</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>What is</i> T-QRS-D?</u></b></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><span><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;">The concept of </span><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: red;"><i>T</i></span></b><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;"><i>erminal</i> </span></b><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: red;">Q</span></b><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;">RS </span></b><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: red;">D</span></b><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;">istortion (</span></b><b><i><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: red;">T-</span></i></b><b><i><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;">QRS</span></i></b><b><i><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: red;">-</span></i></b><b><i><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;">D</span></i></b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;"><b>) </b>was unknown to me<b> </b>p</span><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;">rior to becoming an Associate Editor in <a href="https://hqmeded-ecg.blogspot.com/" target="_blank"><b>Dr. Smith's</b> <b>ECG Blog</b></a>. Since then I've seen many clinical cases that validate this ECG finding promoted by Dr. Stephen Smith.</span></span></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><ul style="text-align: left;"><li style="text-align: justify;"><span style="background-color: #fefffe;"><b><span style="color: red;">T-</span><span style="color: #11053b;">QRS</span><span style="color: red;">-</span><span style="color: #11053b;">D</span></b><span style="color: #11053b;"> — is defined as the <i><u>absence</u></i> of <i>both</i> a <b>J-wave</b> <i>and</i> an <b>S-wave</b> in <b>lead V2</b> — <i>and/or</i> <b>lead V3</b> — <i>and/or</i> <b>lead V4 </b></span></span><span style="background-color: #fefffe;"><span style="color: #11053b;"><b>(</b><i>T-QRS-D may be seen in leads other than V2,V3,V4 — but its clinical significance when T-QRS-D is only seen in other leads is less certain</i><b>)</b></span></span><span style="background-color: #fefffe;"><span style="color: #11053b;">. </span></span></li><li style="text-align: justify;"><span style="background-color: #fefffe;"><span style="color: #11053b;"><u style="font-weight: bold;">NOTE:</u> T-QRS-D is simple to define. That said — <i>this ECG finding may be subtle!</i> I fully acknowledge that it has taken me some time to become comfortable and confident in its recognition</span></span><i style="background-color: #fefffe; color: #11053b;"><b>.</b></i></li><li style="text-align: justify;"><i style="background-color: #fefffe; color: #11053b;"><b><span style="caret-color: rgb(0, 0, 0); color: black; font-style: normal; font-weight: 400;"><span><span face=""arial" , sans-serif" style="background-attachment: scroll; background-clip: border-box; background-color: #fefffe; background-image: none; background-origin: padding-box; background-position: 0% 0%; background-repeat: repeat; background-size: auto; background: repeat rgb(254, 255, 254); color: #11053b;"><br /></span></span></span></b></i></li><li style="text-align: justify;"><i style="background-color: #fefffe; color: #11053b;"><span style="caret-color: rgb(0, 0, 0); color: black;"><span><span face=""arial" , sans-serif" style="background-attachment: scroll; background-clip: border-box; background-color: #fefffe; background-image: none; background-origin: padding-box; background-position: 0% 0%; background-repeat: repeat; background-size: auto; background: repeat rgb(254, 255, 254); color: #11053b;"><u style="font-weight: bold;">Clinical<span style="font-style: normal;"> Significance:</span></u><span style="font-style: normal;"> </span><span style="font-style: normal; font-weight: 400;">When present — </span><b style="font-style: normal; font-weight: 400;">T-QRS-D</b><span style="font-style: normal; font-weight: 400;"> may provide </span><i style="font-weight: 400;"><u>invaluable</u></i><span style="font-style: normal; font-weight: 400;"> assistance for distinguishing between a repolarization variant </span><u style="font-style: normal; font-weight: 400;">vs</u><span style="font-style: normal; font-weight: 400;"> acute OMI.</span><span style="font-style: normal; font-weight: 400;"> When true T-QRS-D is present in a patient with new symptoms — </span><span><b><span style="font-style: normal;">it is virtually </span><u>diagnostic</u><span style="font-style: normal;"> of </span>acute<span style="font-style: normal;"> OMI (</span></b></span><span style="font-style: normal; font-weight: 400;"> = </span><span style="font-weight: 400;">of an acute coronary <u>O</u>cclusion <u>M</u>yocardial <u>I</u>nfarction</span><span style="font-style: normal;"><b>)</b>.</span></span></span></span></i></li></ul><div style="margin-bottom: .0001pt; margin: 0in; text-justify: inter-ideograph;"><span style="font-family: arial;"><i><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;"><br /></span></i></span></div><div style="margin-bottom: .0001pt; margin: 0in; text-justify: inter-ideograph;"><span style="font-family: arial;"><b><i><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;">A picture is worth 1,000 words.</span></i></b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;"> </span></span><i style="background-color: #fefffe; color: #11053b;"><span style="caret-color: rgb(0, 0, 0); color: black;"><span><span face=""arial" , sans-serif" style="background-attachment: scroll; background-clip: border-box; background-color: #fefffe; background-image: none; background-origin: padding-box; background-position: 0% 0%; background-repeat: repeat; background-size: auto; background: repeat rgb(254, 255, 254); color: #11053b;"><span style="font-style: normal;">I i</span></span></span></span><span style="color: #11053b; font-style: normal;">llustrate the ECG finding of T-QRS-D below in </span><b style="font-style: normal;"><u>Figure-3</u></b><span style="color: #11053b; font-style: normal;">, which I've excerpted from </span><span style="color: #11053b;">My Comment</span><span style="color: #11053b; font-style: normal;"> i</span></i><i style="background-color: #fefffe; color: #11053b;"><span style="color: #11053b; font-style: normal;">n the </span><b style="font-style: normal;"><a href="http://hqmeded-ecg.blogspot.com/2019/11/a-50-something-with-left-shoulder-pain.html" target="_blank">November 14, 2019</a> post</b><span style="color: #11053b; font-style: normal;"> in Dr. Smith's ECG Blog. </span></i><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;">I’ve taken th</span><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);">e </span><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);">l</span></b><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);">ead </span></b><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);">V</span></b><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);">3</span></b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);"> examples in <b><u>Figure-3</u></b> from previous cases posted on Dr. Smith’s ECG Blog<b>:</b></span></div><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial;"><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);"></span><u><i><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);">T</span></b><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);">OP</span></b></i></u><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);"> in <u>Figure-3</u> — Despite the marked ST elevation in this <b>lead V3</b> — this is <i><u>not</u> </i>T-QRS-D, because there is <i>well-defined</i> <b>J-point notching (</b><i>BLUE arrow</i><b>)</b>. This patient had a repolarization variant as the reason for ST elevation<b>.</b></span></span></li><li style="text-align: justify;"><span style="font-family: arial;"><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);"><b> </b></span><u><i><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);">B</span></b><b><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);">OTTOM</span></b></i></u><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254);"> in <u>Figure-3</u> — This <u>is</u> <b>T-QRS-D</b>, because in this V3 lead there is <i><u>no</u></i> J-point notching — and, there is <i><u>no</u></i> S wave<b> (</b><i>RED arrow showing that the last QRS deflection never descends below the baseline to form an S wave</i><b>)</b><span style="color: #11053b;">.</span></span></span></li></ul></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjoac_t0ar4saTRunV7w_SOQz9pExLZwXYkppdiMVQK8DGNfcTqKChWd76_JhXbA9kFv7JZrBG3EXjJ_1c9Dwnc24LQS1XfVVHER53Mo4YhGEoq0drkX1l-TmrxBLhsnUIwgZsg_LwDd-R5PAnxk8Rn_6TUQkFgvPk0tk1626amEpBZFukE7oiMVtJ5/s1948/Figure-2%20%20T-QRS-D%20(6-27.22-2022)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1924" data-original-width="1948" height="395" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjoac_t0ar4saTRunV7w_SOQz9pExLZwXYkppdiMVQK8DGNfcTqKChWd76_JhXbA9kFv7JZrBG3EXjJ_1c9Dwnc24LQS1XfVVHER53Mo4YhGEoq0drkX1l-TmrxBLhsnUIwgZsg_LwDd-R5PAnxk8Rn_6TUQkFgvPk0tk1626amEpBZFukE7oiMVtJ5/w400-h395/Figure-2%20%20T-QRS-D%20(6-27.22-2022)-USE.png" width="400" /></a></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><span><b style="text-align: justify;"><u><span style="background-attachment: scroll; background-color: #fefffe; background-image: none; background-position: 0% 0%; background: repeat rgb(254, 255, 254); color: #11053b;">Figure-3:</span></u></b><b style="text-align: justify;"><span style="background-attachment: scroll; background-color: #fefffe; background-image: none; background-position: 0% 0%; background: repeat rgb(254, 255, 254); color: #11053b;"> </span></b><span style="background-attachment: scroll; background-color: #fefffe; background-image: none; background-position: 0% 0%; background: repeat rgb(254, 255, 254); color: #11053b; text-align: justify;">Comparison between ST elevation in lead V3 due to a <b><i>repolarization</i></b> <b>variant (</b><u>TOP</u> — <i>from</i> <a href="https://hqmeded-ecg.blogspot.com/2019/04/is-this-terminal-qrs-distortion-is.html" target="_blank"><b>4/27/2019</b></a><b>) </b>— <u>vs</u> <b><i>acute</i></b> <b>OMI (</b><u>BOTTOM</u> — <i>from</i> <a href="https://hqmeded-ecg.blogspot.com/2015/09/4-cases-discussing-terminal-qrs.html" target="_blank"><b>9/20/2015</b></a><b>)</b>, which manifests <b>T-QRS-D</b> (<i>See text</i>).</span></span></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><i style="text-align: justify;"><span face=""arial" , sans-serif" style="background-color: #fefffe; background: repeat rgb(254, 255, 254); color: #11053b;"><br /></span></i></span></div><div><span style="font-family: arial; font-size: large;">========================</span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><b><i>What is </i><span style="color: red;"><span style="caret-color: rgb(255, 0, 0);">M</span></span></b><b>INOCA?</b></span><span style="font-family: arial;"> </span></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;">I suspect the entity known as <b>MINOCA (</b><i><u>MI</u> with <u>N</u>on-<u>O</u>bstructive <u>C</u>oronary <u>A</u>rteries</i><b>)</b> — is <i><u>not</u></i> fully appreciated by many clinicians.</span></span></div><p style="font-family: arial; font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px; text-align: justify;"></p><ul style="font-family: arial; text-align: justify;"><li><span style="font-size: medium;">I was surprised to learn that <b>an <i>estimated</i> 5-15% of patients (</b><i>depending on the studied population</i><b>) who are diagnosed with <i><u>either</u></i> STEMI <u>or</u> NSTEMI — <i>turn out to have</i> MINOCA</b>, in which cardiac catheterization <i><u>fails</u></i> to reveal any <i>infarct-related</i> artery <b>(</b>ie, <i>no "culprit" vessel with at least 50% stenosis</i><b>)</b> — and <u style="font-style: italic;">no</u> clear systemic etiology is found to explain the patient's presentation to the hospital <b>(</b><i>Tamis-Holland et al: AHA Scientific Statement on MINOCA<span style="font-style: normal;"> — <b><a href="https://www.ahajournals.org/doi/pdf/10.1161/CIR.0000000000000670" target="_blank">Circulation 139:e891-e908, 2019</a></b></span> — Broncano et al — </i><b><a href="https://pubs.rsna.org/doi/epdf/10.1148/rg.2021200084" target="_blank">RadioGraphics 41:8-31, 2021</a></b> — <u>and</u> — <i>Sykes et al — </i><b><a href="https://www.icrjournal.com/node/14778" target="_blank">Interventional Card Review 16:e10, 2021</a>)</b>.</span></li></ul><div style="font-family: arial; text-align: justify;"><span style="font-size: medium;"><br /></span></div><div style="font-family: arial; text-align: justify;"><span style="font-size: medium;"><span><span>I was therefore intrigued by today's case — in which an older woman presented with syncope and cardiac arrest (<i>but no chest pain</i>) — with the ECG shown in <u>Figure-2</u> <b>(</b><i>as well as </i></span></span><i>anterior wall akinesis on Echo</i><b>)</b><span> —</span> but <u><b><i>without</i></b></u> any <b>obstructiv</b><b>e coronary disease on cardiac catheterization</b>.</span></div><div style="font-family: arial; text-align: justify;"><ul><li><span style="font-size: medium;">Because <i><u>all</u></i> emergency providers will periodically encounter MINOCA<b> (</b>ie, <i>the 5-15% estimated incidence of MINOCA that I cite above in patients initially diagnosed as having a STEMI or NSTEMI</i><b>)</b> — I've added <u style="font-weight: bold;">Figure-4</u>, which summarizes the more common entities associated with MINOCA <b>(</b><i>This Figure previously published in My Comment in the </i><b><a href="https://hqmeded-ecg.blogspot.com/2022/11/upon-arrival-to-emergency-department.html" target="_blank">November 30, 2022</a> post</b><i> in Dr. Smith's ECG Blog</i><b>)</b>.</span></li><li><span style="font-size: medium;"><span style="caret-color: rgb(51, 51, 51); color: #454545;">An </span><i style="caret-color: rgb(51, 51, 51); color: #454545;">all-too-common</i><span style="caret-color: rgb(51, 51, 51); color: #454545;"> misconception is that the absence of obstructive coronary disease on cardiac catheterization rules out acute coronary occlusion as the cause of the patient's acute event. </span><i style="caret-color: rgb(51, 51, 51); color: #454545;">This is <u>not</u> the case</i><span style="caret-color: rgb(51, 51, 51); color: #454545;">. </span><span style="caret-color: rgb(51, 51, 51); color: #454545;"><b>Non-obstructive coronary disease at the time cardiac cath is done does <u><i>not</i></u> necessarily imply there was no plaque rupture with thrombus</b>. This is because non-obstructive plaques can fissure, thrombose, totally (<i>or near totally</i>) occlude, have autolysis <b>(</b><i>spontaneous lysis of thrombus with reperfusion</i><b>)</b> — yet have <i>less</i> than 50% obstruction at angiography. </span></span></li><li><span style="font-size: medium;"><span style="caret-color: rgb(51, 51, 51); color: #454545;"><b><i>Such plaques will often <u>not</u> be recognized as "culprits"</i></b> — because no fissuring or ulceration is seen. As a result — determination of</span><span style="caret-color: rgb(51, 51, 51); color: #454545;"> plaque disruption in such patients can only be diagnosed by use of <b><i>intracoronary</i></b> <b>imaging</b> — with either <i>higher-resolution</i> <b>OCT (</b><i><u>O</u>ptical <u>C</u>oherence <u>T</u>omography</i><b>)</b> or <b>IVUS (</b><i><u>I</u>ntra<u>V</u>ascular <u>U</u>ltra<u>S</u>ound</i><b>)</b>.</span></span></li><li><u style="caret-color: rgb(51, 51, 51); color: #454545; font-weight: bold;"><span style="font-size: medium;"><br /></span></u></li><li><span style="font-size: medium;"><u style="caret-color: rgb(51, 51, 51); color: #454545; font-weight: bold;">KEY <i>Clinical </i>Point:</u><span style="caret-color: rgb(51, 51, 51); color: #454545;"> Despite lack of obstructive coronary disease on cardiac catheterization — <b><i>the most common cause of MINOCA is still probably an acute OMI that has spontaneously reperfused </i>(</b><i>but which is simply no longer evident by the time cardiac cath is performed</i><b>)</b>.</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div style="font-family: -webkit-standard; text-align: justify;"><b><u><span style="font-family: arial; font-size: medium;"><i>Additional</i> Points about MINOCA:</span></u></b></div><div style="font-family: -webkit-standard; text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="caret-color: rgb(51, 51, 51); color: #333333;">I found it surprising to learn that the initial description of acute MI <i>despite</i> normal coronary vessels is <i><u>not</u></i> a new concept — having been first described ~80 years ago </span><b style="caret-color: rgb(51, 51, 51); color: #333333;">(</b><i style="caret-color: rgb(51, 51, 51); color: #333333;">with eventual adoption of the term, "MINOCA" in 2013</i><b style="caret-color: rgb(51, 51, 51); color: #333333;">)</b><span style="caret-color: rgb(51, 51, 51); color: #333333;">.</span></span></div><div style="text-align: justify;"><ul style="font-family: -webkit-standard;"><li><span style="font-family: arial; font-size: medium;">The <b>3 most <i>common</i> Causes </b>of<b> ACS (</b><i><u>A</u>cute <u>C</u>oronary <u>S</u>yndrome</i><b>)</b> without coronary disease are: <b>i<span style="color: red;">)</span></b> Myocarditis (<i>up to 1/3 of these patients</i>); <b>ii<span style="color: red;">)</span> </b>Takotsubo cardiomyopathy; <u>and</u>, <b>iii<span style="color: red;">)</span></b> MINOCA.</span></li><li><span style="font-family: arial; font-size: medium;">There is a trend toward these patients being younger — with a greater relative percentage of women — and fewer traditional cardiac risk factors.</span></li><li><span style="font-family: arial; font-size: medium;">Longterm prognosis of patients with MINOCA clearly depends on the underlying etiology. That said — it's important to appreciate that this entity is <i><u>not</u></i> benign, with similar mortality as for patients with obstructive coronary disease following their infarction.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><b><i>Cardiac </i>MRI</b> — provides an answer to the etiology of patients with MINOCA in more than 2/3 of cases. </span></li><li><span style="font-family: arial; font-size: medium;">Cardiac MRI successfully identifies ~80% of patients with acute myocarditis by picking up evidence of inflammation — with the distinct advantage of being noninvasive compared to endomyocardial biopsy.</span></li><li><span style="font-family: arial; font-size: medium;">Use of <b>LGE (</b><i><u>L</u>ate <u>G</u>adolinium <u>E</u>nhancement</i><b>)</b> — is routinely recommended with cardiac MRI to increase diagnostic yield, as a means to identify fibrosis and other abnormalities in cardiac tissues.</span></li><li><span style="font-family: arial; font-size: medium;">Cardiac MRI (<i>especially with the addition of LGE</i>) provides insight to longterm prognosis of patients with MINOCA.</span></li></ul><div><br /></div></div></span></div></span></div><div><span style="font-family: arial; font-size: medium;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgnXL9CfE9ul-YhU_XabgT8N3D-NumYNpltyMfbgcpJdCbZmUOUndY03GhnyXoWkRAkbgGA_8JpV5hpHH9ij6LwrrN-5V4mWhzE5HWRI27HUiGj0n1ByLaKTFZJu2TqJrF2KTJ9GNhCLWHBnO9WDDrc0tEGW-xKj8ch5xayQ9fxWPvCUSuReCf7oVDdSI/s1416/Figure-4.%20Causes%20of%20MINOCA%20(2-4.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1416" data-original-width="1384" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjgnXL9CfE9ul-YhU_XabgT8N3D-NumYNpltyMfbgcpJdCbZmUOUndY03GhnyXoWkRAkbgGA_8JpV5hpHH9ij6LwrrN-5V4mWhzE5HWRI27HUiGj0n1ByLaKTFZJu2TqJrF2KTJ9GNhCLWHBnO9WDDrc0tEGW-xKj8ch5xayQ9fxWPvCUSuReCf7oVDdSI/w391-h400/Figure-4.%20Causes%20of%20MINOCA%20(2-4.1-2024)-USE.png" width="391" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><span style="font-family: arial;"><span style="color: #333333;"><b style="text-align: justify;"><u>Figur</u></b></span></span></span><span style="color: #333333; font-family: arial;"><b style="text-align: justify;"><u>e-4:</u></b><span style="text-align: justify;"> </span></span><span style="color: #333333; font-family: arial;">Classification of <b><i>Underlying</i></b> <b>Diagnoses</b> in Patients with <b>MINOCA</b> <b>(</b><i>Adapted from Table-1 in Sykes et al:</i> <b><a href="https://www.icrjournal.com/node/14778" target="_blank">Interventional Cardiology Review: 16:e10, 2021</a></b></span><b style="color: #333333;">)</b><span style="color: #333333; font-family: arial;">. <br /><br /><b><u>NOTE:</u></b> As per Sykes et al — The entities listed under <b><i>"<u>Other</u> Etiology"</i></b> may be diagnosed following further investigation <u>and</u> should be considered separately <b>(</b><i>because they are typically associated with myocardial injury but <u>not</u> considered an MI by the 4th universal definition of MI</i><b>)</b>. This is an <i><u>important</u></i> indication for <b><i>cardiac</i></b> <b>MRI</b> in patients suspected of MINOCA. <br /><br /><b><u>KEY <i>Clinical</i> Point:</u></b> </span><span style="caret-color: rgb(51, 51, 51); color: #454545; text-align: justify;">Despite lack of obstructive coronary disease on cardiac catheterization — </span><b style="caret-color: rgb(51, 51, 51); color: #454545; text-align: justify;"><i>the most common cause of MINOCA is still probably an acute OMI that has spontaneously reperfused </i>(</b><i style="caret-color: rgb(51, 51, 51); color: #454545; text-align: justify;">but which is simply no longer evident by the time cardiac cath is performed</i><b style="caret-color: rgb(51, 51, 51); color: #454545; text-align: justify;">)</b><span style="caret-color: rgb(51, 51, 51); color: #454545; text-align: justify;">.</span></span></td></tr></tbody></table></span></div><div style="text-align: center;"><br /></div><div><br /></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><span><span><span><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span style="font-size: medium;">==================================<o:p></o:p></span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-size: medium;"><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Arlind Dragoshi (<i>from Tirana, Albania</i>) for the case and this tracing.</span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span style="font-size: medium;">==================================<o:p></o:p></span></span></p><div style="text-align: justify;"> </div><div><span><span><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span><b><i><u>Related</u></i></b><b><u> ECG Blog Posts to <i>Today’s</i> Case: <o:p></o:p></u></b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><ul><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i>Systematic</i></b> <b>Approach</b> to 12-lead ECG Interpretation.</span> </span></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-183-repolarization-variant.html" target="_blank">ECG Blog #183</a></b> — Reviews the concept of <b><i>de<span>W</span>inter</i></b> <b><span>T</span></b><b>-</b><b><span>W</span></b><b>aves (</b><i>with reproduction of the illustrative Figure from the original deWinter NEJM manuscript</i><b>)</b>.</span></span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/04/ecg-blog-218-ecg-mp-35-what-is.html" target="_blank">ECG Blog #218</a></b> — Reviews <i>HOW</i> to define a <b><span>T</span> wave</b> as being <b><span>H</span>yperacute<span>?</span></b></span> </span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-193-ecg-mp-10-acute-omi.html" target="_blank">ECG Blog #193</a> </b>— Reviews the concept of why the term <b>“OMI” (</b> = <i><u>O</u>cclusion-based <u>MI</u></i><b>)</b> should <i><u>replace</u></i> the more familiar term STEMI — <u>and</u> — reviews the basics on how to <b><i>predict</i></b> the <b><i>"<u>culprit</u>" </i>artery</b>.</span></li><li style="text-align: justify;"><span><b><span style="color: #050505;"><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-194-ecg-mp-11-reperfusion-of.html" target="_blank">ECG Blog #194</a> </span></b><span style="color: #050505;">— Reviews how to tell IF the <b>“culprit” (</b>ie, <i>acutely occluded</i><b>)</b> artery has <i>reperfused</i> using clinical and ECG data.</span></span></li><li style="text-align: justify;"><span><span style="color: #050505;"><br /></span></span></li><li style="text-align: justify;"><span><span style="color: #050505;"><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-228-44-what-is-main-problem.html" target="_blank">ECG Blog #228</a></b> — Reviews the concept of <b><i>"Silent"</i></b> <b>MI</b>.</span></span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/04/blog-215-ecg-mp-32-at-least-4-notable.html" target="_blank">ECG Blog #215</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2022/07/ecg-blog-318-stroke-but-no-chest-pain.html" target="_blank">ECG Blog #318</a></b> — Review of cases with <b>T-QRS-D</b>.</span></li><li style="text-align: justify;"><span><br /></span></li><li style="text-align: justify;"><span>The <b><a href="http://hqmeded-ecg.blogspot.com/2019/11/a-50-something-with-left-shoulder-pain.html" target="_blank">November 14, 2019</a> post</b> in Dr. Smith’s ECG Blog <b>(</b><i>Please scroll down to the BOTTOM of the page for <b>My </b></i><b>Comment </b><i>and illustration of the phenomenon of</i> <b>T-QRS-D</b> = <i><u>T</u>erminal <u>QRS</u> <u>D</u>istortion</i><b>)</b>.</span></li><li style="text-align: justify;"><span>The <b><a href="http://hqmeded-ecg.blogspot.com/2023/11/what-does-angiogram-show-echo-ct.html" target="_blank">November 15, 2023</a> post</b> in Dr. Smith’s ECG Blog <b>(</b><i>See My </i>Comment<i> at the bottom of the page regarding </i><b><i>MINOCA</i>)</b>.</span></li></ul></span></span></div></span></span></span><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhwWHfM6W3aICHDBq3XV1KBPFXWb4j_daZbiX9_JuSjIedIyiURw73R0thZsA12obcGM2qeFUAkJ8tBiR2kN5VPT5m8HSiIlB3aNqVeWcwo4pKZJoDDnVhDDv_8XjfW_eI5O58nPSoPytOkKE2DnH3sIYwPDYkmNNIAFQ2DH-_20E56Kh6vTVTVqtdE=s613" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/a/AVvXsEhwWHfM6W3aICHDBq3XV1KBPFXWb4j_daZbiX9_JuSjIedIyiURw73R0thZsA12obcGM2qeFUAkJ8tBiR2kN5VPT5m8HSiIlB3aNqVeWcwo4pKZJoDDnVhDDv_8XjfW_eI5O58nPSoPytOkKE2DnH3sIYwPDYkmNNIAFQ2DH-_20E56Kh6vTVTVqtdE=w400-h16" width="400" /></a></span></div></div></div></span></div></span></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><span style="font-family: arial;"><br /><div><span style="color: #11053b;"></span></div></span></div><div style="text-align: justify;"></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"></div></span><div><div style="text-align: justify;"><div><div style="background-color: white; caret-color: rgb(51, 51, 51); color: #333333;"><div style="margin: 0in 0in 0.0001pt;"><div style="margin: 0in 0in 0.0001pt;"><div style="text-align: left;"><div style="margin: 0in 0in 0.0001pt; text-align: justify;"><br /></div></div></div></div></div></div></div></div></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-4712572569880404702024-01-26T19:35:00.031-05:002024-01-27T00:57:11.756-05:00ECG Blog #414 — What Kind of AV Block?<div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">I was sent the ECG in <b><u>Figure-1</u></b> — without the benefit of any history.</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>QUESTION:</u></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">What kind of AV block is present in <u>Figure-1</u>? </span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWfC7IkY1DXEYtn0M7QCGJHvazsiyVsXxO57p4VtprNlCFtynmwGtJtjWbNWvtpwVsQ5RuN8xMmb-7MrKyxG6jXLx3hZfjJyfEsHXIdfzMptMtaNBzOjPZ9YOMgdM3OZYmtgMRUcjE_6JRr8a2dUizxQ6ggVRJMrx2KSniiu1Zrviun3raIy5PBtgudaw/s3786/Figure-1%20%20ECG-1%20(1-21.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1934" data-original-width="3786" height="204" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWfC7IkY1DXEYtn0M7QCGJHvazsiyVsXxO57p4VtprNlCFtynmwGtJtjWbNWvtpwVsQ5RuN8xMmb-7MrKyxG6jXLx3hZfjJyfEsHXIdfzMptMtaNBzOjPZ9YOMgdM3OZYmtgMRUcjE_6JRr8a2dUizxQ6ggVRJMrx2KSniiu1Zrviun3raIy5PBtgudaw/w400-h204/Figure-1%20%20ECG-1%20(1-21.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial; text-align: start; text-decoration: underline;"><b>Figure-1:</b></span><span style="font-family: arial; text-align: start;"> The initial ECG in today's case.<span style="text-align: center;"><span style="text-align: start;"> </span></span><b style="text-align: center;">(</b><i style="text-align: center;">To improve visualization — I've digitized the original ECG using</i><span style="text-align: center;"> </span><b style="text-align: center;"><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span style="text-align: center;">.</span></span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><i>MY Approach </i>to Today’s Tracing:</u></b></span></div><div><span style="font-family: arial; font-size: medium;">As always — I favor beginning assessment with a quick look at the long lead rhythm strips at the bottom of the tracing. By the <b>Ps, Qs, 3R Approach (</b><i>which I review in </i><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a>):</b></span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><b><u>P</u></b> waves are present — and best seen in lead V1.</span></li><li><span style="font-family: arial; font-size: medium;">The <b><u>Q</u>RS</b> complex is narrow in all 12 leads.</span></li><li><span style="font-family: arial; font-size: medium;">The rhythm is <i><u>not</u></i> <b><u>R</u>egular</b>. The ventricular <b><u>R</u>ate</b> varies.</span></li><li><span style="font-family: arial; font-size: medium;">The 5th parameter of the Ps,Qs,3R Approach — is <b><i>the 3rd R</i></b>, which recalls <b>“<u>R</u>elated”</b> — or determining if P waves are (<i>or are not</i>) related to neighboring QRS complexes. This last parameter is best assessed by labeling P waves in the long lead V1 rhythm strip <b>(</b><i>which I have done in </i><b><u>Figure-2</u>)</b>.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u>QUESTIONS:</u></b></span></div><div><span style="font-family: arial; font-size: medium;"><i>Take a LOOK at</i> <u>Figure-2</u> — in which <i>RED arrows</i> highlight the <b>P waves</b>. </span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><i>How would YOU</i> describe the regularity (<i>or lack thereof</i>) of P waves in today's rhythm?</span></li><li><span style="font-family: arial; font-size: medium;">Are all of the P waves originating from the SA node?</span></li><li><span style="font-family: arial; font-size: medium;">Are all P waves conducted to the ventricles?</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjKgnUe8b7R2gpQ834jptBG3lC51p6EEPeleFbLrdJZx-UUzVLw94VhKYokuQ63gmX3S6dtFhtnMoYlEzf3_0o7u7YqJu1dbBfRYIMWtNPC7bk8t6AN7ZqHaqaIo8qVBTeVfY76mpPzKLneNnTBq5zWoqS8Hu7c8qSvJIXecEt1nWUAlRr9jH0k03XDAY/s3794/Figure-2%20%20ECG-1-%20P%20waves%20(1-21.22-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1938" data-original-width="3794" height="204" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjKgnUe8b7R2gpQ834jptBG3lC51p6EEPeleFbLrdJZx-UUzVLw94VhKYokuQ63gmX3S6dtFhtnMoYlEzf3_0o7u7YqJu1dbBfRYIMWtNPC7bk8t6AN7ZqHaqaIo8qVBTeVfY76mpPzKLneNnTBq5zWoqS8Hu7c8qSvJIXecEt1nWUAlRr9jH0k03XDAY/w400-h204/Figure-2%20%20ECG-1-%20P%20waves%20(1-21.22-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial; text-align: start; text-decoration: underline;"><b>Figure-2:</b></span><span style="font-family: arial; text-align: start;"> I have labeled <b>P waves</b> with <i>RED arrows</i> in today's rhythm.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><i>WHY are P waves so Irregular </i>in Figure-2?</u></b></span></div><div><span style="font-family: arial; font-size: medium;">Now that we have labeled all P waves in <u>Figure-2</u> with <i>RED</i> arrows — <i>Isn't it much <u>easier</u> to appreciate the irregular irregularity of the atrial rhythm?</i></span></div><div><ul><li><span style="font-size: medium;"><span style="font-family: arial;">Most of the time — it is lead II that provides best visualization of sinus P waves. That said — this is <u style="font-style: italic;">not</u> the case in today's rhythm, in that <b>lead V1</b> provides more consistent visualization of atrial activity in <u>Figure-2</u>.</span></span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div><span style="font-family: arial; font-size: medium;"><b><i>What We <u>Know</u> about the Rhythm ...</i></b></span></div><div><ul><li><span style="font-family: arial; font-size: medium;">At least <i>some</i> of the P waves in <u>Figure-2</u> appear to be <b><i>sinus</i> P waves</b> that <u>are</u> <b><i>conducted</i></b> to the ventricles — namely the P waves before <b>beats #3</b>,<b>7</b>,<b>8</b> and <b>9</b>. I say this because each of these beats is preceded by a <i>similar-looking</i> P wave with a <i>constant</i> and <i>normal</i> PR interval.</span></li><li><span style="font-family: arial; font-size: medium;">Other P waves are clearly <u style="font-style: italic;"><b>not</b></u> <b>conducted</b> to the ventricles — because the PR interval in front of <b>beats #1</b>,<b>2</b>,<b>5</b>,<b>6</b> and <b>11</b> appears to be <i>too short</i> to conduct. The fact that the R-R intervals that precede these beats are virtually the same <b>(</b>ie, <i>~5 large boxes in duration</i><b>)</b> — suggests that beats #1,2,5,6 and 11 are all <b>junctional <i><u>escape</u></i> beats</b> at an appropriate AV nodal escape rate of <b>~60/minute</b> <b>(</b>ie, <i>between the usual 40-60/minute range expected with junctional escape</i><b>)</b>.</span></li></ul><span style="font-family: arial; font-size: medium;"><div><span style="font-family: arial; font-size: medium;"><br /></span></div>I am <i>less</i> certain about the origin of<b> beats #4</b> and <b>10</b> — because these beats occur so much <i><u>earlier</u>-than-expected</i>. </span><br /><ul><li><span style="font-family: arial; font-size: medium;">The timing of beats #4 and 10 suggests that these beats may be <b>PACs (</b><i><u>P</u>remature <u>A</u>trial <u>C</u>ontractions</i><b>)</b>. Alternatively — it could be that each of the <i>RED arrow</i> P waves in <u>Figure-2</u> is a sinus P wave that occurs in association with a very <b>marked <i>sinus</i> arrhythmia</b>. </span></li><li><span style="font-family: arial; font-size: medium;">PACs typically manifest a different P wave morphology than sinus-conducted P waves, depending on how near or how far the site of the PAC is with respect to the SA node. For example, PACs arising from very close to the SA Node — may look very similar to sinus-conducted beats in most (<i>if not in all</i>) 12 leads.</span></li><li><span style="font-family: arial; font-size: medium;">Balanced with the above considerations regarding potential variation in P wave morphology — is the clinical reality that a certain amount of inherent variation in P wave morphology is common in sinus rhythms <b>(</b><i>See Pearl #6 in </i><b><a href="https://ecg-interpretation.blogspot.com/2024/01/ecg-413-pre-op-ecg-in-asx-patient.html" target="_blank">ECG Blog #413</a>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">BOTTOM Line:</u> I do <i><u>not</u></i> believe it possible to determine what the etiology of <b>beats #4</b> and <b>10</b> is with any certainty from <u>Figure-2</u>. We simply cannot tell from this single tracing if the slight variability in P wave morphology that we see in lead II (<i>not so much in lead V1</i>) is "real" <u style="font-style: italic;">vs</u> the effect of some normal variation in P wave morphology expected with sinus rhythms. </span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><i><u><span style="color: red;">P</span>utting <span style="color: red;">I</span>t <span style="color: red;">A</span>ll <span style="color: red;">T</span>ogether</u> </i><span style="color: red;">—</span></b> in a <b><span style="color: red;">L</span>addergram:</b></span></div><div><span style="font-family: arial; font-size: medium;">A picture "is worth 1,000 words" — so it's easier to illustrate the above description by means of a laddergram.</span></div><div><ul><li><span style="font-size: medium;"><span style="font-family: arial;">As I note above — it's <i><u>not</u></i> possible from this single tracing to determine with any certainty if <b>beats #4</b> and <b>10</b> represent PACs — <i><u>vs</u></i> participants in a <b><i>marked</i> sinus arrhythmia</b>. For the purpose of simplicity <b>(</b>ie, <i>of not having to assume the additional element of there also being PACs in today's rhythm</i><b>)</b> — I assumed all <i>RED arrow</i> P waves were sinus impulses <b>(</b>ie, <i><b>b</b></i></span><span style="font-family: arial;"><i><b>eats #3</b>,<b>7</b>,<b>8</b>,<b>9</b> — also being sinus-conducted beats</i><b>)</b>.</span></span></li><li><span style="font-family: arial; font-size: medium;"><b>Beats #1</b>,<b>2</b>,<b>5</b>,<b>6</b> and <b>11</b> represent <b>junctional <i><u>escape</u></i> beats</b> at an appropriate escape rate of <b>~60/minute (</b><i>the P waves occurring just before these beats manifesting a PR interval too short to conduct</i><b>)</b>.</span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><b><u>NOTE:</u></b> There is <b><i>transient</i></b> <b>AV dissociation</b> in today's rhythm — in the form of sinus P waves <u style="font-style: italic;">not</u> related to neighboring QRS complexes <b>(</b>ie, <i>the P waves before beats #1,2,5,6,11 manifesting a PR interval too short to conduct</i><b>)</b>. As discussed in detail in <b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" target="_blank">ECG Blog #192</a></b> — there are <b>3 Causes</b> of <b>AV Dissociation:</b> <b>i<span style="color: red;">)</span></b> By "default"; <b>ii<span style="color: red;">)</span></b> By "usurpation"; <u>and</u>, <b>iii<span style="color: red;">)</span></b> As a result of AV block. Regardless of whether there is marked sinus arrhythmia <u>vs</u> short pauses following PACs — the <u style="font-style: italic; font-weight: bold;">cause</u> of the transient AV dissociation seen in today's rhythm is a form of <i style="font-weight: bold;">"<u>default</u>" </i>— because the reason junctional escape beats #2,5,6 and 11 occur is a result of the slightly longer R-R intervals that precede each of these beats.</span></li><li><span style="font-family: arial; font-size: medium;">BUT — there is <b><u style="font-style: italic;">no</u> evidence of any AV block</b> in today's tracing — because we <i><u>never</u></i> see on-time sinus P waves that <i>should</i> conduct, yet fail to do so. </span></li><li><br /></li><li><span style="font-family: arial; font-size: medium;"><b><u>P.S.</u> (</b><i><u>Beyond</u>-the-Core</i><b>): </b>We were not provided with any history in today's case. Another possible explanation for today's rhythm might be a <b><i>marked increase</i> in vagal tone (</b><i>as per the case presented in </i><b><a href="https://ecg-interpretation.blogspot.com/2013/02/ecg-interpretation-review-61-av-block.html" target="_blank">ECG Blog #61</a>)</b> — which could result in not only marked sinus arrhythmia — but also some variation in the PR interval of sinus-conducted beats <b>(</b>ie, <i>It looks like the PR interval before conducted beats #4 and 10 may be slightly longer than the PR interval of other sinus-conducted beats</i><b>)</b>.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTuYrbq1y4Tvxn2i39oMR9VvVNiIuB7J8Gnp5sw5rquM1zT9m3uekfyD81FAp2fMWc9zye3l-KWzGWXaG4TBxHeJaWxtJpW6k6X9mSEB1Z6_LB6iApwWRykdqv9AIm2oGI-dXuxc9nmE70AW3B91dAQGriC6IIXm5rPbly9RNmeKyrEZG1W3SvrfapH60/s3682/Figure-3%20%20ECG-1%20Ladder%20(1-26.25-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1838" data-original-width="3682" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTuYrbq1y4Tvxn2i39oMR9VvVNiIuB7J8Gnp5sw5rquM1zT9m3uekfyD81FAp2fMWc9zye3l-KWzGWXaG4TBxHeJaWxtJpW6k6X9mSEB1Z6_LB6iApwWRykdqv9AIm2oGI-dXuxc9nmE70AW3B91dAQGriC6IIXm5rPbly9RNmeKyrEZG1W3SvrfapH60/w400-h200/Figure-3%20%20ECG-1%20Ladder%20(1-26.25-2024)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial; text-align: start; text-decoration: underline;"><b>Figure-3:</b></span><span style="font-family: arial; text-align: start;"> Laddergram illustration for today's rhythm. The laddergram suggests there is <b><i>marked</i> sinus arrhythmia</b> — that results in <b><i>transient</i></b> <b>AV dissociatio</b>n by <b><i>"default"</i></b> because junctional "escape" beats #1,2,5,6,11 occur <i>before</i> the delayed sinus impulses have an opportunity to conduct. The <b>junctional <i>escape</i> rhythm</b> is set at ~60/minute, such that these junctional escape beats are appropriate <b>(</b><i>and do <u>not</u> represent any form of AV block! </i><b>)</b>.</span></span></td></tr></tbody></table></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><div><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;">==========================================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><span><span><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Danilo Franco</span></span><span style="caret-color: rgb(5, 5, 5); color: #050505;"> (</span><i style="caret-color: rgb(5, 5, 5); color: #050505;">from Italy</i><span style="caret-color: rgb(5, 5, 5); color: #050505;">) for the case and this tracing.</span></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;">==========================================</span></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><div class="separator" style="clear: both;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"></a></span></div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></span><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span></p></div><div><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;">============================== <o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></p><p class="MsoNormal" style="margin: 0in;"></p><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a> </b>— Reviews my System for <b><i>Rhythm</i></b> <b>Interpretation</b>, using the <b>Ps</b>, <b>Qs & 3R Approach</b>.</span></span></li><li style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> <i>draw</i> <b>Laddergrams</b></span></span><span style="font-family: arial;"><b> </b></span><span style="font-family: arial;"><b>(</b><i>w</i></span><i style="font-family: arial;">ith LINKS to more than 90 laddergram cases — many with step-by-step sequential illustration</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" target="_blank">ECG Blog #192</a></b> — The <b>3 <i><u>Causes</u></i></b> of <b>AV Dissociation</b>.</span></li></ul><div><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><ul><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-191-ecg-mp-8-is-av-block.html" target="_blank">ECG Blog #191</a></b> — Reviews the difference between <b>AV Dissociation</b> <u>vs</u> <b><i>Complete</i> AV Block</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2023/08/ecg-blog-389-quote-from-sherlock-holmes.html" target="_blank">ECG Blog #389</a></b> — <b><a href="https://ecg-interpretation.blogspot.com/2023/04/ecg-blog-373-86yo-and-this-rhythm.html" target="_blank">ECG Blog #373</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-344-mobitz-i-mobitz-ii-or.html" target="_blank">ECG Blog #344</a></b> — for review of some cases that illustrate <b><i>"AV block problem-solving"</i></b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-267-75-group-beating-and.html" target="_blank">ECG Blog #267</a></b> — Reviews with <b><i>step-by-step</i></b> <b><u>laddergrams</u></b>, the derivation of a case of Mobitz I with more than a single possible explanation.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2013/02/ecg-interpretation-review-61-av-block.html" target="_blank">ECG Blog #61</a></b> — <b><i>Vagotonic</i></b> <b>block</b>. </li></ul><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div><div><br /></div></div></span></span></div></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-86158592562515608102024-01-20T08:31:00.005-05:002024-02-09T21:58:24.960-05:00ECG #413 — A Pre-Op ECG in an ASx Patient<div><span style="font-family: arial; font-size: medium;"><br /></span></div><span style="font-size: medium;"><div style="font-family: arial; text-align: justify;"><span style="text-align: left;">I was sent the tracing shown in </span><span style="text-align: left; text-decoration: underline;"><b>Figure-1</b></span><span style="text-align: left;"> — told only that this was a preoperative ECG obtained from an <i>asymptomatic</i> older woman scheduled for <i>non-cardiac</i> surgery.</span></div><div style="font-family: arial; text-align: justify;"><ul><li><span style="text-align: left;"><i>How would YOU interpret </i>this ECG?</span></li><li><span style="text-align: left;">Would you <i><u>approve</u></i> her for surgery if the procedure was nonemergent?</span><span style="text-align: left;"> </span> </li></ul></div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUMYjsMLOayfZLH3ZC2KbE9M0gElYTg_TY4if6aZ-buoESCSPueqh5lg0beC11wZAyBLz3zxi5URW4UOgHjhPdfXfE_Q3lWRk06nJnVUHd97WbJNLmBP0LqdDCQbnJV_5m_AqcQtx5sRnC3HJB9h51-81IvqaCqHcIndblT3XeUdiQS3hYODyX55D5RO8/s3796/Figure-1%20%20ECG-1%20(1-13.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="2058" data-original-width="3796" height="216" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjUMYjsMLOayfZLH3ZC2KbE9M0gElYTg_TY4if6aZ-buoESCSPueqh5lg0beC11wZAyBLz3zxi5URW4UOgHjhPdfXfE_Q3lWRk06nJnVUHd97WbJNLmBP0LqdDCQbnJV_5m_AqcQtx5sRnC3HJB9h51-81IvqaCqHcIndblT3XeUdiQS3hYODyX55D5RO8/w400-h216/Figure-1%20%20ECG-1%20(1-13.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span><span><b style="text-align: justify;"><u>Figure-1:</u></b><span style="text-align: justify;"> </span></span>Preoperative ECG from an asymptomatic older woman scheduled for non-cardiac surgery. <i>Would you approve her for a nonemergent surgical procedure? </i></span><b>(</b><i>To improve visualization — I've digitized the original ECG using</i><span> </span><b><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span>.</span></span></td></tr></tbody></table><div style="font-family: arial;"><br /></div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><b style="text-decoration: underline;">MY <i>Initial</i> Thoughts on <i>Today’s</i> CASE:</b></div><div style="font-family: arial; text-align: justify;">This patient should <span style="text-decoration: underline;"><i>not</i></span> be approved for <i>non-emergent</i> surgery.</div><div style="font-family: arial; text-align: justify;"><ul><li>Looking first at the <b>long-lead II <i>rhythm</i> strip</b> — there is <b><i>significant</i></b> <b>bradycardia</b>, with a heart <span style="text-decoration: underline;"><b>R</b></span>ate just <b>under 40/minute</b>. The <span style="text-decoration: underline;"><b>Q</b></span><b>RS</b> complex is <b><i>narrow</i></b> in all 12 leads — so the rhythm is supraventricular. </li><li>The overall ventricular response looks <span style="text-decoration: underline;"><b>R</b></span>egular.</li><li><span style="text-decoration: underline;"><b>P</b></span> waves <span style="text-decoration: underline;">are</span> present — but they seem to be <b><i>un</i></b><span style="text-decoration: underline;"><b><i>R</i></b></span><b><i>elated</i></b> to neighboring QRS complexes <b>(</b>ie, <i>The PR interval varies — at the least, for some of the beats</i><b>)</b>.</li><li><br /></li><li><span style="text-decoration: underline;"><b>BOTTOM Line:</b></span> Since many of the P waves in this long lead II rhythm strip occur at points within the R-R interval where they appear to have <span style="text-decoration: underline;"><i>more</i></span> than ample opportunity to conduct — <i>yet still fail to do so</i> — some form of <b>2nd-degree (</b><i>if not, 3rd-degree</i><b>) AV block</b> is present, in association with <b><i>marked</i> bradycardia</b>.</li></ul></div><div style="font-family: arial; text-align: justify;"><b style="text-decoration: underline;"><br /></b></div><div style="font-family: arial; text-align: justify;"><b style="text-decoration: underline;">Comment:</b></div><div style="font-family: arial; text-align: justify;"><ul><li><span style="text-decoration: underline;"><b>PEARL <span style="color: red;">#</span>1:</b></span> I arrived at the above initial thoughts on today’s rhythm <b><span style="text-decoration: underline;"><i>within</i></span> seconds</b> of seeing the long lead II rhythm strip. Stressing this aspect of how <b><i>time-efficiency</i></b> in rhythm diagnosis may facilitate rapid clinical decision-making — is one of my primary objectives in writing this ECG Blog <b>(</b>ie, <i>the surgeon in today’s case may be waiting on your interpretation of this “routine” pre-op ECG before proceding</i><b>)</b>. </li><li><span style="text-decoration: underline;"><b>PEARL <span style="color: red;">#</span>2:</b></span> The <i>KEY</i> for optimal time-efficiency — is to use a <span style="text-decoration: underline;"><i>systematic</i></span> approach that addresses the <b>5 parameters</b>, which are easily recalled by the phrase, <b>“<i>Watch your </i></b><span style="text-decoration: underline;"><b><span style="color: red;">P</span></b></span><b>s, </b><span style="text-decoration: underline;"><b><span style="color: red;">Q</span></b></span><b>s <i>and the</i> 3</b><span style="text-decoration: underline;"><b><span style="color: red;">R</span></b></span><b>s”</b> <b>(</b><i>See</i> <b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a> </b><i>for review of this system</i><b>)</b>.<span style="color: #2e2d33;"> Applying the Ps,Qs,3Rs <b><i>tells us </i></b></span><span style="color: #2e2d33; text-decoration: underline;"><b><i>within</i></b></span><span style="color: #2e2d33;"><b><i> seconds</i></b> that this 70-year old woman should </span><span style="color: #2e2d33; text-decoration: underline;"><i>not</i></span><span style="color: #2e2d33;"> be approved for non-emergent surgery.</span></li></ul></div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><div><b style="text-decoration: underline;"><i>What About</i> the <span style="color: red;">1</span>2-<span style="color: red;">L</span>ead <span style="color: red;">E</span>CG?</b></div><div><span>While our brief assessment of the rhythm in today's case is enough to merit canceling this patient's non-emergent surgery — <i>there is more!</i></span></div><div><ul><li><b><i>The 12-lead ECG is very concerning</i></b>. Although we only see 1 or 2 beats in each lead <b>(</b><i>because the heart rate is so slow</i><b>)</b> — there is ST segment straightening with slight depression, that appears to be <b><i>maximal</i></b> in <b>lead V3 (</b><i>especially noteworthy since normally there is slight ST <u>elevation</u> in this lead!</i><b>)</b>. ST segment straightening is also seen in leads I,aVL; and in leads V4,V5,V6 (<i>with a hint of ST depression in leads V5,V6</i>). Finally — the T waves in leads V4,V5,V6 are "fatter"-at-their-peak than they should be <b>(</b><i>beyond what might be expected from superposition of P waves on these T waves</i><b>)</b>. <b><u><i>KEY</i> Point:</u></b> Although the above ST-T wave changes are admittedly subtle — the fact that they are undeniably present in so many leads (<i>and most marked in lead V3</i>) <u>is</u> real!</li><li><br /></li><li><b><u>PEARL <span style="color: red;">#</span>3:</u></b> 2nd- and 3rd-degree AV blocks are a common complication of inferior <i>and/or</i> posterior OMI. As a result — the finding of ST segment flattening in multiple leads, but being <i>most marked</i> in <b>lead V3</b> — in a patient with bradycardia and some significant form of AV block — suggests a strong possibility of <b>recent <i><u>posterior</u></i> OMI (</b><i>See</i><b> <a href="https://ecg-interpretation.blogspot.com/2022/12/ecg-blog-351-posterior-leads.html" target="_blank">ECG Blog #351</a>)</b>.</li><li><br /></li><li><b><u>PEARL <span style="color: red;">#</span>4:</u></b> The fact that today's elderly patient was asymptomatic does <u style="font-style: italic;">not</u> rule out the possibility of having had an acute (<i>or recent</i>) MI. As discussed in <b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-228-44-what-is-main-problem.html" target="_blank">ECG Blog #228</a></b> — the incidence of <b><i>"<u>Silent</u>"</i></b> <b>MI</b> may be as high as between 20-40% of all MIs, being especially common in older individuals.</li></ul></div><div><span><br /></span></div><div><span><b><u><span style="font-style: italic;">M</span><i>Y <span>I</span>mpression</i> of <i>Today's</i> CASE:</u></b> Despite no symptoms — I strongly suspect from the initial ECG, that this older woman had a <b><i>recent</i></b> <b>LCx (</b><i><u>L</u>eft <u>C</u>ircumfle<u>x</u></i><b>) occlusion</b> with <b><i><u>posterior</u></i></b> <b>MI</b> — that resulted in bradycardia with 2nd- or 3rd-degree AV block. Given the lack of symptoms — this was a <b><i>“<u>silent</u>"</i></b> <b>MI</b>. The patient may need a pacemaker.</span></div><div><ul><li><b><u>CASE <span style="color: red;">F</span>ollow-<span style="color: red;">U</span>p:</u></b> Providers in today's case recognized the above abnormalities — and promptly referred the patient to a PCI center for cardiac catheterization and potential pacemaker insertion.</li></ul></div><div><span><br /></span></div><div><span><br /></span></div></div><div style="font-family: arial; text-align: justify;"><span style="color: #2e2d33;">==========================</span></div><div style="font-family: arial; text-align: justify;"><span><div style="caret-color: rgb(0, 0, 0);"><b><u><i><span style="color: red;">L</span>ooking <span style="color: red;">C</span>loser</i> at <i>Today's</i> <span style="color: red;">R</span>hythm:</u></b></div><div style="caret-color: rgb(0, 0, 0); color: black;"><span style="color: #2e2d33;">The rhythm in </span><span style="color: #2e2d33; text-decoration: underline;">Figure-1</span><span style="color: #2e2d33;"> has a number of complexities. As a result — I needed additional time before deciding on the precise rhythm diagnosis. </span><i style="color: #2e2d33;">I walk through my thought process below</i><span style="color: #2e2d33;">. But the point to emphasize — is that<b><i> it should only take </i></b></span><span style="color: #2e2d33; text-decoration: underline;"><b><i>seconds</i></b></span><span style="color: #2e2d33;"> to recognize that there is bradycardia from significant AV block.</span></div></span></div><div style="font-family: arial; text-align: justify;"><span style="color: #2e2d33;">======================</span></div><div style="font-family: arial; text-align: justify;"><b style="color: #2e2d33; text-decoration: underline;"><i><br /></i></b></div><div style="font-family: arial; text-align: justify;"><span style="color: #2e2d33;"><span style="caret-color: rgb(46, 45, 51);"><b><u><i>My </i>Approach to Rhythm Determination:</u></b></span></span></div><div style="font-family: arial; text-align: justify;"><ul><li><span style="text-decoration: underline;"><b><span style="color: #2e2d33;">PEARL </span><span style="color: red;">#</span><span style="color: #2e2d33;">5:</span></b></span><span style="color: #2e2d33;"> The simple step of </span><b style="color: #2e2d33;"><i><u>labeling</u></i> P waves</b><span style="color: #2e2d33;"> is tremendously helpful in facilitating rhythm diagnosis. I have done this with <i>RED arrows</i> in </span><span style="color: #2e2d33; text-decoration: underline;"><b>Figure-2</b></span><span style="color: #2e2d33;">.</span></li><li><span style="color: #2e2d33;">Prior to labeling the P waves — <i>Did YOU Notice</i> how much variation there is in P wave morphology?</span></li><li><span style="color: #2e2d33;"><br /></span></li><li><b><i>Is the atrial rhythm in <span style="text-decoration: underline;">Figure-2</span> regular?</i></b> If not — <i>How </i>does this realization <i>complicate</i> today's rhythm diagnosis?</li></ul></div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhE-OmwSJHCf6zfRqcnOSDqI1RL0icScqIPUICvemGY-4xNrhnNp5VhVhElnqp2KjvJzXPT0HLbB6nt47h_la4Yc4Sc_Z1ZnGPzOs_nVK5mg8PqnwEq1WcsI44z_Jxjh24_bCuDL8j_IRhlgyJ57VItZPKzNr-wInSzXZE_fikF0nFrs-bHcqoB_lAHf6k/s3788/Figure-2%20%20ECG-1%20P%20Waves%20(1-13.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="2058" data-original-width="3788" height="217" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhE-OmwSJHCf6zfRqcnOSDqI1RL0icScqIPUICvemGY-4xNrhnNp5VhVhElnqp2KjvJzXPT0HLbB6nt47h_la4Yc4Sc_Z1ZnGPzOs_nVK5mg8PqnwEq1WcsI44z_Jxjh24_bCuDL8j_IRhlgyJ57VItZPKzNr-wInSzXZE_fikF0nFrs-bHcqoB_lAHf6k/w400-h217/Figure-2%20%20ECG-1%20P%20Waves%20(1-13.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-2:</u></b><span style="text-align: justify;"> I've labeled P waves with <i>RED </i>arrows.</span></span></td></tr></tbody></table><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><b><u>PEARL <span style="color: red;">#</span>6:</u></b> In Figure-2 — <i>Isn't there a <u>lot</u> of variation in P wave morphology</i>? This raises the question as to whether each of the <i>RED</i> arrow P waves is a sinus P wave? — <u>OR</u> — Is the underlying rhythm sinus with atrial bigeminy <b>(</b>ie, <i>every-other-P-wave being a PAC?</i><b>)</b>.</div><div style="font-family: arial; text-align: justify;"><ul><li><u>NOTE:</u><b> A certain amount of variation in P wave morphology is common in sinus rhythms</b> — be this from patient (<i>or electrode lead</i>) movement — from artifact — <u>or</u> — <b><i>from more complex factors</i></b> that may include variation in the exit site of atrial depolarization from the SA node — variation in the impulse path through the atria <i>and/or</i> in the degree of intra-atrial conduction block <b>(</b><i>Qin et al: </i><b><a href="https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.118.038396" target="_blank">Circulation 139:1225-1227, 2019</a></b> — <i>Pezzuto et al: </i><b><a href="https://academic.oup.com/europace/article/20/suppl_3/iii26/5202144" target="_blank">EP Europace 20, 2018</a> </b>—<b> </b><i>Platonov</i>: <b><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6932587/" target="_blank">Ann Noninvasive Electrocardiol 17(3):161-169, 2012</a></b><b>)</b>.</li><li>While acknowledging that a certain amount of variation in P wave morphology <u>is</u> often seen with sinus rhythms — <b>there usually is <i><u>not</u></i> as much variation as is seen in <u>Figure-2</u></b> <b>(</b>ie, <i>from the fairly tall and pointed P wave before beat #5 — compared to the tiny, flat P wave in front of beat #6</i><b>)</b>.</li><li><br /></li><li><u style="font-weight: bold;">BOTTOM Line:</u> The above said — <b>I strongly suspect</b> that <u style="font-style: italic;">despite</u> marked variability in P wave morphology in today's tarcing — that <b><i><u>all</u></i> of the <i>RED</i> arrow P waves</b> in <u>Figure-2</u> <b>are</b> <b><i>sinus </i>P waves!</b> I say this because of the PR and R-R intervals that I will measure momentarily in <u style="font-weight: bold;">Figure-3</u> <b>(</b>ie,<i> The PR interval continually varies — whereas it should be constant if the rhythm was sinus with atrial bigeminy</i><b>)</b>.</li></ul></div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><b><u>PEARL <span style="color: red;">#</span>7:</u></b> As is evident for many of the examples of AV block that have appeared in this ECG Blog — it is common to see a <b><i>"<u>ventriculophasic</u>" </i>sinus arrhythmia</b> in association with 2nd or 3rd degree AV block. Much of the time <b>(</b><i>as is the case in </i><u>Figure-2</u><b>)</b> — the <i>shorter</i> P-P interval is the one that “sandwiches” a QRS complex <b>(</b><i>the theory being that perfusion improves following ventricular contraction — with resultant shortening by a slight amount of the P-P interval that contains a QRS</i><b>)</b>.</div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;">=============================</div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><b><u><i>Measuring</i> Intervals:</u></b></div><div style="font-family: arial; text-align: justify;">I needed <b><i><u>calipers</u></i></b> to "solve" today's rhythm.</div><div style="font-family: arial; text-align: justify;"><ul><li><b><u>PEARL <span style="color: red;">#</span>8:</u></b> My favorite PEARL for distinguishing 2nd-degree from 3rd-degree AV block is knowing that in the presence of an underlying sinus rhythm —<b> a QRS complex that occurs </b><i style="font-weight: bold;">earlier-than-expected</i><b> is </b><i style="font-weight: bold;">probably</i> <u style="font-weight: bold;">conducted</u> <b>(</b><i>therefore the rhythm is unlikely to be complete AV block!</i><b>)</b>.</li><li>In contrast — <b>the <i><u>escape</u></i> rhythm with <i>complete</i> AV block will usually be <u>regular</u> (</b><i>or at least, almost regular</i><b>)</b>. This is why careful measurement of <i>both</i> PR and R-R intervals is essential for solving today's rhythm <b>(</b><i>See</i> <u style="font-weight: bold;">Figure-3</u><span style="font-weight: bold;">)</span>.</li></ul></div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8uithRnYRFaloZrM2cmvb8ySTPkGfXfxerI4ltopiDZmkV9ENGjnWTPpGJylzg_oySlezwVx1xBQP3lS_KnVYrdTNfA5rGfTEEIo0GvLYL-xx3TBUlZPIKw0CPRHzWzjt_HNytkyHbH8jRgKNKm9jkYTBKDgKwDrmka5sjrXz2jw3pvUOGsTbeGR8wUk/s3742/Figure-3%20%20Intervals%20(1-13.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="546" data-original-width="3742" height="59" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8uithRnYRFaloZrM2cmvb8ySTPkGfXfxerI4ltopiDZmkV9ENGjnWTPpGJylzg_oySlezwVx1xBQP3lS_KnVYrdTNfA5rGfTEEIo0GvLYL-xx3TBUlZPIKw0CPRHzWzjt_HNytkyHbH8jRgKNKm9jkYTBKDgKwDrmka5sjrXz2jw3pvUOGsTbeGR8wUk/w400-h59/Figure-3%20%20Intervals%20(1-13.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-3:</u></b><span style="text-align: justify;"> I have carefully measured PR and R-R intervals.</span></span></td></tr></tbody></table><br /><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><div><b><u><i>Applying</i> the Measurements in Figure-3:</u></b></div><ul><li>Note in Figure-3 that <b>the ventricular rhythm is <i>completely</i> <u>regular</u>! </b><b>(</b>ie, <i>all R-R intervals = 1680 msec</i>.<b>)</b>.</li><li>Note also that despite "looking" similar — <b>there is <i>slight-but-definite</i> variation in the PR interval from one beat to the next. </b>This rules out the possibility of sinus rhythm with atrial bigeminy — because the PR interval varies from beat-to-beat <b>(</b><i>whereas it should be constant if the rhythm was sinus</i><b>)</b>.</li><li><i>As per</i> PEARL #8 — <i>None</i> of the 6 beats in <u>Figure-3</u> occur earlier-than-expected. This strongly suggests that <i>none</i> of the <i>RED</i> arrow P waves are being conducted — and that the rhythm probably is <b><u>complete</u> (</b> =<i> 3rd-degree</i><b>) AV block</b>.</li><li>As noted in PEARL #6 — despite marked variation in P wave morphology, I suspect that <b>all <i>RED</i> arrow P waves are sinus impulses</b>. In view of the likelihood of complete AV block — it would seem highly unlikely for the same pattern of P wave rhythmicity <b>(</b>ie, <i>shorter-than-longer P-P intervals</i><b>)</b> — to be seen if the multiple variations in P wave shape were all originating from different atrial foci.</li><li><br /></li><li><b><u><i>Advanced </i>Point</u> (</b><i>Beyond-the-Core</i><b>):</b> Technically, the rhythm strip in today's tracing is<i> too short </i>to prove that the rhythm is complete AV block. This is because we do <u style="font-style: italic;">not</u> see P waves occurring at <u style="font-style: italic;">all</u> points within the R-R interval (ie, <i>There are <u>no</u> P waves occurring near the middle of the R-R interval</i>). That said, this does <i><u>not</u></i> matter clinically — because <i><u>regardless</u></i> of the degree of AV block, prompt referral to a PCI center is indicated given likely recent posterior OMI with marked bradycardia and <i>at least</i> 2nd-degree AV block.</li></ul></div><div style="font-family: arial; text-align: justify;"><b><u><span style="color: red;"><br /></span></u></b></div><div style="font-family: arial; text-align: justify;"><b><u><span style="color: red;">L</span>ADDERGRAM:</u></b></div><div style="font-family: arial; text-align: justify;">I conclude my comments with a laddergram for the rhythm in today's case. At the least — <b>there is <u style="font-style: italic;">no</u> conduction of any of the <i>RED</i> arrow P waves</b> because: <b>i<span style="color: red;">)</span></b> The ventricular rhythm is regular <b>(</b><i>here, at a rate just under 40/minute</i><b>)</b>; — <u>and</u>, <b>ii<span style="color: red;">)</span></b><span style="color: red;"> </span>The PR interval continually varies.</div><div style="font-family: arial; text-align: justify;"><ul><li>The QRS complex is narrow. This defines the escape rhythm focus as either arising in the AV node <u>or</u> from the Bundle of His <b>(</b><i>with the rate of less than 40/minute being a bit slow for an AV nodal escape rhythm</i><b>)</b>.</li></ul></div><div style="font-family: arial; text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjIac1QvgR3XhyphenhypheneXi-pD7H_cj8Ra9WbLXpkdkEEqs-KUGp-JDGvpTnnnKqb-eKBxwrbBb3xzXTdiz_1mLUsjWoUQxUz2gKzixcfbBOmQB5-FFNKBjjMC6SuqRaLr-zq4EMGgHH_x_D5e7_fLp4MLW6onQ2Jbff6A7XdhQujT0L5RebXuu8eAVwQw7dbM2g/s3694/Figure-4%20%20ECG-1%20Laddergram%20(1-13.1-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1574" data-original-width="3694" height="170" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjIac1QvgR3XhyphenhypheneXi-pD7H_cj8Ra9WbLXpkdkEEqs-KUGp-JDGvpTnnnKqb-eKBxwrbBb3xzXTdiz_1mLUsjWoUQxUz2gKzixcfbBOmQB5-FFNKBjjMC6SuqRaLr-zq4EMGgHH_x_D5e7_fLp4MLW6onQ2Jbff6A7XdhQujT0L5RebXuu8eAVwQw7dbM2g/w400-h170/Figure-4%20%20ECG-1%20Laddergram%20(1-13.1-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-4:</u></b><span style="text-align: justify;"> My laddergram for today's case.</span></span></td></tr></tbody></table><br /><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><b><u><i><span style="color: red;">T</span>ake-<span style="color: red;">H</span>ome</i> POINTS:</u></b></div><div style="font-family: arial; text-align: justify;"><ul><li>Today's case conveys a number of <u style="font-style: italic;">advanced</u> concepts. My goal is to <i>challenge</i> experienced interpreters through discussion of these advanced concepts. As always — <i>Your comments are welcome!</i> </li><li>Recognition of the subtle ECG findings I point out regarding the 12-lead tracing in today's case are important details to be aware of! <u style="font-weight: bold;">To Emphasize:</u> As soon as I recognize significant bradycardia with <i>some</i> form of AV block — <i><b>I <u>actively</u> look for recent evidence of acute OMI</b>. </i>By appreciating the need to look for subtle signs of recent inferior <i>and/or</i> posterior OMI — <i>you greatly increase the chance that you will find it!</i></li><li><i><br /></i></li><li>The above said — <b>Today's case conveys important information for <u style="font-style: italic;">any</u> level interpreter.</b> Less experienced providers will hopefully appreciate how application of the Ps,Qs,3R approach allows you <u style="font-style: italic;">within</u> seconds to recognize the essentials of today's rhythm enough to tell us to cancel non-emergent surgery, and to promptly refer this patient to a catheterization-capable center.</li></ul></div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><div><br /></div></div><div style="text-align: justify;"><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;">==============================<o:p></o:p></span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Mohamed Salah (<i>from Muscat, Oman</i>) for the case and this tracing.<o:p></o:p></span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;">==================================<o:p></o:p></span></span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;"> </span></span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span><b style="font-family: arial;"><i><u><span style="color: red;">R</span></u></i></b><b style="font-family: arial;"><i><u>elated</u></i></b><b style="font-family: arial;"><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></p><div style="text-align: left;"><div style="text-align: justify;"><ul style="font-family: arial;"><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span>S</span>ystematic</i></b> <b><span>A</span>pproach</b> to 12-lead ECG Interpretation.</li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — Review of the <b><span><u>P</u></span>s, <span><u>Q</u></span>s, 3<span><u>R</u></span> Approach</b> for systematic rhythm interpretation.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> <b><i>draw</i> </b></span><span style="font-family: arial; font-size: medium;"><b>L</b></span><b>addergrams (</b><i>with LINKS to more than 100 laddergram cases — many with step-by-step sequential illustration</i><b>)</b><span style="font-family: arial;">.</span></li></ul><div><ul style="font-family: -webkit-standard; text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2022/12/ecg-blog-351-posterior-leads.html" target="_blank">ECG Blog #351</a></b> — reviews the diagnosis of <b>acute <i><u>posterior</u></i> OMI</b>. To see this illustrative case presented as an <b><i>ECG</i> </b></span><b style="font-family: arial;"><u>Video</u></b><span style="font-family: arial;"> — Please check out </span><b style="font-family: arial;"><a href="https://ecg-interpretation.blogspot.com/2023/12/ecg-blog-406-to-do-additional-leads.html" target="_blank">ECG Blog #406</a></b><span style="font-family: arial;"> </span><b style="font-family: arial;">(</b><i style="font-family: arial;">For a LINKED Contents to this ECG Video — Click on MORE in the Description under the video on YouTube</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2023/11/ecg-blog-405-is-av-block-complete-vs-av.html" target="_blank">ECG Blog #405</a></b> — <b><i>ECG</i></b> <b><u>Video</u></b> presentation that reviews the distinction between <b>AV Dissociation</b> <i><u>vs</u></i> <b>Complete (</b><i>3rd-degree</i><b>) AV Block</b> </span><b style="font-family: arial;">(</b><i style="font-family: arial;">For a LINKED Contents to this ECG Video — Click on MORE in the Description under the video on YouTube</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2019/05/ecg-blog-164-pacs-blocked-pacs.html" target="_blank">ECG Blog #164</a></b> — Which reviews <i>step-by-step</i> the diagnosis of a <b>Mobitz I 2nd-degree AV block (</b><i>with sequential laddergram illustration</i><b>)</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b style="font-family: arial;"><a href="https://ecg-interpretation.blogspot.com/2021/10/ecg-blog-258-mp-70-how-to-date-mi.html" target="_blank">ECG Blog #258</a></b><span style="font-family: arial;"> — How to </span><b style="font-family: arial;"><i>"<span>D</span>ate"</i></b><span style="font-family: arial;"> an </span><b style="font-family: arial;"><span>I</span>nfarction</b><span style="font-family: arial;"> based on the </span><i style="font-family: arial;">initial</i><span style="font-family: arial;"> ECG.</span></li><li><b style="font-family: arial; text-align: justify;"><a href="https://ecg-interpretation.blogspot.com/2022/03/ecg-blog-294-one-hour-later.html" target="_blank">ECG Blog #294</a></b><span style="font-family: arial; text-align: justify;"> </span><span style="font-family: arial; text-align: justify;">— Reviews how to tell</span><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;"><i>IF the "culprit" artery has reperfused</i></b><span style="font-family: arial; text-align: justify;">.</span></li><li><b style="font-family: arial; text-align: justify;"><a href="https://ecg-interpretation.blogspot.com/2021/06/ecg-blog-230-46-are-there-serial-ecg.html" target="_blank">ECG Blog #230</a></b><span style="font-family: arial; text-align: justify;"> — Reviews how to </span><b style="font-family: arial; text-align: justify;"><i>compare</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">Serial</b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">ECGs</b><span style="font-family: arial; text-align: justify;">.</span></li><li><b style="font-family: arial; text-align: justify;"><a href="https://ecg-interpretation.blogspot.com/2015/07/ecg-blog-115-early-repolarization.html" target="_blank">ECG Blog #115</a></b><span style="font-family: arial; text-align: justify;"> — Shows how dramatic ST-T changes can occur in as short as an 8-minute period.</span></li><li><b style="font-family: arial; text-align: justify;"><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-268-76-mobitz-i-vs-complete-av.html" target="_blank">ECG Blog #268</a></b><span style="font-family: arial; text-align: justify;"> — Shows an example of </span><b style="font-family: arial; text-align: justify;"><i>reperfusion</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">T waves</b><span style="font-family: arial; text-align: justify;">.</span></li></ul><div style="text-align: justify;"><ul><li><span style="font-family: arial;">Diagnosis of an <b>OMI</b> from the <i>initial</i> ECG — <u style="font-style: italic;">Serial</u> tracings with <b><i>spontaneous</i></b> <b>reperfusion</b> — then reocclusion! —</span><span style="font-family: arial;"> See </span><i style="font-family: arial;">My Comment</i><span style="font-family: arial;"> at the bottom of the page in the </span><b style="font-family: arial;"><a href="http://hqmeded-ecg.blogspot.com/2020/10/dynamic-st-elevation.html" target="_blank">October 14, 2020</a></b><span style="font-family: arial;"> </span><b style="font-family: arial;">post</b><span style="font-family: arial;"> on Dr. Smith's ECG Blog.</span></li><li><span style="font-family: arial;">Acute OMI that </span><i style="font-family: arial;">wasn’t</i><span style="font-family: arial;"> accepted by the Attending — See </span><i style="font-family: arial;">My Comment</i><span style="font-family: arial;"> at the bottom of the page in the </span><b style="font-family: arial;"><a href="http://hqmeded-ecg.blogspot.com/2020/11/the-resident-made-diagnosis-immediately.html" target="_blank">November 21, 2020</a> post</b><span style="font-family: arial;"> on Dr. Smith’s ECG Blog.</span></li><li><span style="font-family: arial;">Another </span><i style="font-family: arial;"><u>overlooked</u></i><span style="font-family: arial;"> OMI</span><span style="font-family: arial;"> </span><b style="font-family: arial;">(</b><i style="font-family: arial;">Cardiologist limited by STEMI Definition — OMI evident by <b>Mirror Test</b></i><b style="font-family: arial;">)</b><span style="font-family: arial;"> </span><span style="font-family: arial;">— See </span><i style="font-family: arial;">My Comment</i><span style="font-family: arial;"> at the bottom of the page in the </span><b style="font-family: arial;"><a href="https://hqmeded-ecg.blogspot.com/2020/09/interventionalist-at-receiving-hospital.html" target="_blank">September 21, 2020</a> post</b><span style="font-family: arial;"> on Dr. Smith’s ECG Blog.</span></li><li><span style="font-family: arial;">Recognizing </span><b style="font-family: arial;"><i>hyperacute</i></b><span style="font-family: arial;"> </span><b style="font-family: arial;">T waves</b><span style="font-family: arial;"> — patterns of leads — an </span><b style="font-family: arial;">OMI (</b><i style="font-family: arial;">though <u>not</u> a STEMI</i><b style="font-family: arial;">)</b><span style="font-family: arial;"> — See </span><i style="font-family: arial;">My Comment</i><span style="font-family: arial;"> at the bottom of the page in the </span><b style="font-family: arial;"><a href="http://hqmeded-ecg.blogspot.com/2020/11/this-skill-can-be-taught-and-learned.html" target="_blank">November 8, 2020</a> post</b><span style="font-family: arial;"> on Dr. Smith's ECG Blog.</span></li></ul></div></div><div style="font-family: arial;"><br /></div></div></div><p class="MsoNormal" style="font-family: arial; text-align: left;"><span style="font-family: arial;"></span></p><div style="font-family: arial; text-align: left;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhcUanPtyekRxG_NN3M6G7ixBWDiaFwP9HSTmmxsiAGLgKFyGGIePOLicsrDGS_HrTpJuFvbsUgWw_X6ZXKehXoAeVAyPHHXStk2lmG9uzuY33nE1KZQCLDvOH1VKIkbTzKmck2XR3I6_wmONnxXQmAen5uT-Ez0rJCH23wswN1g0uETqzQQugv30VE=s613" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/a/AVvXsEhcUanPtyekRxG_NN3M6G7ixBWDiaFwP9HSTmmxsiAGLgKFyGGIePOLicsrDGS_HrTpJuFvbsUgWw_X6ZXKehXoAeVAyPHHXStk2lmG9uzuY33nE1KZQCLDvOH1VKIkbTzKmck2XR3I6_wmONnxXQmAen5uT-Ez0rJCH23wswN1g0uETqzQQugv30VE=w400-h16" width="400" /></a></span></div></div><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; margin: 0in; white-space: normal;"><span style="font-family: arial;"><b><u><span style="color: red;">A</span></u></b><b><u>DDENDUM <span style="color: red;">(</span></u></b><i><u>1/20/2024</u></i><b><u><span style="color: red;">)</span></u></b><b><u>:</u></b> </span></p><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; margin: 0in; white-space: normal;"></p><ul><li><span style="font-family: arial;">Included below is a series of additional material relevant to today's case. </span></li></ul><p></p><p style="text-align: left;"></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial;"> </span></p><p class="MsoNormal" style="margin: 0in;"><b><span style="font-family: arial;"><i>Free</i> <u><span style="color: red;">P</span>DF</u> <u><span style="color: red;">D</span>ownloads</u> from <i>relevant</i> Sections in my ECG-2014-ePub:</span></b></p><p class="MsoNormal" style="margin: 0in;"></p><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; margin: 0in;"><span style="font-family: arial;"></span></p><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://www.dropbox.com/s/bfkhjrzqnnv1s2c/10.16-28-%20Coronary%20Circ-Culprit%20%282-10.23-2021%29-Lock-USE.pdf?dl=0" target="_blank">PDF File:</a></b> Overview on the Cardiac Circulation and the “Culprit” Artery in Acute MI —</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://www.dropbox.com/s/c9lrdwkz80gz9ol/10.33-%20ECG-2014-e-PUB-Post%20MI-Mirror%20Test-%2810-16.1-2014%29-LOCK.pdf?dl=0" target="_blank">PDF File:</a></b> Posterior MI and the “Mirror Test” —</span></li></ul><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; font-family: arial; margin: 0in; white-space: normal;"><span style="font-family: arial;"> </span></p><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; font-family: arial; margin: 0in; white-space: normal;"><span style="font-family: arial;"><br /></span></p><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; font-family: arial; margin: 0in; white-space: normal;"><span style="font-family: arial;"></span></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: -webkit-standard; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkK-CI0tNg9si9WlGL0hEgd9TMBDJSMhJic0qBjw5ZB6SIYsl6pB_0RLF6rPCw7cWABoT_ferdPbfp8CAgbhCMp0R3ODWxbvAjzPGad8wqoAN3lIZ1XtdH3GDKxnsX4AWrfwCXWxvSH8g/s2048/Figure-3+ECG+Findings+to+Look+For+%25282-10.1-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial;"><img border="0" data-original-height="1651" data-original-width="2048" height="323" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkK-CI0tNg9si9WlGL0hEgd9TMBDJSMhJic0qBjw5ZB6SIYsl6pB_0RLF6rPCw7cWABoT_ferdPbfp8CAgbhCMp0R3ODWxbvAjzPGad8wqoAN3lIZ1XtdH3GDKxnsX4AWrfwCXWxvSH8g/w400-h323/Figure-3+ECG+Findings+to+Look+For+%25282-10.1-2021%2529-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #333333;">Figure-5:</span></u></b><span style="color: #333333; text-align: justify;"> ECG findings to look for <b>when your patient</b> with <i>new-onset</i> cardiac symptoms <b>does <i><u>not</u></i> manifest <i>STEMI-criteria</i> ST elevation</b> on ECG. For more on this subject — <i>SEE the</i> <b><a href="http://hqmeded-ecg.blogspot.com/2020/08/omi-manifesto-lecture-in-20-minutes-via.html" target="_blank">September 3, 2020</a> post</b> in Dr. Smith’s ECG Blog with 20-minute video talk by Dr. Meyers on <b><i>The </i></b></span><b style="text-align: justify;"><i><span style="color: red;">O</span></i></b><b style="text-align: justify;"><i><span style="color: #333333;">MI </span></i></b><b style="text-align: justify;"><i><span style="color: red;">M</span></i></b><b style="text-align: justify;"><i><span style="color: #333333;">anifesto</span></i></b><span style="color: #333333; text-align: justify;">. For my clarifying Figure illustrating <b>T-QRS-D</b> (<i>2nd bullet</i>) — See <i><u>My</u> <u>Comment</u></i> at the <u>bottom</u> of the page in Dr. Smith’s <b><a href="http://hqmeded-ecg.blogspot.com/2019/11/a-50-something-with-left-shoulder-pain.html" target="_blank">November 14, 2019</a> post</b>.</span></span></td></tr></tbody></table><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; font-family: arial; margin: 0in; white-space: normal;"><span style="font-family: arial;"><br /></span></p><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; font-family: arial; margin: 0in; white-space: normal;"><span style="font-family: arial;"><br /></span></p><p class="MsoNormal" style="-webkit-text-stroke-width: 0px; font-family: arial; margin: 0in; white-space: normal;"><span style="font-family: arial;"> </span></p><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"><span style="font-family: arial;"><span style="caret-color: rgb(0, 0, 0); color: black; font-family: arial; text-align: left;"><span style="caret-color: rgb(51, 51, 51); color: #333333;"></span></span></span></span></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: arial; margin-left: auto; margin-right: auto; text-align: justify;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgIM3RW_Dt3m1Vi8dkkCYLcLkPKMJgVr6PDb9lI96TvHrxdVwEUlYPNLyX-xQwx_Gm32y4VYhIjIs0zyHuizc8KGLFV5hVosA5K9YtwJyUTB_Na1ONzrFHWNa17T-BRDGBPDOaB4cZd3-U/s2048/Figure-3+Isolated+Post.+MI+%25288-22.1-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial;"><img border="0" data-original-height="1511" data-original-width="2048" height="295" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgIM3RW_Dt3m1Vi8dkkCYLcLkPKMJgVr6PDb9lI96TvHrxdVwEUlYPNLyX-xQwx_Gm32y4VYhIjIs0zyHuizc8KGLFV5hVosA5K9YtwJyUTB_Na1ONzrFHWNa17T-BRDGBPDOaB4cZd3-U/w400-h295/Figure-3+Isolated+Post.+MI+%25288-22.1-2021%2529-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u><span style="color: #333333;"><span style="font-family: arial;">Figure-6:</span></span></u></b><span style="color: #333333; text-align: justify;"><span style="font-family: arial;"> KEY points in the recognition of <b><i><u>isolated</u></i> posterior MI (</b><i>This figure is taken from</i> <b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-193-ecg-mp-10-acute-omi.html" target="_blank">ECG Blog #193</a></b> <i>— in which I review the "Basics" for predicting the "culprit" artery</i><b>)</b>. </span></span></span></td></tr></tbody></table><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"><br /></span></p><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"><br /></span></p><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"><br /></span></p><div class="separator" style="clear: both; font-family: arial; text-align: center;"><span style="font-family: arial;"><a href="https://dl.dropbox.com/s/8wvnn0e4sgno5zl/z-ECG%20Audio%20Pearl-60%20Mirror%20Test%20%288-22.1-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1409" data-original-width="2048" height="275" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjQlLy2uKNov2o9GQXo_VAMlTFVmW_4ONBgEUhIr4XUZ-5zAfpmRs0xxHc_6yTXzQGrRdX3hoADofVO9Uw9lG6_PSF63ol1mIhSZos1JwakIUm_FspP0nHSso5OzE2W-Q5Uv7pQ-kBhw4/w400-h275/ECG-MP-60+-+Mirror+Test+%25288-22.21-2021%2529-USE.png" width="400" /></span> —</a><span style="text-align: justify;"> </span></span></div><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="font-family: arial;"><b><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>60 (</b><i>8:30 minutes</i> <b><i><u>Audio</u></i>)</b> — Reviews use of the <b><i>"</i></b><b><i><span style="color: red;">M</span>irror <span style="color: red;">T</span>est"</i></b> to facilitate recognition of: <b>i</b><b><span style="color: red;">)</span> Acute <i>Posterior</i> MI; ii<span style="color: red;">)</span> Acute <i>High-Lateral</i></b> <u>or</u> <b><i>Inferior</i></b> <b>MI (</b>ie, <i>the <b>"<u>magical</u>" reciprocal relationship</b> between leads III and aVL</i><b>)</b>; <u>and</u>, <b>iii</b><b><span style="color: red;">)</span> <i>Anterior</i> ST elevation</b> due to <b>LVH (</b><i>that is <u>not</u> indicative of anterior MI</i><b>)</b>.</span></p><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"><br /></span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial;"> </span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial;"><br /></span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; font-family: -webkit-standard; text-align: center;"><span style="font-family: arial;"><a href="https://dl.dropboxusercontent.com/s/tj2n20hmg0fuhj2/z-ECG%20Audio%20Pearl-10-OMI-Culprit%20%282-12.5-2021%29-USE-Faster.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1252" data-original-width="2048" height="245" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqqr9rDjZmLTqgW7bhmsiYB9L0uhZ8WTpJh0mdAUANMCzcgIa40oZ2eDCeW5NgPxfHFqhS9hMjZv3Ud8_fo7hF2pjfdJxm4uSfiHhCdjUaywDThjhh48gWNZMUMnyMLqCfb8HkY9SIY30/w400-h245/MP-10+%2528193%2529+OMI-+Culprit+Artery-USE.png" width="400" /></span> —</a></span></div><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"></span></p><p style="font-family: -webkit-standard; text-align: left;"></p><p style="font-family: arial; text-align: left;"></p><div class="separator" style="-webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; clear: both; font-family: -webkit-standard; orphans: auto; text-align: center; white-space: normal; widows: auto;"><span style="text-align: left;"><div style="display: inline; text-align: justify;"><span style="font-family: arial;"><b><span style="color: red;">E</span>CG <span style="color: red;">M</span>edia <span style="color: red;">P</span>EARL <span style="color: red;">#</span>10 (</b>10 minutes <u>Audio</u><b>)</b> — reviews the concept of why the term <b>“OMI” (</b> = <i><u>O</u>cclusion-based <u>MI</u></i><b>) </b>should <i><u>replace</u></i> the more familiar term STEMI — <u>and</u> — reviews the basics on how to <b><i>predict</i></b> the <b><i>"culprit"</i></b> <b>artery</b>.</span></div></span></div><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"><br /></span></p><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"><br /></span></p><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"><br /></span></p><div class="separator" style="clear: both; font-family: -webkit-standard; text-align: center;"><span style="font-family: arial;"><a href="https://dl.dropboxusercontent.com/s/4ublcje6en3xvhv/z-ECG%20Audio%20Pearl-11%20Reperfusion%20%282-12.5-2021%29-USE-Faster.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1432" data-original-width="2048" height="280" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwAubBMD5ekmWf3JU7rJL_rSjod3oxr_S-N358ThxTg8uS4T5qwXgSniTBctjJ7vQ45lo8uBjPxsJX6Z0ar7FsKlYV2CIFdC2MnQV8BM_emnMYa_fJdiArLOTAV1c8ICdRyyM-TW_cvA0/w400-h280/MP-11+%2528194%2529-Has+Culprit+Reperfused-USE.png" width="400" /></span> —</a></span></div><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"><span style="font-family: arial;"></span></span></p><div class="separator" style="clear: both; font-family: -webkit-standard; text-align: center;"><span style="text-align: left;"><div style="display: inline; text-align: justify;"><span style="font-family: arial;"><b><span style="color: red;">E</span><span style="font-style: italic;"><span style="font-style: normal;">CG</span> <span style="color: red;">M</span>edia</span><i> </i><span style="color: red;">P</span>EARL <span style="color: red;">#</span>11 (</b><span style="font-style: italic;">6 minutes <u>Audio</u></span><b>)</b><i> — </i>Reviews how to tell IF the <b>“culprit”</b> <b>(</b><i>ie,</i><b style="font-style: italic;"> </b><span style="font-style: italic;">acutely occluded</span><b>) artery</b> has<i> reperfused, </i>using clinical and ECG criteria<i>.</i></span></div></span></div><div style="font-family: arial; text-align: left;"><span><div style="display: inline; text-align: justify;"><span style="font-family: arial;"><i><br /></i></span></div></span></div><p class="MsoNormal" style="font-family: arial; margin: 0in;"><br /></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;">==================================</span></span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><div style="font-family: -webkit-standard; text-align: left;"><div style="text-align: justify;"><b style="font-family: arial;"><u><i><span style="color: red;">A</span>dditional</i> <span style="color: red;">M</span>aterial on <i><span style="color: red;">T</span>oday's</i> <span style="color: red;">C</span>ASE:</u></b></div><div style="text-align: justify;"><b style="font-family: arial;"><u><br /></u></b></div></div><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: -webkit-standard; margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td><div class="separator" style="clear: both;"><a href="https://dl.dropboxusercontent.com/s/p5o4fsrvt6mzqv3/z-ECG%20Audio%20Pearl-4%20%282-12.1-2021%29-USE-Faster.m4a?dl=0" target="_blank"><span style="font-family: arial; font-size: medium;">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1470" data-original-width="2048" height="288" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUAcJgawC2j9KDwKlACfTSKiiFHIo_a9sS0f1ZnbphiPfeBWj2mSS913KvLr_WX6iCOOpF-G8Bprw20u8pN73MMgyBaMr4Q21EXsDMgYLbRZSWW-bKbUSMQjiEFEj72JNPtxlA1iLfHe8/w400-h288/MP-4+%2528186%2529-Suspect+Mobitz+I-USE.png" width="400" /></span> —</span></a></div><span style="font-family: arial; font-size: medium;"><br /></span></td></tr><tr><td class="tr-caption"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span><span>4</span></u></b><b style="text-align: justify;"> (</b><i><span style="text-align: justify;">4:3</span><span style="text-align: justify;">0</span></i><i style="text-align: justify;"> minutes <b><u>Audio</u></b></i><b style="text-align: justify;">)<span style="color: red;">:</span></b><span style="text-align: justify;"> — takes a brief look at the <b>AV Blocks</b> — and focuses on <i>WHEN</i> to <i>suspect</i> <b>Mobitz I</b>.</span></span></td></tr></tbody></table><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><br /></p><div style="font-family: -webkit-standard; text-align: left;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwH4zab67Smbft7R9OPI1Qt_EIabvd1wkRjbtgdprf9x2DTzFyxpfip8X5v1FQ1JRipbXXDMjNsoFUG5Ly7O5PM-dQypN1q5O7es89cSBR7bLiSIyXgqgKiPOE4sddPqpzEmyZ97L5eak/s3070/MP-8+%2528191-Video%2529+AV+Diss+vs+Complete+AV+Block-USE+copy.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="314" data-original-width="3070" height="41" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwH4zab67Smbft7R9OPI1Qt_EIabvd1wkRjbtgdprf9x2DTzFyxpfip8X5v1FQ1JRipbXXDMjNsoFUG5Ly7O5PM-dQypN1q5O7es89cSBR7bLiSIyXgqgKiPOE4sddPqpzEmyZ97L5eak/w400-h41/MP-8+%2528191-Video%2529+AV+Diss+vs+Complete+AV+Block-USE+copy.png" width="400" /></a></div><b style="text-align: justify;"><br /></b></span></div><div style="font-family: -webkit-standard; text-align: left;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dysO6DANFGgwZPX5Dra5J7ztG2RMSKaouHcHjWJEEsiucmIemNKIuwQV_WaPYnWP9RaXN_NP5p71ZL9a2RJlg' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div></span></div><div style="font-family: -webkit-standard; text-align: left;"><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;">ECG Media Pearl <span style="color: red;">#</span>8 (</b><i style="text-align: justify;">8:20 minutes <b><u>Video</u></b></i><b style="text-align: justify;">)</b><span style="text-align: justify;"> — <b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-191-ecg-mp-8-is-av-block.html" target="_blank">ECG Blog #191</a></b> — Distinguishing between <b><span style="color: red;">A</span>V <span style="color: red;">D</span>issociation</b> <u>vs</u> <b>Complete AV Block (</b><i>2/6/2021</i><b>)</b>.</span></span></div><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><br /></b></span></div><div style="font-family: -webkit-standard; text-align: left;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><br /></b></span></div><div style="font-family: -webkit-standard; text-align: left;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><br /></b></span></div><div style="font-family: -webkit-standard; text-align: left;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWChGeXVP0DDrXM8tMWCDsC8lzeWBDX5T2oTgH0eNbHd-3kACbTcZt7FA8E8Q4cXmYXNr4kd0o3agQkVm2qppt2tqHgxvK3t-e1wWlOM66onmMH8RPofPZHAKJkp48slLOL4tTcTYDvTk/s2736/MP-9+%2528192-Video%2529+Causes+of+AV+Dissociatio-USE+copy.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="292" data-original-width="2736" height="43" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWChGeXVP0DDrXM8tMWCDsC8lzeWBDX5T2oTgH0eNbHd-3kACbTcZt7FA8E8Q4cXmYXNr4kd0o3agQkVm2qppt2tqHgxvK3t-e1wWlOM66onmMH8RPofPZHAKJkp48slLOL4tTcTYDvTk/w400-h43/MP-9+%2528192-Video%2529+Causes+of+AV+Dissociatio-USE+copy.png" width="400" /></a></div><b style="text-align: justify;"><br /></b></span></div><div style="font-family: -webkit-standard; text-align: left;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dyu08Ud1F6LXzBNmHis5llLMASy1b1ECbpf23ZXbnSdNmdfWSCn1F0uuBArqHuONR4UCzk7Qll0iCypymQeqg' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div></span></div><div style="font-family: -webkit-standard; text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;">ECG Media Pearl <span style="color: red;">#</span>9 (</b><i style="text-align: justify;">5:40 minutes <b><u>Video</u></b></i><b style="text-align: justify;">)</b><span style="text-align: justify;"> — <b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" target="_blank">ECG Blog #192</a></b> — Reviews the <b>3 Causes</b> of <b>AV Dissociation (</b><i>2/9/2021</i><b>)</b>.</span></span></div><div style="font-family: -webkit-standard; text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></div><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><br /></p><div style="font-family: -webkit-standard; text-align: left;"><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://www.dropbox.com/s/v01yvlqafd5c6z2/AV%20Blocks-Pg%2060-66%20ECG-PB%20%281-16.22-2021%29-USE.pdf?dl=0" target="_blank">Section 2F</a> (</b><i>6 pages = the <b>"<u>short</u>" Answer</b></i><b>)</b> from my ECG-2014 Pocket Brain book provides quick written review of the <b>AV Blocks (</b><i>This is a free download</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><span><b><a href="https://www.dropbox.com/s/k1jk1y4o4uu48ab/20.0-%20ACLS-2013-e-PUB-AV%20Block-Dissociaton-%2810-15.11-2014%29-LOCK.pdf?dl=0" target="_blank">Section 20</a></b> </span><b>(</b><i>54 pages = the <b>"<u>long</u>" Answer</b></i><b>)</b> from my ACLS-2013-Arrhythmias <i>Expanded</i> Version provides <i>detailed</i> discussion of <i>WHAT</i> the <b>AV Blocks</b> are — and what they are <u>not</u>! (<i>This is a free download</i>). </span></li></ul></div></span></div><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><p class="MsoNormal" style="font-family: arial; margin: 0in;"><span style="color: #333333;"></span></p><div class="separator" style="clear: both; font-family: -webkit-standard; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgToTJ6lth3lK5od4oIJM19G0r2sow_0nRRUfJIWtbXsVgI9VRfD_2l6pDgP7KomUFRc9OxYFCdMVG557HCCvVB_1UBm2WrVZA2bq_4rZu3uIWAFGZUsD8V-_ZempjCZoodyin28DOEj7Y/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgToTJ6lth3lK5od4oIJM19G0r2sow_0nRRUfJIWtbXsVgI9VRfD_2l6pDgP7KomUFRc9OxYFCdMVG557HCCvVB_1UBm2WrVZA2bq_4rZu3uIWAFGZUsD8V-_ZempjCZoodyin28DOEj7Y/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div></div><div style="font-family: arial; text-align: justify;"><p class="MsoNormal" style="margin: 0in; text-align: start;"><br /></p><p class="MsoNormal" style="margin: 0in; text-align: start;"><br /></p><p class="MsoNormal" style="margin: 0in; text-align: start;"><br /></p><p class="MsoNormal" style="margin: 0in; text-align: start;"><br /></p></div><div style="font-family: arial; text-align: justify;"><br /></div><div style="font-family: arial; text-align: justify;"><br /></div></span>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-55448757931357130882024-01-13T14:37:00.037-05:002024-01-13T16:50:35.125-05:00ECG Blog #412 — Is Cardiac Cath Indicated? <span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;">The ECG in <b><u>Figure-1</u></b> was obtained from a middle-aged man with known hypertension — who presented to the ED (<i><u>E</u>mergency <u>D</u>epartment</i>) for <b>CP (</b><i><u>C</u>hest <u>P</u>ain</i><b>)</b> over the <b><i>preceding</i></b> <b>2-3 days.</b></div><div style="text-align: justify;">
<p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-style: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px; min-height: 15px;"><br /></p>
<p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-style: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px; min-height: 15px;"><br /></p>
<p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-style: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px;"><b><u>QUESTIONS:</u></b></p><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px;"></p><ul><li><i>How would YOU interpret</i> the ECG in <u>Figure-1</u>?</li><li>Should you <b><i>activate</i></b> <b>the cath lab?</b> If not — <i>What next? </i></li></ul><p></p><div><br /></div></div></span><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMGXxvinGeOJjdMH2Ab9Gri_SmkGzj1xpNdUg9jzf8rdwALm_URVlflT5EvJA9dg_YCypzTxd0mlpGc8LEVOw7Kjl9VIWTuwdprvkikkT64V76_JetNAnu0GKVrEl7Oj_sPOoAJrm9M_TVu05JiVkOMueHI7JQgd6h3zE4EixZrvIKsBSHQV1cCaJOyoc/s3786/Figure-1%20%20ECG-1%20%20(1-10.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1796" data-original-width="3786" height="190" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMGXxvinGeOJjdMH2Ab9Gri_SmkGzj1xpNdUg9jzf8rdwALm_URVlflT5EvJA9dg_YCypzTxd0mlpGc8LEVOw7Kjl9VIWTuwdprvkikkT64V76_JetNAnu0GKVrEl7Oj_sPOoAJrm9M_TVu05JiVkOMueHI7JQgd6h3zE4EixZrvIKsBSHQV1cCaJOyoc/w400-h190/Figure-1%20%20ECG-1%20%20(1-10.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: justify;"><u><span style="color: #333333;">Figure-1:</span></u></b><span style="color: #333333; font-family: arial; text-align: justify;"> The <b><i><u>initial</u></i></b> <b>ECG</b> in today's case — obtained from a middle-aged man with CP for the past 2-3 days. <i>To activate the cath lab?</i></span></span></td></tr></tbody></table></div><div><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="text-align: left;"><b><u><br /></u></b></span></span></div><div style="text-align: justify;"><div><span style="font-family: arial; font-size: medium;"><span style="text-align: left;"><b><u>The <i>Initial</i> ECG in <i>Today’s</i> CASE:</u></b></span></span></div><div><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">The rhythm in <b><u>ECG #1</u></b> is sinus at 65-70/minute. Intervals <b>(</b><i>PR - QRS - QTc</i><b>)</b> are all within normal limits. The axis is slightly leftward <b>(</b><i>at about -10 degrees — as suggested by slight negativity of the small amplitude QRS in lead aVF — but </i></span><span style="font-family: arial; text-align: left; text-decoration: underline;"><i>not</i></span><span style="font-family: arial; text-align: left;"><i> negative enough to qualify as LAHB, because the QRS in lead II is all positive</i><b>)</b>.</span></span></div><div><ul><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><b><i>Voltage</i></b> for <b>LVH</b> is easily satisfied in many leads <b>(</b><i>Very tall R wave in lead I — R in lead aVL ~20 mm</i> [given overlap with the S wave in lead aVR] — <i>deep S waves in V1,V2 + tall R waves in V5,V6 ≥35 mm</i><b>)</b>.</span><span style="font-family: arial; text-align: left;"> </span></span></li><li><span style="font-size: medium;"><span><span style="font-family: arial; text-align: left;">For more regarding <b><i>ECG</i></b> <b>criteria</b> for <b>LVH</b> — See the <i>ADDENDUM</i> below <i>and/or </i></span></span><b style="font-family: arial; text-align: left;"><a href="https://ecg-interpretation.blogspot.com/2013/08/ecg-interpretation-review-73-lvh.html" target="_blank">ECG Blog #73</a> </b><span style="font-family: arial; text-align: left;">and </span><b style="font-family: arial; text-align: left;"><a href="https://ecg-interpretation.blogspot.com/2021/08/ecg-blog-245-59-heart-failure-and-acute.html" target="_blank">ECG Blog #245</a></b><span style="font-family: arial; text-align: left;">.</span></span></li></ul></div><div><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><br /></span></span></div><div><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><i>Regarding</i> <b><u>Q</u>-<u>R</u>-<u>S</u>-<u>T</u> Changes:</b></span></span></div><div><ul><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><b><u>Q</u> Waves</b> — Tiny normal septal q waves in leads I,aVL.</span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><b><u>R</u> Wave Progression</b> — Normal R wave progression — with appropriate transition (<i>where the R wave becomes taller than the S wave is deep</i>) occurring between leads V3-to-V4.</span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><b><u>S</u>T-<u>T</u> Wave Changes</b> — There is ~1 mm of lateral J-point ST depression, with coving of ST segments and deep symmetric T wave inversion <b>(</b><i>seen in leads I,aVL; V4,5,6</i><b>)</b>. There is 1-2 mm of ST elevation in leads III,aVF and V1 — with the T waves in leads III and aVF being disproportionately tall and "bulky" <b>(</b><i>with a mirror-image opposite appearance to the J-point depression and deep T wave inversion seen in lateral leads</i><b>)</b>. </span></span></li></ul></div><div><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><br /></span></span></div><div><span style="font-family: arial; text-align: left;"><b><u><span style="font-size: medium;"><i>MY Impression</i> of ECG #1:</span></u></b></span></div><div><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">As a single tracing in a patient with 2-3 days of CP — this is a difficult ECG to interpret. My thoughts were as follows:</span></span></div><div><ul><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">The rhythm is sinus. </span><b style="font-family: arial; text-align: left;"><i>Marked</i></b><span style="font-family: arial; text-align: left;"> </span><b style="font-family: arial; text-align: left;">LVH</b><span style="font-family: arial; text-align: left;"> is suggested by greatly increased QRS amplitude in multiple leads in this patient with longstanding hypertension <b>(</b><i>See <u>Figure-3</u> in the ADDENDUM below for the ECG criteria for LVH that I favor</i><b>)</b>.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">My written interpretation on a tracing such as this one would read, </span><i style="font-family: arial; font-weight: bold; text-align: left;">"Marked LVH and 'strain' </i><span style="font-family: arial; font-weight: bold; text-align: left;">and/or</span><i style="font-family: arial; font-weight: bold; text-align: left;"> ischemia — with <u>need</u> for clinical correlation." </i></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">Pure LV "strain" tends to produce downsloping ST depression with <i>asymmetric</i> T inversion in ≥1 of the lateral leads <b>(</b>ie, <i>leads I,aVL; V5,V6</i><b>)</b>. Although it is not uncommon in patients with marked hypertension to see deep, symmetric T wave inversion in lateral leads — pure LV "strain" is generally <i><u>not</u></i> associated with ST coving, as is clearly seen in <b>lead V4</b> of <u>ECG #1</u> <b>(</b><i>See <u>Figure-4</u> below in the ADDENDUM for the ECG picture of typical LV "strain" </i><b>)</b>.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">In addition — the ST elevation in l<b>eads III</b> and <b>aVF</b>, in association with the hypervoluminous T waves in these leads — is <i><u>not</u></i> expected with pure LV "strain".</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">On the other hand — the ST elevation seen in <b>lead V1</b> <i><u>is</u></i> perfectly consistent with LVH and LV "strain" <b>(</b>ie, <i>The shape of this ST-T wave in lead V1, in association with the deep S wave in this lead — is a mirror-image opposite picture of the typical expected appearance of LVH with "strain" in a lateral chest lead</i><b>)</b>.</span></span></li><li><u style="font-family: arial; font-weight: bold; text-align: left;"><span style="font-size: medium;"><br /></span></u></li><li><span style="font-size: medium;"><u style="font-family: arial; font-weight: bold; text-align: left;">BOTTOM Line:</u><span style="font-family: arial; text-align: left;"> Today's patient presented with a 2-3 day history of chest pain and the ECG shown in </span><u style="font-family: arial; text-align: left;">Figure-1</u><span style="font-family: arial; text-align: left;">. While this initial ECG is <i><u>not</u></i> diagnostic of an OMI </span><b style="font-family: arial; text-align: left;">(</b><span style="font-family: arial; text-align: left;">ie, <i>of acute coronary </i></span><i><u style="font-family: arial; text-align: left;">O</u><span style="font-family: arial; text-align: left;">cclusion</span></i><b style="font-family: arial; text-align: left;">)</b><span style="font-family: arial; text-align: left;"> — there are enough findings present in <u>ECG #1</u> that are <i><u>not</u></i> expected with simple LVH and "strain", such that <b><i>further evaluation <u>is</u> clearly indicated</i></b>.</span></span></li></ul><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">=============================== </span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>The <span style="color: red;">C</span>ASE <span style="color: red;">C</span>ontinues:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">The first 2 high-sensitivity troponin values returned slightly elevated. A prior ECG from 9 years earlier was found. For ease of comparison — I have put this patient's baseline tracing and his initial ECG in today's case together in <u style="font-weight: bold;">Figure-2</u>.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Does seeing this patient's "baseline" ECG <i><u>change</u></i> your interpretation of <b><u>ECG-1</u></b>?</span></li></ul></div><div style="text-align: justify;"><span style="font-size: medium;"><br /></span></div></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJZLN1gh8TqDaewc-1vEWxcDEELqIrrfS4LOZiAAbrT8M_MmcGuIRECxprqJvPKQCysdnE6AWvC-2sQR457dehkqsplCvH8Hub7qL0hKBKx3smR-vrjsb0vKRdL8vrxlLwk0mB4CxxtCGqkVkmUbsn8ElsifU3iB7vbLG1SwT4tcMonYa-UJrkXGlrakY/s3084/Figure-2%20%20ECGs-1,2%20(1-10.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="2858" data-original-width="3084" height="371" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJZLN1gh8TqDaewc-1vEWxcDEELqIrrfS4LOZiAAbrT8M_MmcGuIRECxprqJvPKQCysdnE6AWvC-2sQR457dehkqsplCvH8Hub7qL0hKBKx3smR-vrjsb0vKRdL8vrxlLwk0mB4CxxtCGqkVkmUbsn8ElsifU3iB7vbLG1SwT4tcMonYa-UJrkXGlrakY/w400-h371/Figure-2%20%20ECGs-1,2%20(1-10.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: justify;"><u><span style="color: #333333;">Figure-2:</span></u></b><span style="color: #333333; font-family: arial; text-align: justify;"> Comparison of the 2 ECGs in today's case.</span></span></td></tr></tbody></table><span style="font-size: medium;"><br /><div style="text-align: justify;"><span style="font-family: arial;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial;"><b><u><i>Comparison</i> of the 2 ECGs in Figure-2:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial;">Availability of a prior tracing on today's patient <i><u>confirms</u></i> that all of the ST-T wave abnormalities described above for <u>ECG #1</u> — are new compared to this patient's baseline tracing done 9 years earlier.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial;">Limb lead QRS amplitudes have greatly increased since the ECG baseline done 9 years earlier.</span></li><li><span style="font-family: arial;">Given the large amplitude of the QRS complex in lead V2 of <u>ECG #2</u> — I found it hard to determine if overall chest lead amplitude was changed.</span></li><li><span style="font-family: arial;">There was <i><u>no</u></i> ST elevation and <i><u>no</u></i> hypervoluminous T waves in leads III and aVF of ECG #2 that was done 9 years earlier.</span></li><li><span style="font-family: arial;">There was <i><u>no</u></i> J-point depression — <i><u>no</u></i> ST segment coving — and <i><u>no</u></i> T wave inversion on the prior ECG.</span></li><li><br /></li><li><span style="font-family: arial;"><b><u>BOTTOM LINE:</u> </b>ECG changes of LV "strain" <i>and/or</i> ischemia that we see on today's initial ECG — were <i><u>not</u></i> present 9 years earlier. That said — We have <i><u>no</u></i> idea when during this 9-year interim period these abnormal ST-T wave findings may have developed.</span></li></ul></div></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div style="text-align: justify;"><span style="font-family: arial;"><b><u><span style="font-size: medium;"><span style="color: red;">C</span>ASE <span style="color: red;">F</span>ollow-<span style="color: red;">U</span>p:</span></u></b></span></div><div style="text-align: justify;"><span style="font-family: arial;"><span style="font-size: medium;">In view of this patient's CP at the time he was seen in the ED — the 2 slightly elevated troponin values — and the <b><i>abnormal</i></b> <b>ST-T wave findings</b> on the <b><i><u>initial</u></i></b> <b>ECG</b> <b>(</b><i>with all of these ST-T wave changes being <u>new</u> since the baseline ECG done 9 years earlier</i><b>)</b> — <b><i>Cardiac cath was performed</i></b>.</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Cardiac cath showed <i><u>normal</u></i> coronary arteries.</span></li><li><span style="font-family: arial; font-size: medium;">Cath pictures <u>and</u> the formal Echocardiogram indicated <b><i>apical</i> HCM (</b><u style="font-style: italic;">H</u><i>ypertrophic </i><u style="font-style: italic;">C</u><i>ardio</i><i><u>M</u>yopathy</i><b>)</b> as the probable etiology of the abnormal ECG in <u>Figure-1</u>.</span></li></ul></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">================================</span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">C</span>OMMENT:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">To emphasize — <b>Cardiac catheterization <i><u>was</u></i> completely appropriate</b> in today's case — as today's patient presented with ongoing CP over the 2-3 days before he arrived in the ED — troponin <u style="font-style: italic;">was</u> elevated (<i>albeit modestly</i>) — and his <b><i><u>initial</u></i></b> <b>ECG</b> <i><u>did</u></i> show ST-T wave changes that suggested <i>"something more"</i> than simple LVH <b>(</b><i>albeit <u>not</u> being overly suggestive of acute coronary occlusion</i><b>)</b>.</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><ul><li><i>Taking another LOOK</i> at today's <b><i><u>initial</u></i></b> <b>ECG (</b><i>and secure with the knowledge from cardiac catheterization that today's patient does <u>not</u> have an acute OMI</i> [ = <i><u>O</u>cclusion-based MI</i>] — <i>but instead has </i><b style="font-style: italic;">apical</b> <b>HCM</b><b>)</b> — the ECG in Figure-1 <i><u>is</u></i> completely consistent with this diagnosis! </li><li>ST-T wave changes in <u>Figure-1</u> are localized to <b><i>lateral</i></b> <b>leads (</b>ie, <i>leads I,aVL; and V4,5,6</i><b>)</b> — especially in leads with increased QRS amplitude. In contrast — with LAD occlusion, there is usually at least modest associated ST elevation in lead aVL (<i>and often also in lead I</i>).</li><li>There is no loss of R wave in anterior leads in Figure-1 (<i>as opposed to poor R wave progression that is commonly seen with LAD OMI</i>).</li><li>The ST-T wave picture in lead V1 of <u>Figure-1</u> is typical of LVH with "strain" <b>(</b>ie, <i>It is the mirror-image opposite picture of what lateral chest leads typically show with marked LVH</i><b>)</b>.</li><li>Rather than Wellens' T waves — the most <i>abnormal</i> appearing chest lead <b>(</b> = <b><i>lead V4</i>)</b> is much more suggestive of a transitional (<i>repolarization</i>) change from the positive ST-T waves in leads V1,2,3 — "on the way" to ST coving and deep T wave inversion seen in the remaining chest leads. <i>Like recognition of a face that you know, but have trouble describing in words — </i>this appearance does <i><u>not</u></i> suggest OMI.</li><li><br /></li><li><u style="font-weight: bold;">P.S.:</u> An additional reason justifying prompt cardiac cath in today's case — is how <i>different</i> the initial ECG in <u>Figure-1</u> looked compared to the "baseline" ECG on file. It would be interesting to see what an Echo from 9 years earlier looked like — but we do not know if such a study was previously done. <b>It therefore appears that this patient's <i><u>apical</u></i> HCM continued to evolve over this 9 year period</b> <b>(</b><i>rendering it impossible to be certain that ST-T wave abnormalities in Figure-1 were all attributable to apical HCM and not acute ischemia</i><b>)</b>.</li></ul></span></div><div><br /></div><div><div style="text-align: justify;"><div><span style="font-family: arial; font-size: medium;">===============================</span></div><div><span style="font-family: arial; font-size: medium;"><b><u><i><span style="color: red;">A</span>bout </i><span style="color: red;">H</span>CM</u> (<i>Different Forms of this Entity</i>):</b></span></div><div><span style="font-family: arial; font-size: medium;">I've excerpted what appears below from <i>My Comment</i> in the <b><a href="https://hqmeded-ecg.blogspot.com/2023/12/an-elderly-patient-with-stuttering.html" target="_blank">December 26, 2023</a> post</b> in Dr. Smith's ECG Blog.</span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-size: medium;"><span style="font-family: arial;"><span><b>HCM</b> is an "umbrella term" </span>applied to the presence of LVH in the absence of "abnormal cardiac loading conditions" <b>(</b><i>Hughes et al</i> — <b><a href="https://www.ahajournals.org/doi/10.1161/JAHA.119.015294" target="_blank">JAHA 9:e015294, 2020</a>)</b>. These are often felt to be the result of autosomal dominant mutations in sarcomeric protein genes — and may present with a number of <b><i><u>distinct</u></i></b> <b>LVH forms</b>, including the <b>"<u>classic</u>"</b> = <b><i>asymmetric</i> septal hypertrophy form </b></span><b style="font-family: arial;">(</b><i style="font-family: arial;">which is the type most commonly referred to when the abbreviation "HCM" is used</i><b style="font-family: arial;">)</b><span style="font-family: arial;"> — concentric HCM — reverse septal — neutral — and </span><b style="font-family: arial;"><i><u>apical</u></i></b><span style="font-family: arial;"> </span><b style="font-family: arial;">HCM (</b><i style="font-family: arial;">initially known as Yamaguchi Cardiomyopathy — and sometimes abbreviated as ApHCM </i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></span></div><div><ul><li><span style="font-size: medium;"><span style="font-family: arial;"><u>Clinically</u> — Overall management of the above different morphological forms of HCM is similar for the emergency provider. That said — distinction between "classic" HCM <i><u>vs</u></i> the <i>apical</i> HCM for</span><span style="font-family: arial;">m may be useful because:</span><b style="font-family: arial;"> i<span style="color: red;">)</span> ECG findings</b><span style="font-family: arial;"> tend to be different <b>(</b><i>Lyon et al </i></span><i style="font-family: arial;">— </i><b style="font-family: arial;"><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6251182/" target="_blank">Europace 20:102-112iii, 2018</a></b><b style="font-family: arial;">)</b><span style="font-family: arial;">; — </span><b style="font-family: arial;">ii<span style="color: red;">)</span></b><span style="font-family: arial;"> </span><b style="font-family: arial;">Echo appearance</b><span style="font-family: arial;"> is different when hypertrophy localizes to the apex; </span><u style="font-family: arial;">and</u><span style="font-family: arial;">, </span><b style="font-family: arial;">iii<span style="color: red;">)</span></b><span style="font-family: arial;"> There is a significantly greater incidence of </span><b style="font-family: arial;">AFib</b><span style="font-family: arial;"> with apical HCM.</span></span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">Beyond the scope of this ECG Blog — specific formal Echo findings may help to sort through the large "spectrum" of HCM disorders — encompassing <b><i>"lower risk"</i> HCM (</b><i>in those with modest or moderate hypertrophy — but <u>without</u> obstruction</i><b>)</b> — vs <i><u>higher</u>-risk </i><b><i>obstructrive</i> forms </b>of HCM.</span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div><b><u><span style="font-family: arial; font-size: medium;"><br /></span></u></b></div><div><b><u><span style="font-family: arial; font-size: medium;">ECG Findings with HCM:</span></u></b></div><div><span style="font-family: arial; font-size: medium;">Most patients with HCM do <i><u>not</u></i> have a normal ECG. Among the many <b>ECG findings</b> that may be seen in patients with <b><i>"<u>classic</u>"</i></b> <b>HCM</b> are the following:</span></div><div><ul><li><span style="font-family: arial; font-size: medium;">Increases in QRS amplitude.</span></li><li><span style="font-family: arial; font-size: medium;">Large septal Q waves (<i>Sometimes known as "dagger" Q waves — because these are deep but narrow Q waves seen in lateral leads</i>). </span></li><li><span style="font-family: arial; font-size: medium;">Tall R wave in lead V1 <i>and/or</i> early transition in the chest leads (<i>reflecting increased "septal" forces</i>).</span></li><li><span style="font-family: arial; font-size: medium;">Abnormal ST-T wave abnormalities.</span></li><li><span style="font-family: arial; font-size: medium;">Conduction defects (ie, <i>LBBB, IVCD</i>).</span></li><li><span style="font-family: arial; font-size: medium;">WPW </span></li><li><span style="font-family: arial; font-size: medium;">Cardiac arrhythmias (<i>including AFib</i>). </span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><b><u>The Problem:</u></b> <i>None </i>of the above ECG findings are specific for HCM. The variety of potential ECG findings with "classic" HCM is great — which poses problems when contemplating whether or not to use the ECG as a screening tool in athletes.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div><b><u><span style="font-family: arial; font-size: medium;">ECG Findings with <i>Apical</i> HCM:</span></u></b></div><div><span style="font-family: arial; font-size: medium;"><i>Apical </i>HCM makes up a minority of patients who qualify as having "HCM" (ie, <i>less than 10% in the non-Asian population</i><b>)</b>. </span></div><div><ul><li><span style="font-family: arial; font-size: medium;">With the exception "dagger" Q waves (<i>which are typically a result of a thickened septum</i>) — any of the other ECG findings listed above for "classic" HCM may be seen with <i>apical</i> HCM.</span></li><li><span style="font-family: arial; font-size: medium;">The ECG finding that is most characteristic of apical HCM is the presence of <b><i><u>Giant</u></i> T waves</b>. Although T wave inversion in <u>ECG #1</u> is prominent — it is <i><u>not</u></i> quite deep enough to qualify as true "Giant" T waves <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2022/01/ecg-blog-276-81-what-about-those-t-waves.html" target="_blank">ECG Blog #276</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2022/05/ecg-blog-309-syncope-and-wellens.html" target="_blank">ECG Blog #309</a>).</b></span></li></ul></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">======================</span></div><div><span style="font-size: medium;"><span style="font-family: arial;"><b><u>NOTE:</u></b> For more on <b>HCM</b>, with a summarizing Table on the <i><u>treatment</u></i> approach to this group of disorders — Please check out <i>My Comment</i> i</span><span style="font-family: arial;">n the </span><b style="font-family: arial;"><a href="https://hqmeded-ecg.blogspot.com/2023/10/continuous-prolonged-generalized.html" target="_blank">October 28, 2023</a> post </b><span style="font-family: arial;">in Dr. Smith's ECG Blog.</span></span></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">======================================</span></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==============================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to <span style="background: repeat white; color: #050505; text-align: start;">林柏志</span><span face="-webkit-standard" style="font-size: medium; text-align: start;"></span> (<i>from Taiwan</i>) for the case and this tracing.<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;">==================================<o:p></o:p></span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;"> </span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><i><u>Related</u></i></b><b><u> ECG Blog Posts to <i>Today’s</i> Case: <o:p></o:p></u></b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><ul><li><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b><span>— Reviews my </span><b><i>Systematic</i></b><span> </span><b>Approach</b><span> to 12-lead ECG Interpretation </span><b>(</b><i>outlined in Figures-2 and -3, and the subject of <b><u>Audio</u></b></i><span> </span><b>Pearl MP-23</b><span> </span><i>in Blog #205</i><b>)</b><span>.</span></span></li><li><b><span style="font-family: arial; font-size: medium;"> </span></b></li><li><span style="font-size: medium;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-209-ecg-mp-26-is-this-wellens.html" target="_blank">ECG Blog #209</a></b><span> — and <b><a href="https://ecg-interpretation.blogspot.com/2021/10/ecg-blog-254-26a-wellens-syndrome.html" target="_blank">ECG Blog #254</a></b> — Reviews a case of <b><i>marked</i></b> <b>LVH</b> that results in <i><u>similar</u></i> S</span></span><span style="font-family: arial;">T-T wave changes as may be seen with </span><b style="font-family: arial;"><i>Wellens'</i></b><span style="font-family: arial;"> </span><b style="font-family: arial;">Syndrome</b><span style="font-family: arial;">.</span></span></li><li><b><span style="font-family: arial; font-size: medium;"> </span></b></li><li><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/08/ecg-blog-245-59-heart-failure-and-acute.html" target="_blank">ECG Blog #245</a></b><span> — Reviews the ECG diagnosis of <b>LVH</b></span></span><span style="font-family: arial; font-size: large;">.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial;"><span style="font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2022/01/ecg-blog-276-81-what-about-those-t-waves.html" target="_blank">ECG Blog #276</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2022/05/ecg-blog-309-syncope-and-wellens.html" target="_blank">ECG Blog #309</a></b> — Reviews the entity of <b><i><u>Giant</u></i> T waves</b>.</span></span></li></ul><div><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2013/08/ecg-interpretation-review-73-lvh.html" target="_blank">ECG Blog #73</a></b> — Reviews <i>"My Take"</i> on the ECG Diagnosis of <b>LVH</b>.</span><b><span style="font-family: arial; font-size: medium;"> </span></b></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2014/06/ecg-blog-92-basic-concepts-5-lvh.html" target="_blank">ECG Blog #92</a></b><span> </span><span>— Presents another perspective for ECG Diagnosis of</span><span> </span><b>LVH</b><span>.</span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span>The</span><b> <a href="https://hqmeded-ecg.blogspot.com/2018/11/chest-pain-and-q-waves-in-v1-and-v2-is.html" target="_blank">November 4, 2018</a> post</b><span> </span><span>in Dr. Smith's ECG Blog — My Comment (</span><i>at the bottom of the page</i><span>) reviews 3 ECG Clues for</span><span> </span><b><i>rapid</i></b><span> </span><b>recognition</b><span> </span><span>of</span><span> </span><b><i>erroneous</i></b><span> </span><b>lead V1,V2 placement</b><span>.</span><span> </span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span>The</span><b> <a href="https://hqmeded-ecg.blogspot.com/2019/03/three-ekgs-shown-to-me-which-if-any.html" target="_blank">March 31, 2019</a> post</b><span> </span><span>in Dr. Smith's ECG Blog — My Comment (</span><i>at the bottom of the page</i><span>) illustrates the potentially misleading effect the pre-hospital ECG may have in patients with <b>LVH</b>, by</span><span> </span><b><i>cutting off</i></b><span> </span><b>S wave voltage</b><span> </span><span>in the</span><span> </span><b><i>anterior</i></b><span> </span><b>leads</b><span>.</span><span> </span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span>The</span><b> <a href="http://hqmeded-ecg.blogspot.com/2019/03/epigastric-pain-radiating-to-chest-for.html" target="_blank">March 29, 2019</a> post</b><span> </span><span>in Dr. Smith's ECG Blog — My Comment regarding Tracing A (</span><i>at the bottom of the page</i><span>) illustrates how</span><span> </span><b>LVH</b><span> </span><span>is a common</span><span> </span><b><i>mimic</i></b><span> </span><span>of</span><span> </span><b><i>acute</i></b><span> </span><b>ischemia</b><span>.</span><span> </span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span>The</span><span> </span><b><a href="http://hqmeded-ecg.blogspot.com/2018/12/profound-st-elevation-in-v1-v3-what-do.html" target="_blank">December 27, 2018</a> post</b><span> </span><span>in Dr. Smith's ECG Blog — My Comment (</span><i>at the bottom of the page</i><span>) illustrates a case with</span><span> </span><b><i>anterior</i></b><span> </span><b>ST elevation <i>from</i> LVH</b><span> </span><span>that may falsely suggest acute anterior infarction.</span></span></li></ul></div><p></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><br /></p><div><br /></div><div><span style="font-family: arial; font-size: large; text-align: justify;">=======================================</span></div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">A</span>DDENDUM</u> <span style="color: red;">(</span></b>1/13/2024<b><span style="color: red;">)</span>:</b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><span>I've added below in </span><b><u>Figure-3</u></b><span> and </span><b><u>Figure-4</u></b><span> additional material to facilitate ECG diagnosis of LVH and LV "strain".</span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://dl.dropbox.com/s/gcfkydrk14nvk7b/z-ECG-Audio%20Pearl-59%20LVH%20%288-17.1-2021%29-USE.mp3?dl=0" target="_blank"><span style="font-family: arial; font-size: medium;">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1446" data-original-width="2048" height="283" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiHGni42QwRfyhm-6zHQNgZwYRxluZsl4m9rmGWxplOtd2WCzIskAggXaO-_cnuv7ZDt5_NoOvvV9afGizf5TY0_UkrWULqnrA2GxaEFigHxx1hyphenhyphenTH5YCphRjh0z3zMcssiLI7mY1ts_dE/w400-h283/ECG-MP-59+-+LVH+%25288-18.21-2021%2529-USE.png" width="400" /></span> —</span></a></div><p></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>59 (</b><i>9:10 minutes</i> <b><i><u>Audio</u></i>)</b> — Reviews the ECG diagnosis of <b><span style="color: red;">L</span>VH (</b><i>and its impact clinically with both chronic and acute cardiac disorders</i><b>)</b>.</span></p><p class="MsoNormal" style="margin: 0in; text-align: right;"><br /></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"></span></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh04rZM00If89NizyBnjUfqpnvOD1MnSfiqQObvYZZJSU6gw7Bmn20Hs7j8hnoLaZprxPUsrNED9shVWru6htM6w3gg5woRDc7MUNc32AJSZ5QN17mxM7SKZJJ_36UGaN_j9dyx7pLGB7o/s2048/Figure-3+Criteria+for+LVH+%25288-16.1-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2048" data-original-width="1733" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh04rZM00If89NizyBnjUfqpnvOD1MnSfiqQObvYZZJSU6gw7Bmn20Hs7j8hnoLaZprxPUsrNED9shVWru6htM6w3gg5woRDc7MUNc32AJSZ5QN17mxM7SKZJJ_36UGaN_j9dyx7pLGB7o/w339-h400/Figure-3+Criteria+for+LVH+%25288-16.1-2021%2529-USE.png" width="339" /></span></a></td></tr><tr><td class="tr-caption"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #333333;">Figure-3:</span></u></b><span style="color: #333333; text-align: justify;"> The voltage and other criteria I favor for ECG diagnosis of <b>LVH (</b><i>Please see</i> <b><a href="https://ecg-interpretation.blogspot.com/2013/08/ecg-interpretation-review-73-lvh.html" target="_blank">ECG Blog #73</a></b> <i>for additional details</i><b>)</b>.</span></span></td></tr></tbody></table><p></p><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="color: #333333; text-align: left;"><span style="font-family: arial;"></span></span></span></p><p style="text-align: left;"></p><p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKCYCk39vs05EJLVW7ByMtv8jFMUH7aJFTdB5GLT_aIX0KDWwaaAJS46Xpbwlw5I0G6iosbGq8KCYoI8UtuMd2X9f2MMH617b7Qtm1sLvbdZfDZiTDTPczrNPi79rSDaEFOPd3Mq-tvd4/s2674/Figure-4+LV+Strain+%25288-18.1-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1034" data-original-width="2674" height="155" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKCYCk39vs05EJLVW7ByMtv8jFMUH7aJFTdB5GLT_aIX0KDWwaaAJS46Xpbwlw5I0G6iosbGq8KCYoI8UtuMd2X9f2MMH617b7Qtm1sLvbdZfDZiTDTPczrNPi79rSDaEFOPd3Mq-tvd4/w400-h155/Figure-4+LV+Strain+%25288-18.1-2021%2529-USE.png" style="cursor: move;" width="400" /></span></a></td></tr><tr><td class="tr-caption"><span style="font-size: medium;"><b style="text-align: justify;"><u><span style="color: #333333;"><span style="font-family: arial;">Figure-4:</span></span></u></b><span style="color: #333333; text-align: justify;"><span style="font-family: arial;"> ST-T wave appearance of normal (<b>A</b>) — <u>vs</u> "strain" (<b>C</b>) or a strain "equivalent" pattern (<b>B</b>) — <u>vs</u> ischemia (<b>D</b>). <b>(</b><i>Please see</i> <b><a href="https://ecg-interpretation.blogspot.com/2013/08/ecg-interpretation-review-73-lvh.html" target="_blank">ECG Blog #73</a></b> <i>for additional details</i><b>)</b>.</span></span></span></td></tr></tbody></table><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgxvR_hZ2qJaLennxhfBOtmEZlkZ9YApFE4eDbAD8D8TCpK4fnFS3vHmH3wNzPVe3tjdsl6nnmx5bGPfyQfCSmyPXCLrn9GXFPnObayXOTru25iDO7OMb1vIl9-O7-Xptlj-vwFn0Z2oxE/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgxvR_hZ2qJaLennxhfBOtmEZlkZ9YApFE4eDbAD8D8TCpK4fnFS3vHmH3wNzPVe3tjdsl6nnmx5bGPfyQfCSmyPXCLrn9GXFPnObayXOTru25iDO7OMb1vIl9-O7-Xptlj-vwFn0Z2oxE/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div style="text-align: justify;"><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; font-family: -webkit-standard; text-align: right;"><span style="font-family: arial; font-size: medium;"><br /></span></div><span style="font-family: arial; font-size: medium; text-align: left;"></span></div></div></span></div></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-65128875840625737962024-01-06T00:03:00.000-05:002024-01-06T00:03:57.380-05:00ECG Blog #411 — Is it Wenckebach? <div><br /></div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><i>How would YOU interpret </i>the tracing in <u style="font-weight: bold;">Figure-1</u> — that was sent to me without additional information?</div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>QUESTIONS:</u></b></div><div style="text-align: justify;"><ul><li><b><i>What is the rhythm?</i></b></li><li>Is there AV dissociation? If so — <i>WHY?</i></li><li><i><br /></i></li><li><u>Clinically</u> — <i>HOW </i>would you approach interpretation of this tracing in <b>optimal <i><u>time</u>-efficient </i>fashion?</b></li></ul></div></span><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjd8CT3cRQYdY0tOuV6HU1GcABalpMVlk8PZy1_2F5D4aR0DKI8XJxpn-E5-z7QvhfJRyZBiSpKWGQ03YrzFKQmAdaHAvmLlFCzspcpCngwaOqYGpm9nYMvkn9gQKW4ML8ws9iBldcfq1kX3Tq5exk5wxxln7x8CNHXn3qT-sN8bOz1PjnFmooPY3vngk/s3782/Figure-1%20%20ECG-1%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2058" data-original-width="3782" height="217" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjd8CT3cRQYdY0tOuV6HU1GcABalpMVlk8PZy1_2F5D4aR0DKI8XJxpn-E5-z7QvhfJRyZBiSpKWGQ03YrzFKQmAdaHAvmLlFCzspcpCngwaOqYGpm9nYMvkn9gQKW4ML8ws9iBldcfq1kX3Tq5exk5wxxln7x8CNHXn3qT-sN8bOz1PjnFmooPY3vngk/w400-h217/Figure-1%20%20ECG-1%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: left;"><u>Figure-1:</u></b><span style="text-align: left;"> The <b><i><u>initial</u></i></b> <b>ECG</b> in today's case.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><u>KEY <i>Clinical</i> Point:</u></b></span></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">If I was the medical provider charged with the care of the patient whose ECG is shown in </span><u style="font-family: arial; text-align: left;">Figure-1</u><span style="font-family: arial; text-align: left;"> — I would approach this tracing in the following<b> <i><u>sequential</u></i> stages:</b></span></span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">I’d first establish that the patient was <b><i><u>hemodnamically</u></i></b> <b>stable</b> with this ECG and this cardiac rhythm. </span><i style="font-family: arial; text-align: left;">Assuming this patient <u>is</u> at least momentarily stable</i><span style="font-family: arial; text-align: left;"> — I’d then proceed as follows:</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><br /></span></span></li><li><span style="font-size: medium;"><i style="font-family: arial; text-align: left;">I’d take a quick look at the long lead rhythm strip</i><span style="font-family: arial; text-align: left;">. </span></span></li><li><span style="font-size: medium;"><u style="font-family: arial; font-weight: bold; text-align: left;">To EMPHASIZE:</u><span style="font-family: arial; text-align: left;"> The rhythm shown in the long lead II <b>(</b><i>below the 12-lead tracing in </i></span><u style="font-family: arial; text-align: left;">Figure-1</u><span style="font-family: arial; text-align: left;"><b>) </b>is <i><u>not</u></i> a simple arrhythmia — so rather than trying to come up with a precise interpretation of the rhythm —<b> I’d spend <i><u>no</u></i> <u>more</u> than 5-to-10 seconds </b>to ensure there is a reasonable, stable-looking heart rate <b>(</b><i>which there </i><u style="font-style: italic;">is</u><i> in Figure-1 — as the rhythm is </i><b><i>supraventricular </i>[</b><i><u>narrow</u> QRS everywhere</i><b>] </b>— some <b>P waves</b> <u style="font-style: italic;">are</u> seen — <u>and</u>, <i>a pattern of repetitive </i><u style="font-style: italic;"><b>group</b></u><i> </i><b>beating (</b><i>groups of 3 beats</i><b>)</b><i>, with an average heart rate in the</i><i style="font-weight: bold;"> 60-80/minute rate range </i>—<b> </b><i>appears to be present</i><b>)</b>.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><br /></span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><b>I’d then spend <u style="font-style: italic;">no</u> <u>more</u><i> </i>than 5-to-10 seconds</b> looking at the rest of the 12-lead ECG to ensure that there is <u style="font-style: italic;">no</u> ongoing emergency in need of <i>immediate</i> care <b>(</b>ie, <i>No acute MI; No hyperkalemia, etc.</i><b>)</b>.</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>COMMENT:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">While I always advocate a <b><i><u>systematic</u></i></b> <b>approach</b> to <i><u>both</u></i> rhythm and 12-lead ECG interpretation — optimal clinical ECG interpretation entails <i><u>prioritizing</u></i> those parts of the tracing in front of you that mandate your <i>immediate</i> attention. Later, <i>when you have a moment of time</i> — You can complete your systematic assessment.</span></span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><u>With Regard to the <i>Cardiac</i> Rhythm:</u> Our <b><i>initial</i></b> <b>5-to-10 second assessment</b> of the long lead II rhythm strip should be all that is needed at this instant in time — because this limited amount of time should still allow you to establish: </span><b style="font-family: arial; text-align: left;">i<span style="color: red;">)</span></b><span style="font-family: arial; text-align: left;"> That the patient <i><u>is</u></i> hemodynamically stable; <u>and</u>, </span><b style="font-family: arial; text-align: left;">ii<span style="color: red;">)</span></b><span style="font-family: arial; text-align: left;"> That the rhythm <i><u>is</u></i> supraventricular — with at least <i>some</i> P waves, a <i>narrow</i> QRS everywhere — <u>and</u>, an overall heart rate in the 60-80/minute range.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><br /></span></span></li><li><span style="font-size: medium;"><span><u style="font-family: arial; font-weight: bold; text-align: left;">PEARL <span style="color: red;">#</span>1</u><span style="font-family: arial; font-weight: bold; text-align: left;"> (</span><span style="font-family: arial; text-align: left;"><i><u>Advanced</u> Point</i><b>): </b></span><span style="font-family: arial; text-align: left;">The fact that the QRS complex is narrow, with at least <i>some</i> P waves — and a pattern suggesting <b><i><u>group</u></i></b> <b>beating</b> — should clue us into: <b>i<span style="color: red;">)</span> </b>The possibility of <b><i>Wenckebach</i></b> <b>conduction!</b> </span></span><span style="font-family: arial; text-align: left;">— </span><u style="font-family: arial; text-align: left;">and</u><span style="font-family: arial; text-align: left;">, </span><b style="font-family: arial; text-align: left;">ii<span style="color: red;">)</span> </b><span style="font-family: arial; text-align: left;">That we need to carefully inquire about recent chest pain, </span><span style="font-family: arial; text-align: left;">paying special attention to the rest of this 12-lead ECG </span><b style="font-family: arial; text-align: left;">(</b><i style="font-family: arial; text-align: left;">looking carefully for signs of acute or recent infarction — because AV Wenckebach is common with acute inferior MI</i><b style="font-family: arial; text-align: left;">)</b><span style="font-family: arial; text-align: left;">. It is <u style="font-style: italic;">much</u> easier to identify Wenckebach conduction IF you are looking for it!</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>Regarding</i> the <span style="color: red;">1</span>2-<span style="color: red;">L</span>ead <span style="color: red;">E</span>CG:</u></b> </span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Applying the <u style="font-style: italic;">systematic</u> approach I favor for <b>12-lead ECG interpretation</b> <b>(</b><i>as detailed in </i><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a>):</b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><b><u>Rate & Rhythm:</u> </b>As stated above — there is a regular, supraventricular rhythm with some P waves, group beating, and an acceptable overall ventricular rate between ~60-80/minute.</span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">Intervals</u><span style="font-weight: bold;"> (<i>PR-QRS-QTc</i>):</span> The PR interval varies — the QRS is narrow — the QTc looks normal (<i>Best seen in leads V2,V3</i>). </span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">Axis:</u> Normal (<i>about +60 degrees</i>).</span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">Chamber Enlargement:</u> Depending on age of the patient — voltage for LVH may be present <b>(</b>ie, <i>Deepest S in V1,V2 + tallest R in V5,V6 ≥35 mm — IF the patient is ≥35 years of age</i><b>)</b>.</span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div><span style="font-size: medium;"><span style="font-family: arial;"><span><b><i>Regarding </i></b></span><u style="font-weight: bold;">Q</u><span style="font-weight: bold;">-<u>R</u>-<u>S</u>-<u>T</u> Changes</span><span style="font-weight: bold;">:</span> </span><br /></span><ul><li><span style="font-family: arial; font-size: medium;"><b><u>Q</u> waves: </b>Small q waves of uncertain significance are seen in the inferior leads.</span></li><li><span style="font-family: arial; font-size: medium;"><b><u>R</u> Wave Progression:</b> Normal, with transition (<i>where height of the R wave becomes taller than the S wave is deep</i>) — occurs normally, here by lead V4.</span></li><li><span style="font-family: arial; font-size: medium;"><b><u>S</u>T-<u>T</u> wave Changes:</b> Show some <i>nonspecific</i> ST-T wave flattening, and perhaps shallow T wave inversion in lead aVL. The slight amount of ST elevation that we see in lead V2 is common and normal.</span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;"><i>Clinical </i>IMPRESSION:</u> The ECG in <u>Figure-1</u> shows <i>nonspecific</i> ST-T wave abnormalities — but <u style="font-style: italic;">nothing</u> that looks acute.</span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">==================================</span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">L</span>ooking <i><span style="color: red;">C</span>loser</i> at the <span style="color: red;">R</span>hythm in <i>Today's</i> CASE:</u></b></span></div><div><span style="font-family: arial; font-size: medium;">As reviewed in <b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a> </b>— I favor the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach</b> for <i><u>systematic</u></i>, time-efficient interpretation of the cardiac rhythm.</span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><b><u>PEARL <span style="color: red;">#</span>2:</u></b> When looking for P waves — I find it easiest to first identify those P waves that I am <u style="font-style: italic;">certain</u> about. I have done this with <i>RED arrows</i> in <u style="font-weight: bold;">Figure-2</u>.</span></li><li><span style="font-family: arial; font-size: medium;">The presence of multiple, regularly-spaced <i>RED </i>(<i> = definitely present</i>)<i> </i>P waves in <u>Figure-2</u> suggests: <b>i<span style="color: red;">)</span> </b>that there is a very good chance that the underlying atrial rhythm will be regular throughout the long lead II rhythm strip; <u>and</u>, <b>ii<span style="color: red;">)</span> </b>that the P-P interval between <u style="font-style: italic;">any</u> 2 consecutive <i>RED arrows </i>will clue us in to where the remaining (<i>partially hidden</i>) P waves can be found. </span></li><li><span style="font-family: arial; font-size: medium;">Use of <u style="font-style: italic; font-weight: bold;">calipers</u> can facilitate <i>confirming</i> that <b>the <i>underlying</i> atrial rhythm</b> in <u>Figure-2</u> <b>is</b> <b><i>in fact</i></b> <b>regular</b>. <i>With calipers — it takes </i><i><u>only</u> seconds to confirm this!</i></span></li><li><span style="font-family: arial; font-size: medium;"><i>PINK arrows</i> highlight that the on-time beginning little "hump" at the very onset of the QRS of beats #2 and #5 clearly represents 2 additional <i>on-time</i> P waves.</span></li><li><span style="font-family: arial; font-size: medium;">Completion of our <i>"P wave search"</i> can then be easily accomplished by noting the <i>subtle-but-unmistakeable distortion</i> under the <i>PURPLE arrows </i>toward the end of the T waves of beats #1 and 4 — and at the very onset of the QRS of beats #8 and #11.</span></li></ul></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjymtAvaEcLsJxOtFSFupYUnmxLRpPcTWZ_swPU4-JACaIY-XxeY2JZqh1dHR7Z2_ShQS1tSZGW5JrMqntsvtrxcDi0BvV_ifdFOlJB02a-SI48lOHMqx_pvLkb3s_UQDUrILh54MiBoNAJr4Uo8hQIwH7Dc42QQtLfTqMTUA8wUJxruIM1hM_qgx3sTCo/s3794/Figure-2%20%20ECG-1-P%20waves%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2038" data-original-width="3794" height="215" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjymtAvaEcLsJxOtFSFupYUnmxLRpPcTWZ_swPU4-JACaIY-XxeY2JZqh1dHR7Z2_ShQS1tSZGW5JrMqntsvtrxcDi0BvV_ifdFOlJB02a-SI48lOHMqx_pvLkb3s_UQDUrILh54MiBoNAJr4Uo8hQIwH7Dc42QQtLfTqMTUA8wUJxruIM1hM_qgx3sTCo/w400-h215/Figure-2%20%20ECG-1-P%20waves%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: left;"><u>Figure-2:</u></b><span style="text-align: left;"> I've labeled atrial activity in today's tracing with colored arrows (<i>See text</i>).</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;"><u style="font-weight: bold;"><br /></u></div><div style="text-align: justify;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>3:</u> Recognition that <b>true <i><u>group</u></i> <u>beating</u></b> is present, in association with an underlying <i>regular</i> atrial rhythm — strongly suggests there is some type of <b>2nd-degree AV block</b> in which there is <b><i>Wenckebach</i></b> <b>conduction (</b>ie, <i>the presence of an underlying regular P wave rhythm is an essential component of the typical forms of AV block</i><b>)</b>. </div><div style="text-align: justify;"><ul><li>Focus on this concept facilitates recognizing the <b>3 <i><u>true</u></i> groupings</b> in <b><u>Figure-3</u> (</b><i>within the dotted WHITE rectangles</i><b>)</b>. Note the uncanny similarity in duration of the R-R interval between the first 2 beats in each group <b>(</b>ie, <i>the R-R interval between beats #2-3; 5-6; and 8-9</i><b>)</b> — as well as for the R-R interval between the last 2 beats in each group <b>(</b>ie, <i>the R-R interval between beats #3-4; 6-7; and #9-10</i><b>) </b>— as well as for duration of the R-R intervals of the short pauses that separate each of the groups <b>(</b>ie, <i>the R-R interval between beats #1-2; 4-5; 7-8; and 10-11</i><b>)</b>. This amount of symmetry for the relative duration of R-R intervals within each group of beats <b>is <i style="text-decoration: underline;">not</i> the result of chance!</b></li></ul><div style="text-align: center;"><br /></div><div style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglcfB1n1hl1zIGHUqGsIdZe23aXv3ABQt4W8xUU2ljrPAIAY4IUO4Eq7oKAf8bxQSqdD5Nhf4YQakuQx56wDD_zi6CAlbsgaDW3Npz_8SkUDBschl45WL1fJ6QsUuCcUX1uDZxQJOhsTiShPhB7C-KQRYqqSoa8FU0Ayyddj3Nw6MBsuXkHXWVo3Hxv6g/s3790/Figure-3%20Lead%20II-P%20waves%20(1-2.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="600" data-original-width="3790" height="64" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglcfB1n1hl1zIGHUqGsIdZe23aXv3ABQt4W8xUU2ljrPAIAY4IUO4Eq7oKAf8bxQSqdD5Nhf4YQakuQx56wDD_zi6CAlbsgaDW3Npz_8SkUDBschl45WL1fJ6QsUuCcUX1uDZxQJOhsTiShPhB7C-KQRYqqSoa8FU0Ayyddj3Nw6MBsuXkHXWVo3Hxv6g/w400-h64/Figure-3%20Lead%20II-P%20waves%20(1-2.21-2024)-USE.png" width="400" /></a></div><div style="text-align: center;"><span style="font-size: medium;"><b style="text-align: left;"><u>Figure-3:</u></b><span style="text-align: left;"> <i>RED arrows</i> highlight that the atrial rhythm in the long lead II rhythm strip <u style="font-style: italic;">is</u> regular. Note the <b>3 <i><u>true</u></i> groupings (</b><i>within the dotted WHITE rectangles</i><b>)</b>.</span></span></div><div><span style="font-size: medium;"><span style="text-align: left;"><br /></span></span></div><div><span style="font-size: medium;"><span style="text-align: left;"><br /></span></span></div><b><u>PEARL <span style="color: red;">#</span>4:</u></b><b> </b>We <u style="font-style: italic;">know</u> that there is at least <b><i><u>transient</u></i> AV Dissociation</b> in today's rhythm — because the PR interval of some <i>on-time</i> sinus P waves is clearly too short to be able to conduct <b>(</b>ie, <i>Despite their <u>on</u>-<u>time</u> occurrence — the WHITE arrow P waves before beats #2,5,8 and 11 in </i><u style="font-weight: bold;">Figure-4</u> —<i> do <u>not</u> have enough time for normal conduction through the AV node</i><b>)</b>.<br /><ul><li>Since <b>beats #2,5,8 </b>and<b> 11</b> all manifest a <i>narrow</i> QRS complex — and are <u style="font-style: italic;">not</u> preceded by sinus P waves with a realistic chance of conducting — this means that these 4 QRS complexes are <b><u style="font-style: italic;">junctional</u> beats</b>.</li><li>Note that each of these beats is preceded by a similar R-R interval of just <i>under</i> 5 large boxes — which corresponds to an <i>ever-so-slightly</i> <b>accelerated <i><u>junctional</u></i> escape rate</b> of <b>~65/minute</b>.</li><li>That said — We have <u style="font-style: italic;">no</u> idea if the <i>WHITE-arrow </i>P waves that appear at the onset of the QRS of beats #2,5,8 and 11 might possibly have conducted — IF they were given a chance to do so <b>(</b>ie, <i>IF the junctional escape rate would have been slower than 65/minute</i><b>)</b>.</li></ul><div style="text-align: justify;"><br /></div><b><u>PEARL <span style="color: red;">#</span>5:</u></b> Despite the presence of <i>at least</i> transient AV dissociation — the rhythm in Figure-4 is <u style="font-style: italic;">not</u> complete AV Block.<br /><ul><li><b>Most of the time when there is <i><u>complete</u></i> AV block — the escape rate</b> <b>(</b><i>be this a junctional or ventricular escape rhythm</i><b>)</b> <b>will be </b><u style="font-weight: bold;">regular</u>. The obvious irregularity of the ventricular response in <u>Figure-4</u> — immediately tells us this is <i><u>not</u></i> complete AV block.</li><li><b>QRS complexes </b>that occur <i style="font-weight: bold;">earlier-than-expected</i> are likely to be conducted beats! <b>(</b>ie, <i>Beats #4,7 and 10 in Figure-4 are therefore likely to be conducted — and beats #3,6,9 and 12 may also be conducted</i><b>)</b>.</li></ul><div><br /></div><div><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>6:</u> As per PEARL #4 — we have already established that there is <i>transient</i> AV dissociation in <u>Figure-4</u> (<i>because beats #2,5,8,11 are clearly <u>not</u> conducted</i>). There appear to be 2 reasons for this <b><i><u>transient</u></i></b> <b>AV dissociation</b> in today's rhythm:</div><ul><li>As reviewed in <b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" target="_blank">ECG Blog #192</a></b> — the <b>3 <u>Causes</u></b> of <b>AV Dissociation</b> are: <b>i<span style="color: red;">)</span> Default</b>; <b>ii<span style="color: red;">)</span> Usurpation</b>; <u>and</u>, <b>iii<span style="color: red;">)</span> </b>Some form of <b>2nd-</b> or <b>3rd-degree AV block</b>. </li><li>Today's tracing is interesting — in that the reason for transient AV dissociation <b>(</b>ie,<i> non-conduction of the WHITE-arrow P waves in Figure-4</i><b>)</b> — appears to be a <u style="font-style: italic;">combination</u> of the <b>slightly <i>accelerated</i> junctional beats (</b><i>beats #2,5,8 and 11</i><b>)</b> — and the <b>2nd-degree AV block</b> that leads to the slight pauses after beats #1,4,7 and 10.</li></ul><div style="text-align: justify;"><br /></div><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>7:</u> Looking closer in <u>Figure-4</u> at the P waves in each of the 3-beat groupings — tells us that there is <b>2nd-degree AV block, Mobitz Type I (</b><i><b> </b>= AV Wenckebach</i><b>) </b>because of the following findings<b>:</b><br /><ul><li>As already stated — the <i>WHITE-arrow</i> P waves in each group do <u style="font-style: italic;">not</u> conduct to the ventricles — because the PR interval is too short.</li><li>That said — We <u style="font-style: italic;">know</u> that the <i>next</i> P wave in each grouping <b>(</b>ie, <i>the light BLUE-arrow P waves</i><b>)</b> — <i><u>does</u></i> conduct to the ventricles, because <b>the PR interval preceding beats #3,6,9 and 12 are all equal!</b></li><li>This is followed by the <i>dark BLUE-arrow</i> P waves that are <u style="font-style: italic;">also</u> conducting — but with slight increase in the PR interval compared to the <i>light BLUE</i> PR interval. Once again — We <u style="font-style: italic;">know</u> that the <i>dark BLUE-arrow </i>P waves are conducting — because <b>the PR interval preceding beats #4,7 and 10 are all equal!</b></li><li>The last P wave in each grouping <b>(</b>ie, <i>the YELLOW-arrow P waves</i><b>)</b> — are non-conducted — thus completing the AV Wenckebach cycle of <b><i>progressive</i> PR interval lengthening until a beat is dropped</b>.</li><li><br /></li><li>Additional typical features of <b>AV Wenckebach</b> in <u>Figure-4</u> include: <b>i<span style="color: red;">)</span></b> The narrow QRS <b>(</b><i>Mobitz II usually has a wide QRS — because of its origin at a lower point in the conduction system</i><b>)</b>; <b>ii<span style="color: red;">)</span> </b>Progressive shortening of the R-R interval within groups <b>(</b><i>the R-R intervals between beats #3-4; 6-7; and 9-10 — are shorter than the R-R intervals between beats #2-3; 5-6; 8-9</i><b>)</b>; <u>and</u>, <b>iii<span style="color: red;">)</span> </b>The pause containing the dropped beat is <u style="font-style: italic;">less</u> than twice the shortest R-R interval.</li></ul></div></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhOwVfEcle9sYzP3cBHQP7FWaleRtbh9fnGh_QeBqf3c9KQAVly2Uc0QeT7zGuQf0pJ5kvC3pUjYg9Pog_pleS7aRc-fjDdWdORBjzW5kNEI9BBVpYXlewTTV7aI6n-IQRI6zWYCpWxdsh0DFnDKRn0TMrkktCVdJk19lvdsu5TwGKzvjIUQfvOfYo-xJU/s4794/Figure-4%20Lead%20II-P%20waves-colored%20(1-2.21-2024)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="716" data-original-width="4794" height="60" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhOwVfEcle9sYzP3cBHQP7FWaleRtbh9fnGh_QeBqf3c9KQAVly2Uc0QeT7zGuQf0pJ5kvC3pUjYg9Pog_pleS7aRc-fjDdWdORBjzW5kNEI9BBVpYXlewTTV7aI6n-IQRI6zWYCpWxdsh0DFnDKRn0TMrkktCVdJk19lvdsu5TwGKzvjIUQfvOfYo-xJU/w400-h60/Figure-4%20Lead%20II-P%20waves-colored%20(1-2.21-2024)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: left;"><u>Figure-4:</u></b><span style="font-family: arial; text-align: left;"> I've colored the P waves from <u>Figure-3</u> (<i>See text</i>).</span></span></td></tr></tbody></table><span style="font-size: medium;"><br /><span style="font-family: arial;"><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">S</span>UMMARY<span style="color: red;">:</span></u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium; text-align: left;">The rhythm in today's case is <b>sinus (</b>ie, <i>regularly-occurring P waves</i><b>)</b> — with <b>2nd-degree AV block, Mobitz Type I (</b><i> = AV Wenckebach</i><b>)</b>. Each of the 3-beat Wenckebach groups begins with a slightly accelerated junctional beat <b>(</b><i>which results in transient AV dissociation</i><b>)</b>.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium; text-align: left;">The overall ventricular rate in today's tracing should be sufficient at ~60-80/minute for adequate perfusion. </span></li><li><span style="font-family: arial; font-size: medium; text-align: left;">Although it is common for Mobitz I to be associated with acute inferior MI — the 12-lead ECG in today's case does <i><u>not</u></i> suggest any acute ST-T wave changes.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;">======================<o:p></o:p></span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">L</span></u></b><b><u><span style="color: #050505;">ADDERGRAM</span></u></b><b><u><span style="color: red;">:</span></u></b><span style="color: #050505;"><o:p></o:p></span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;">To clarify the mechanism for today’s rhythm — I've derived a laddergram with <b><i>step-by-step</i></b> description of events. I begin with <b><u>Figure-5</u></b>.<o:p></o:p></span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: #050505;">NOTE:</span></u></b><span style="color: #050505;"> For review of the Basics for <i>HOW</i> to read (<i>and draw</i>) <b>laddergrams </b>—<b> </b><i>See</i> <b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a>)</b>. </span></span></li></ul><p></p></span></div><div><span style="font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgt8NEvdNqP6MXNHr3wSrAcpRNzVLr4_IIpf0554ct1vF_7CNyngjYeWgBSq4Mcw_-DJ7mXxdSaTp3DeTcuegrS2hPUCuBUk9_35vonmldNfucRTZjZjyNBomnEGk6Tnjvd0gUmDHjB8E-aAT-tVdnL_8LPA6zO4PtPqagbweWqo3M-J5NAtXYTjjw341Q/s3720/Figure-4%20%20Ladder-1%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1520" data-original-width="3720" height="164" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgt8NEvdNqP6MXNHr3wSrAcpRNzVLr4_IIpf0554ct1vF_7CNyngjYeWgBSq4Mcw_-DJ7mXxdSaTp3DeTcuegrS2hPUCuBUk9_35vonmldNfucRTZjZjyNBomnEGk6Tnjvd0gUmDHjB8E-aAT-tVdnL_8LPA6zO4PtPqagbweWqo3M-J5NAtXYTjjw341Q/w400-h164/Figure-4%20%20Ladder-1%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-5:</u></b><span style="text-align: left;"> </span></span><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">The 1st step in laddergram construction — is to represent each of the P waves in the </span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><i>Atrial</i></b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> </span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">Tier</b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">. Since conduction through the atria is fast — </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">vertical</i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> lines are used, drawn from each of the </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">ARROWS</i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> that overlie P waves in this tracing.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9OS9nZQ_ntrpeiaNnPrClgNwAyfu6BanD0A2z8OTY3yRz5-xcYq_nrUNeMGPM7J7S49Nka67My-A_7RL9O9V5-BzACqMVfP4vMhosheGzWCzwpGlk8GUpcbCq1uoQjS144SZWF-4oj-jX4rrkux2cL0HVcKeUUhb7f8gZOJbnL3pEMGSl8G5MCnxie44/s3712/Figure-5%20%20Ladder-2%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1596" data-original-width="3712" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj9OS9nZQ_ntrpeiaNnPrClgNwAyfu6BanD0A2z8OTY3yRz5-xcYq_nrUNeMGPM7J7S49Nka67My-A_7RL9O9V5-BzACqMVfP4vMhosheGzWCzwpGlk8GUpcbCq1uoQjS144SZWF-4oj-jX4rrkux2cL0HVcKeUUhb7f8gZOJbnL3pEMGSl8G5MCnxie44/w400-h173/Figure-5%20%20Ladder-2%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-6:</u></b><span style="text-align: left;"> </span></span><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">Since all QRS complexes are narrow — </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><u>each</u></i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> of the 12 beats in this tracing is supraventricular. Knowing this allows me to draw in conduction within the </span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><i>Ventricular</i></b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> </span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">Tier</b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> — which I represent with slightly inclined </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">forward-directed</i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> lines with an arrow to indicate the downward direction of conduction. <br /></span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><u>NOTE:</u></b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> I find </span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><i>Power</i></b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> </span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">Point</b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> optimal for drawing laddergrams — as it allows ready duplication of laddergram elements </span><u style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">and</u><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> precisely vertical displacement to ensure laddergram elements appear </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><u>exactly</u></i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> below P waves and QRS complexes in the original rhythm strip.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZ2k9YXYhyphenhyphenL64sldEJ7jODsjwPAyrzZ88SeEOuTw28dvextQUD0MwvYfBF9w5WV-doBi_uKjpMXZzYesDme9PuRidGGxroibgEGraQZ94AU0dgnmwOpSwrTepgII2V0CJlfgm5MIkniQIdgEmLRRAolJKSw4gKSjYMTz5MpsyboxAOwnqknLcNWoypU2E/s3708/Figure-6%20%20Ladder-3%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1596" data-original-width="3708" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZ2k9YXYhyphenhyphenL64sldEJ7jODsjwPAyrzZ88SeEOuTw28dvextQUD0MwvYfBF9w5WV-doBi_uKjpMXZzYesDme9PuRidGGxroibgEGraQZ94AU0dgnmwOpSwrTepgII2V0CJlfgm5MIkniQIdgEmLRRAolJKSw4gKSjYMTz5MpsyboxAOwnqknLcNWoypU2E/w400-h173/Figure-6%20%20Ladder-3%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-7:</u></b><span style="text-align: left;"> </span></span><span style="color: #050505; font-family: arial; text-align: justify;">It's now time to <b><i>"solve"</i></b> the laddergram. I begin by a survey of all P waves (<i>RED arrows — which are represented by the RED vertical lines in the Atrial Tier</i>) — and of all 12 QRS complexes (<i>vertical RED lines within the Ventricular Tier</i>) — with the goal of determining which P waves seem <i>most</i> likely to conduct to the ventricles.<br /></span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNX_k7360YlRo_QiMQH8_Rc4x8JT4RwkENHpGlK7Nmf0EsjS2eNEVqXYRo8VoQrn7lyqo_8xegMQ-ZL4e1gAvWghnEyEzMlDa3z_nR_uOgk1U0U-IcjzdEDEa2zd86HYwhraZaFqf-wmpqMm_eXXTP6fz_fXT87mUsAOjdY99NKs-couEHUXI15aJ32JY/s3712/Figure-7%20%20Ladder-4%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1598" data-original-width="3712" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNX_k7360YlRo_QiMQH8_Rc4x8JT4RwkENHpGlK7Nmf0EsjS2eNEVqXYRo8VoQrn7lyqo_8xegMQ-ZL4e1gAvWghnEyEzMlDa3z_nR_uOgk1U0U-IcjzdEDEa2zd86HYwhraZaFqf-wmpqMm_eXXTP6fz_fXT87mUsAOjdY99NKs-couEHUXI15aJ32JY/w400-h173/Figure-7%20%20Ladder-4%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-8:</u></b><span style="text-align: left;"> "Armed" with the clue that the PR intervals preceding beats #3,6,9 and 12 look to be both normal and equal — I felt comfortable presuming that each of these <i>BLUE-arrow</i> P waves are conducting <b>(</b><i>which I illustrate with the slanted BLUE lines within the AV Nodal Tier that connect these P waves to the appropriate QRS complexes. </i></span></span><br /></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2xh3dBt_hYwyN3uegUGzrj_PjfTSscoBtySwOpG6lXbtz8PKKDK4U512olRsmMRqR65UC0xIO7IIz9091Tbpx5GPbvaw4uFy4PuWxi_V-SGeTMY_4weEwjtCDh2Abt-D2igNMAiI9KT98Wn86p9BLUBa225734smDGKY6OuXuRJDvlrVNiJDrg1aarcM/s3718/Figure-8%20%20Ladder-5%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1594" data-original-width="3718" height="171" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh2xh3dBt_hYwyN3uegUGzrj_PjfTSscoBtySwOpG6lXbtz8PKKDK4U512olRsmMRqR65UC0xIO7IIz9091Tbpx5GPbvaw4uFy4PuWxi_V-SGeTMY_4weEwjtCDh2Abt-D2igNMAiI9KT98Wn86p9BLUBa225734smDGKY6OuXuRJDvlrVNiJDrg1aarcM/w400-h171/Figure-8%20%20Ladder-5%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-9:</u></b><span style="text-align: left;"> </span></span><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">I then connected the 2nd P wave in each group <b>(</b><i>highlighted by the dark BLUE arrows</i><b>)</b> — with the appropriate QRS complexes for beats #4,7 and 10</span><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> in the </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">Ventricular</i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> Tier <b>(</b><i>slanted dark </i></span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">BLUE lines within the AV Nodal Tier</i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><b>)</b>. Note slight increase in the amount of <u style="font-style: italic;">slanting</u> of these <i>dark BLUE lines, </i>reflecting slight increase in the PR interval since the <i>light BLUE P waves </i>conducted beats #3,6,9 and 12.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjlVRlCHih37lZ0KRN5MuvNUaTqHjQEtBu7qhRabFIba-lZetv9QZNTGO0NZNnJ3c-xoKWLVehRT5_Od5Ydr00xkEjCY_43t8Tb0BvZ9YNtfkF2e5KD_pd7Xaz8xK-59S7wi7XwomBuGn5lTtHfUw0IPIy2rrFqth3RUAFw4O6E84c-llrR_hZB-TuK3z8/s3714/Figure-9%20%20Ladder-6%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1604" data-original-width="3714" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjlVRlCHih37lZ0KRN5MuvNUaTqHjQEtBu7qhRabFIba-lZetv9QZNTGO0NZNnJ3c-xoKWLVehRT5_Od5Ydr00xkEjCY_43t8Tb0BvZ9YNtfkF2e5KD_pd7Xaz8xK-59S7wi7XwomBuGn5lTtHfUw0IPIy2rrFqth3RUAFw4O6E84c-llrR_hZB-TuK3z8/w400-h173/Figure-9%20%20Ladder-6%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-10:</u></b><span style="text-align: left;"> </span></span><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">I next chose to represent the </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">YELLOW</i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> <i>arrow</i> P waves — which clearly are </span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><u>not</u></i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> conducting because they are <i><u>not</u></i> followed by any QRS complexes <b>(</b></span><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">YELLOW butt ends drawn within the AV Nodal Tier</i><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><b>)</b>. </span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"><i>This left a limited number of P waves and QRS complexes unaccounted for ...</i></b></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKDjWnGQ6qBBjOHUW4TMWph8XDD7iWH5j-ht-5PM6NGShLwm3wHRTJJpZtgdP-w5B9araa2DugcA5GOAbgC7uPl1B9wbKzrv8tpPEa3oHEFvzyWNPE1IPoaeRAOIDobWn-700-bYDCCW6ASAsL5hwALPgwjVTFt1e0_0OmLwuqHDBrXuMiAXsC40z-bUo/s3712/Figure-10%20%20Ladder-7%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1600" data-original-width="3712" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgKDjWnGQ6qBBjOHUW4TMWph8XDD7iWH5j-ht-5PM6NGShLwm3wHRTJJpZtgdP-w5B9araa2DugcA5GOAbgC7uPl1B9wbKzrv8tpPEa3oHEFvzyWNPE1IPoaeRAOIDobWn-700-bYDCCW6ASAsL5hwALPgwjVTFt1e0_0OmLwuqHDBrXuMiAXsC40z-bUo/w400-h173/Figure-10%20%20Ladder-7%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: left;"><u>Figure-11:</u></b><span style="text-align: left;"> But the PR interval for the <i>WHITE arrow</i> P waves is clearly <i>too short</i> to conduct! <b>(</b><i>represented by WHITE butt ends drawn within the AV Nodal Tier</i><b>)</b>.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjz_DMz5dmM-HT8VEYkXlz4kuQ3tWzoZvta6cVDylWKRXwbLdqgNzpmPEQmx6P2j9anOK3sjDUj8tAj71xyA38DQRR3tV51XMxsBv1GUmU45y37s1aLqp4uQ5u8T7_qOpaD7GAU1F6tvwKEvUJImRMUTrU2haLawM1h3JlDrmJvwmidvQfDaUNbmxZp568/s3716/Figure-11%20%20Ladder-8%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1600" data-original-width="3716" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjz_DMz5dmM-HT8VEYkXlz4kuQ3tWzoZvta6cVDylWKRXwbLdqgNzpmPEQmx6P2j9anOK3sjDUj8tAj71xyA38DQRR3tV51XMxsBv1GUmU45y37s1aLqp4uQ5u8T7_qOpaD7GAU1F6tvwKEvUJImRMUTrU2haLawM1h3JlDrmJvwmidvQfDaUNbmxZp568/w400-h173/Figure-11%20%20Ladder-8%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: left;"><u>Figure-12:</u></b><span style="text-align: left;"> Since neither the <i>YELLOW </i>nor <i>WHITE arrow</i> P waves are conducting — <b>beats #2,5,8 and 11 <i><u>have</u> to be</i> arising from the AV node! (</b><i>The dotted RED lines with butt ends indicate retrograde conduction from the slightly accelerated junctional escape beats — that prevent WHITE arrow P waves from being conducted through the AV Nodal Tier</i><b>)</b>.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEaKcSvc2CrCrCbEtGSOOYOKBWeSmAsHcmeMdJAh72ucojlOW4EBUtVTj7p3NuY8uaEkB-1f7I55NkZelucZA_oYv200TMUd3U6_68_FB_DE4nYHXqb360NmFpRt02P3jp6FZqidEAceR8IoMTXtoyfzVJ8hWdRdLeQH9FfLoc8XgXh51YtpvK3c3k3SE/s3716/Figure-12%20%20Ladder-1-9%20(12-30.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1604" data-original-width="3716" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiEaKcSvc2CrCrCbEtGSOOYOKBWeSmAsHcmeMdJAh72ucojlOW4EBUtVTj7p3NuY8uaEkB-1f7I55NkZelucZA_oYv200TMUd3U6_68_FB_DE4nYHXqb360NmFpRt02P3jp6FZqidEAceR8IoMTXtoyfzVJ8hWdRdLeQH9FfLoc8XgXh51YtpvK3c3k3SE/w400-h173/Figure-12%20%20Ladder-1-9%20(12-30.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-13:</u></b><span style="text-align: left;"> </span></span><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">My completed laddergram illustrating the mechanism for today's rhythm. There is</span><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> </span><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">2nd-Degree AV Block, Mobitz Type I (</b><i style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">AV Wenckebach</i><b style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;">)</b><span style="caret-color: rgb(5, 5, 5); color: #050505; font-family: arial; text-align: justify;"> — in which slightly accelerated junctional escape beats produce 1 beat of AV dissociation until sinus conduction resumes with beats #3,6,9 and 12.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><br /></div><div style="text-align: left;"><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><span><b><u>Final <i>Advanced</i><i> </i>Point:</u> </b></span></span></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;">Did <i>YOU</i> notice in <u>Figure-13</u> — that <b>the QRS of each of the junctional beats (</b> <i>= beats #2,5,8 and 11</i><b>) is slightly <u style="font-style: italic;">taller</u> than the QRS of the remaining 8 beats on this tracing?</b></span></span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">The above subtle observation can sometimes be a very helpful clue that these slightly <i>different-looking</i> beats are </span><u style="font-family: arial; font-style: italic; text-align: left;">not</u><span style="font-family: arial; text-align: left;"> sinus-conducted — but instead arise from the AV Node.</span></span></li><li><span style="font-family: arial; font-size: medium; text-align: left;">The reason escape beats from the AV Node sometimes look slightly different than sinus-conducted beats — is that the precise site of origin within the AV Node from where these beats arise may be slightly different than the path within the AV Node through which sinus-conducted beats pass.</span></li><li><span style="font-family: arial; font-size: medium; text-align: left;"><b><u>To Emphasize:</u></b> This clue is <u style="font-style: italic;">not</u> needed for us to know that beats #2,5,8,11 in today's tracing are junctional beats — since it is obvious that the P waves preceding beats #2,5,8,11 are too close to the QRS to be conducted. But there <u style="font-style: italic;">are</u> times when it will not be readily apparent if a given QRS complex represents a sinus-conducted beat <u style="font-style: italic;">vs</u> junctional escape — in which case, the observation that QRS morphology differs slight may reveal which beats are junctional escape beats <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2013/03/ecg-interpretation-review-63-av-block.html" target="_blank">ECG Blog #63</a></b> <i>— for a clinical example of this phenomenon!</i><b>)</b>.</span></li></ul></div></div><div><br /></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==========================================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to</span><span> </span></span><span face="system-ui, -apple-system, BlinkMacSystemFont, ".SFNSText-Regular", sans-serif" style="caret-color: rgb(5, 5, 5); color: #050505; text-align: left;">ไกรสร เต็ง</span><span style="caret-color: rgb(5, 5, 5); color: #050505;"> (</span><i style="caret-color: rgb(5, 5, 5); color: #050505;">from Bangkok, Thailand</i><span style="caret-color: rgb(5, 5, 5); color: #050505;">) for the case and this tracing.</span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==========================================</span></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><div class="separator" style="clear: both; text-align: justify;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"></a></span></div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></span><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></p></div><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==============================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><ul><li style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a> </b>— Reviews my System for <b><i>Rhythm</i></b> <b>Interpretation</b>, </span></span></span><span style="font-family: arial;"><span>using th</span></span><span style="font-family: arial;">e </span><b><span style="color: red;">P</span>s, <span style="color: red;">Q</span>s & 3<span style="color: red;">R</span> Approach</b><span style="font-family: arial;">.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a></b> — Reviews my System for <b>12-Lead ECG Interpretation</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/08/ecg-blog-245-59-heart-failure-and-acute.html" target="_blank">ECG Blog #245</a></b> — Reviews ECG diagnosis of <b>LVH</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> draw <b><span style="color: red;">L</span>addergrams </b></span><span><b>(</b><i>w</i></span><i>ith LINKS to more than 90 laddergram cases — many with step-by-step sequential illustration</i><b>)</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" target="_blank">ECG Blog #192</a></b> — The <b>3 <i><u>Causes</u></i></b> of <b>AV Dissociation</b>.</li></ul><div style="text-align: justify;"><div><span style="text-align: left;"><span><div style="text-align: justify;"><ul><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-191-ecg-mp-8-is-av-block.html" target="_blank">ECG Blog #191</a></b> — Reviews the difference between <b>AV Dissociation</b> <u>vs</u> <b><i>Complete</i> AV Block</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2023/08/ecg-blog-389-quote-from-sherlock-holmes.html" target="_blank">ECG Blog #389</a></b> — <b><a href="https://ecg-interpretation.blogspot.com/2023/04/ecg-blog-373-86yo-and-this-rhythm.html" target="_blank">ECG Blog #373</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-344-mobitz-i-mobitz-ii-or.html" target="_blank">ECG Blog #344</a></b> — for review of some cases that illustrate <b><i>"AV block problem-solving"</i></b>.</span></li><li style="text-align: justify;"><span><br /></span></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2013/03/ecg-interpretation-review-63-av-block.html" target="_blank">ECG Blog #63</a> </b>— Reviews a case of <b>2nd-Degree AV Block, Mobitz Type I</b> with <b>Junctional <i>Escape</i> Beats.</b></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-267-75-group-beating-and.html" target="_blank">ECG Blog #267</a></b> — Shows <b><i>step-by-step</i></b> <b><u>Laddergrams</u></b>, with derivation of a case of Mobitz I with more than a single possible explanation.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2023/11/ecg-video-blog-404-344-mobitz-i-mobitz.html" target="_blank">ECG Blog #404</a> (</b><i>ECG <u>Video</u></i><b>)</b> — applies the Ps,Qs,3R Approach to a case of <b>2nd-degree AV Block (</b> = <i>Mobitz I <u>or</u> Mobitz II <u>or</u> Neither</i><b>)</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2023/11/ecg-blog-405-is-av-block-complete-vs-av.html" target="_blank">ECG Blog #405</a> (</b><i>ECG <u>Video</u></i><b>)</b> — applies the Ps,Qs,3R Approach to a case of <b>AV Dissociation</b> <u><i>vs</i></u> <b>Complete AV Block (</b><i>What's the difference?</i><b>)</b>.</li></ul><div><br /></div></div></span></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"></div><span style="font-family: arial;"> <br /><div style="text-align: justify;"><div style="text-align: left;"><span style="font-family: arial;"><div style="text-align: justify;"><b><u><span face="Arial, sans-serif" style="color: red;">A</span></u></b><span face="Arial, sans-serif"><b style="text-decoration: underline;">DDENDUM</b><b> </b><b style="text-decoration: underline;"><span style="color: red;">(</span></b><i>1/6/2024</i><b><span style="color: red;">)</span>:</b></span></div><div style="text-align: justify;"><span face="Arial, sans-serif"><b><br /></b></span></div></span></div><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; text-align: left;"></span></p><div><div style="text-align: center;"><span style="font-family: arial;"><br /></span></div><div style="text-align: center;"><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM6IE0axC-_2vJMD4d9lTnIIy2zqJZkybwADlcZyqs9SldX9AUMWa62snq9l2lgm14vb-Gtc47amXBkyV69cZd9C7oNg2BCBeRl64i1sHZm2e3DCYB5fs4bv04vDojyI5H7FabD9EOiu0/s2222/ECG-MP-52+-+2nd+Degree+AV+Blocks+%25286-24.1-2021%2529.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="462" data-original-width="2222" height="84" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM6IE0axC-_2vJMD4d9lTnIIy2zqJZkybwADlcZyqs9SldX9AUMWa62snq9l2lgm14vb-Gtc47amXBkyV69cZd9C7oNg2BCBeRl64i1sHZm2e3DCYB5fs4bv04vDojyI5H7FabD9EOiu0/w400-h84/ECG-MP-52+-+2nd+Degree+AV+Blocks+%25286-24.1-2021%2529.png" width="400" /></a></div></div><div style="text-align: center;"><span style="font-family: arial;"><br /></span></div><div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dyVTwP3nAUNXa-XeLIzC_lt3utxLxWpbzpab2ytUreaZkm09za5O0sf3m9rfsIvBMU31WPMXogSvTCE9-fUdA' class='b-hbp-video b-uploaded' frameborder='0'></iframe></span></div><span style="font-family: arial;"><div style="text-align: justify;"><span>This <b>15</b>-minute <b>ECG Video (<span style="color: red;">M</span>edia <span style="color: red;">P</span>EARL <span style="color: red;">#</span>52)</b> — Reviews the <b>3 Types</b> of <b>2nd-Degree AV Block</b> — <u>plus</u> — the <i>hard-to-define</i> term of <b><i>"high-grade"</i></b> <b>AV block</b>. I supplement this material with the following 2 PDF handouts.</span></div><div style="text-align: justify;"><span><br /></span></div><div style="text-align: justify;"><span><br /></span></div><div style="text-align: justify;"><span><br /></span></div><div style="text-align: justify;"><span><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: -webkit-standard; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><div class="separator" style="clear: both;"><a href="https://dl.dropboxusercontent.com/s/p5o4fsrvt6mzqv3/z-ECG%20Audio%20Pearl-4%20%282-12.1-2021%29-USE-Faster.m4a?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1470" data-original-width="2048" height="288" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUAcJgawC2j9KDwKlACfTSKiiFHIo_a9sS0f1ZnbphiPfeBWj2mSS913KvLr_WX6iCOOpF-G8Bprw20u8pN73MMgyBaMr4Q21EXsDMgYLbRZSWW-bKbUSMQjiEFEj72JNPtxlA1iLfHe8/w400-h288/MP-4+%2528186%2529-Suspect+Mobitz+I-USE.png" width="400" /></span> —</a></div><br /></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial;"><span><b style="text-align: justify;"><u><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span><span>4</span></u></b><b style="text-align: justify;"> (</b><i><span style="text-align: justify;">4:3</span><span style="text-align: justify;">0</span></i><i style="text-align: justify;"> minutes <b><u>Audio</u></b></i><b style="text-align: justify;">)<span style="color: red;">:</span></b></span><span style="text-align: justify;"><span> — takes a brief look at the <b>AV Blocks</b> — and focuses on <i>WHEN</i> to <i>suspect</i> <b>Mobitz I</b>.</span><br /><br /></span></span></td></tr></tbody></table><span style="font-family: arial; text-align: left;"></span></span></div><div style="text-align: justify;"><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://www.dropbox.com/s/v01yvlqafd5c6z2/AV%20Blocks-Pg%2060-66%20ECG-PB%20%281-16.22-2021%29-USE.pdf?dl=0" target="_blank">Section 2F</a> (</b><i>6 pages = the <b>"<u>short</u>" Answer</b></i><b>)</b> from my ECG-2014 Pocket Brain book provides quick written review of the <b>AV Blocks</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><span><b><a href="https://www.dropbox.com/s/k1jk1y4o4uu48ab/20.0-%20ACLS-2013-e-PUB-AV%20Block-Dissociaton-%2810-15.11-2014%29-LOCK.pdf?dl=0" target="_blank">Section 20</a></b> </span><b>(</b><i>54</i><i> pages = the <b>"<u>long</u>" Answer</b></i><b>)</b> from my ACLS-2013-Arrhythmias <i>Expanded</i> Version provides <i>detailed</i> discussion of <i>WHAT</i> th</span>e <b>AV Blocks</b> are — and what they are <u>not</u>!</li></ul></div></span></div></div></div></div></span></div></div></div></div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropbox.com/s/asovnn9agpistkq/z-ECG-Audio%20Pearl-75%20Junctional%20Rhythm%20%2812-5.1-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1692" data-original-width="3516" height="193" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWuXRDxEkAjeiDUrBaQUT0ffo4or7MGqSwxa3-yPAf6FkXrQkrTI2hSrqbkTh2ck2WElNuY-wGbogEG2aeeD2se1w8hPWl5_254LO9uVK6nA3gGQ_-DpUCH85oZSHA6vgX8SueRR49rpg/w400-h193/ECG-MP-75+Appropriate+Junction+%252812-4.21-2021%2529-USE.png" width="400" /></span> —</a><i style="text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></i></span></div><p></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>75 (</b><i>6:10 minutes <b><u>Audio</u></b></i><b>)</b> — Reviews how to tell <u>IF</u> a <b><span>J</span>unctional (</b><i>AV Nodal</i><b>) <span>R</span>hythm is <span>p</span>athologic <u>or</u> <span>a</span>ppropriate<span>?</span></b></span></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjatWee2W48Bh23rkm3hVBpifsDfzqpN9-OjTIK4ekm14sEl2MRlkvCkOxtxMNVMFYAt07m0SNZmzaKDLeUpP0X8gXcl-Am4RJswxdfdywyAAFRHLkBvJu5KXkpl7ix9y9FKiUluxqsrY/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjatWee2W48Bh23rkm3hVBpifsDfzqpN9-OjTIK4ekm14sEl2MRlkvCkOxtxMNVMFYAt07m0SNZmzaKDLeUpP0X8gXcl-Am4RJswxdfdywyAAFRHLkBvJu5KXkpl7ix9y9FKiUluxqsrY/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: justify;"><br /></div><div class="separator" style="clear: both; text-align: justify;"><p style="text-align: left;"></p><p class="MsoNormal" style="margin: 0in; text-align: right;"><br /></p></div></div></div></span></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-50609831831724265792023-12-30T00:10:00.000-05:002023-12-30T00:10:39.677-05:00ECG Blog #410 — How Tall are the T Waves?<span style="font-family: arial; font-size: medium;"><br /></span><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>QUESTION:</u></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><i>HOW would YOU interpret</i> the ECG in <u style="font-weight: bold;">Figure-1</u> — if no clinical information was provided? </span></li></ul></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjaykO7VlzDEGXo8CO_3wP6hanb5cSBhzmfoFEH0lprfmqTvcVhzpQ9-x_ercFxRbe0vhoz5qKhl8_KrPM9ytIKQNqKdnn2JCS_fg_sDK3v7lj9xXGM2EMJ0Oq-jdmR1yKTs9-kiNKjuuSqMmc0jm3dgVcevahP9IMbnGnwbySvaYyxVM4bc8mgZsgpaVk/s3634/Figure-1%20%20ECG-1%20Shark%20Fin%20(10-27.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2790" data-original-width="3634" height="308" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjaykO7VlzDEGXo8CO_3wP6hanb5cSBhzmfoFEH0lprfmqTvcVhzpQ9-x_ercFxRbe0vhoz5qKhl8_KrPM9ytIKQNqKdnn2JCS_fg_sDK3v7lj9xXGM2EMJ0Oq-jdmR1yKTs9-kiNKjuuSqMmc0jm3dgVcevahP9IMbnGnwbySvaYyxVM4bc8mgZsgpaVk/w400-h308/Figure-1%20%20ECG-1%20Shark%20Fin%20(10-27.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial; text-align: start; text-decoration: underline;"><b>Figure-1:</b></span><span style="font-family: arial; text-align: start;"> The initial ECG in today's case.<span style="text-align: center;"><span style="text-align: start;"> </span></span><b style="text-align: center;">(</b><i style="text-align: center;">To improve visualization — I've digitized the original ECG using</i><span style="text-align: center;"> </span><b style="text-align: center;"><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span style="text-align: center;">.</span></span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span>==================================</span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><u>The <span style="color: red;">H</span>ISTORY in <i><span style="color: red;">T</span>oday's</i> <span style="color: red;">C</span>ASE:</u></b></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span>The patient in today's case is a teenager who presented to the ED (<i><u>E</u>mergency <u>D</u>epartment</i>) in <b><i>cardiac</i></b> <b>arrest</b> after <b>electrocution</b>. The ECG in <u>Figure-1</u> — was obtained following successful resuscitation.</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">The "good news" — is that after an extended hospitalization, the patient was finally discharged home, and doing well.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">==================================</span></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>A <i><span style="color: red;">C</span>loser</i> <span style="color: red;">L</span>ook at <i>Today's</i> ECG:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">The rhythm in <u>Figure-1</u> is <b><i>sinus</i></b> — with regular upright P waves with a constant and normal PR interval in lead II.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">At 1st glance of the chest leads — the QRS complex appears to be significantly widened. However, on looking closer at leads V1 and V6 — and especially at the QRS in the limb leads — it becomes apparent that the QRS is probably of normal duration!</span></li><li><span style="font-family: arial; font-size: medium;">But — IF the QRS is <i>not</i> prolonged — this means that we are looking at perhaps <b>the <i>greatest</i> amount of ST segment elevation</b> in <b>lead V3</b> that I <b>(</b><i>and perhaps you</i><b>) have <i>ever</i> seen! (</b><i>that attains <u>more</u> than 40 mm in lead V4</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">As discussed in <b><a href="https://ecg-interpretation.blogspot.com/2023/02/ecg-blog-364-vt-in-need-of-cardioversion.html" target="_blank">ECG Blog #364</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-265-73-vt-or-something-else.html" target="_blank">ECG Blog #265</a></b> — We are looking at <b><i>"<u>Shark</u> <u>Fin</u>"</i></b> <b>ST elevation!</b></span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><div style="font-family: -webkit-standard;"><span style="text-decoration: underline;"><b><span style="font-family: arial; font-size: medium;"><i><span style="color: red;">S</span>hark <span style="color: red;">F</span>in</i> <span>M</span>orphology</span></b></span></div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;">It's important to be aware of the pattern of <b><i>"Shark Fin"</i></b> <b>ST segment elevation</b> — in which the QRS complex looks wide, because it <i><u>blends</u></i> <u>in</u> with ST segments that show <i>extreme</i> S</span><span style="font-family: arial;">T elevation in multiple leads. As a result — the boundary between the end of the QRS complex and the beginning of the ST segment becomes indistinguishable in those leads showing marked ST elevation or depression.</span></div><div><ul style="font-family: -webkit-standard;"><li><span style="font-family: arial; font-size: medium;"><i>"Shark Fin"</i> ST segment elevation is most often a sign of severe <b><i>transmural</i></b> <b>ischemia</b> that results from <b><i>acute</i> coronary occlusion</b>. Today's case is different in that <b>profound <i>myocardial</i> injury (</b><i>from electrocution</i><b>)</b> rather tha</span><span style="font-family: arial;">n acute coronary occlusion is the cause of this ECG pattern.</span></li><li><br /></li><li><span style="font-family: arial; font-size: medium;"><b><u>PEARL:</u></b> The <i>KEY</i> for confirming that "Shark Fin" morphology is the cause of the striking ECG picture in <u>Figure-1</u> — is to find 1 or 2 leads in which you can clearly define the limits <b>(</b><i><u>end</u> point</i><b>)</b> of the QRS complex. The most helpful leads for clarifying the end point of the QRS in today's case are <b>lead V1 </b>and<b> lead V6</b>. </span></li><li><span style="font-family: arial; font-size: medium;">Note in <b><u>Figure-2</u></b> </span><span style="font-family: arial;">— that I've drawn in a </span><b style="font-family: arial;"><i>RED</i> line </b><span style="font-family: arial; text-decoration: underline;"><b><i>parallel</i></b></span><b style="font-family: arial;"> to the heavy ECG grid line</b><span style="font-family: arial;"> in the </span><i style="font-family: arial;">simultaneously-recorded</i><span style="font-family: arial;"> chest leads. By choosing the end point of the QRS that is clearly visible in leads V1 and V6 — I'm able to define the end point of the QRS complex in the other chest leads ( <i>= leads V2-thru-V5</i>), knowing that the ST segment begins just to the right of this <i>vertical RED line</i></span><span style="font-family: arial;">.</span></li></ul><div><br /></div></div></span></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjLSp1Ke9sZBY9a6AgOSawvu-A2gcHFsjaLkGeEMTM1f2tiBX9XREgnzjvwa-AzLQQ1hF18WXIvyZtRaq-l6q8sO1kOWnLZMzGJ56W4i0twju_oTdyTb3m0zWLcRuKzVT4id-RLftgrpUI_inZzAQwLYIwIm0LChcWE29fR3cl9QNZofNUu-RO8zBQ52XQ/s3624/Figure-2%20%20ECG-1%20Shark%20Fin-RED%20(10-27.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2790" data-original-width="3624" height="308" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjLSp1Ke9sZBY9a6AgOSawvu-A2gcHFsjaLkGeEMTM1f2tiBX9XREgnzjvwa-AzLQQ1hF18WXIvyZtRaq-l6q8sO1kOWnLZMzGJ56W4i0twju_oTdyTb3m0zWLcRuKzVT4id-RLftgrpUI_inZzAQwLYIwIm0LChcWE29fR3cl9QNZofNUu-RO8zBQ52XQ/w400-h308/Figure-2%20%20ECG-1%20Shark%20Fin-RED%20(10-27.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial; text-align: start; text-decoration: underline;"><b>Figure-2:</b></span><span style="font-family: arial; text-align: start;"> I've drawn a <b><i>vertical</i> timeline <i>downward</i></b> from the end point of the QRS complex in <b>lead V1</b> — so as to define the <i>beginning</i> of the ST segment in the other chest leads. Note that this vertical <i>RED line</i> passes through the clearly defined end point of the QRS complex in <b>lead V6 (</b><i>See text</i><b>)</b>.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>BOTTOM Line in <i>Today's</i> CASE:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Since the <i>vertical RED line</i> in <u>Figure-2</u> marks the end of the QRS complex in each of the 6 chest leads — everything to the right of this <i>RED line</i> represents the markedly elevated <i><b>"shark fin"</b></i> <b>shape</b> of <b>ST elevation</b>.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Alternatively — the shape of the ST elevation in lead V2 might also be consistent with a component of <b><i>Brugada</i></b> <b>Phenocopy (</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2021/07/ecg-blog-238-53-what-is-phenocopy.html" target="_blank">ECG Blog #238</a>)</b>. That said, even if true — ST elevation in the remaining chest leads is still virtually certain to represent <i>"shark fin"</i> ST elevation from severe myocardial injury.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==========================================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to </span><span>Hamdallah Naser</span><span> (</span><i>from AL-Najaf, Iraq</i><span>) for the case and this tracing.</span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==========================================</span></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><div class="separator" style="clear: both; text-align: justify;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"></a></span></div><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhrVnpRQ5bqMIaY3aP00aunkB63LpUVxDGS1XT8Jx_SjrY9Mfm6jO3_13kLwEtSbq2l6FcOoERQTFsVhMNMKXwxZhspcRUVEYvfulqaKhbDZ7XsXzut1Wqv6ttWBZCJOMkz3kWVnZBV2Ng/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></span><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">=====================================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">A</span></u></b><b><u><span style="color: #050505;">DDENDUM</span></u></b><b><span style="color: #050505;"> </span></b><b><span style="color: red;">(</span></b><i><span style="color: #050505;">12/30/2023</span></i><b><span style="color: red;">)</span></b><b><span style="color: #050505;">:</span></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><span><span style="color: #050505;">The <b><i><u>Audio</u></i></b> <b>Pearl</b> below reviews the concept of <i>"shark fin" </i>ST elevation.</span></span> </span></li></ul></div></div><div><span style="font-family: arial; font-size: medium;"><span style="color: #050505; text-align: left;"></span></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropboxusercontent.com/s/pkwzpihljdw53jy/z-ECG-Audio%20Pearl-73%20Shark%20Fin%20%2811-26.2-2021%29-1.3%20FASTER.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1092" data-original-width="2048" height="214" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4yrEZpmhAZEjCQtUgxruCoIcxN7jZX37TbWjpvH3ooq2XHqh-LfRv2yJP6e1kqfBMEdt-gBL4CIA7BRXc4NFxd6vMRqzbgoLTurg2Rgasg02MsO2UF1ne0Hz7upio2voAxw2wbCUdhVE/w400-h214/ECG-MP-73+Shark+Fin+ST+Elevation+%25289-26.1-2021%2529-USE.png" width="400" /></span> —</a><span> </span></span></div><p style="text-align: left;"></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>73 (</b><i>5:40 minutes</i> <b><i><u>Audio</u></i>)</b> — Reviews the concept of <b><i>"</i></b><b><i><span>S</span>hark <span>F</span>in"</i></b> <b><span>S</span>T <span>e</span>levation </b>and <b><span>d</span>epression</b> as a sign of extensive acute infarction.</span></p><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;">==============================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b>Additional<i> Relevant</i></b> <b>ECG Blog Posts to Today’s Case:</b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><ul><li style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a> </b>— Reviews my System for <b><i>Rhythm</i></b> <b>Interpretation</b>, using th</span></span><span style="font-family: arial;">e </span><b style="font-family: arial;"><span style="color: red;">P</span>s, <span style="color: red;">Q</span>s & 3<span style="color: red;">R</span> Approach</b><span style="font-family: arial;">.</span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-265-73-vt-or-something-else.html" target="_blank">ECG Blog #265</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2023/02/ecg-blog-364-vt-in-need-of-cardioversion.html" target="_blank">ECG Blog #364</a></b> — Review cases of <b><i>Shark-Fin</i></b> <b>ST Elevation</b>.</span></li></ul><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjatWee2W48Bh23rkm3hVBpifsDfzqpN9-OjTIK4ekm14sEl2MRlkvCkOxtxMNVMFYAt07m0SNZmzaKDLeUpP0X8gXcl-Am4RJswxdfdywyAAFRHLkBvJu5KXkpl7ix9y9FKiUluxqsrY/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjatWee2W48Bh23rkm3hVBpifsDfzqpN9-OjTIK4ekm14sEl2MRlkvCkOxtxMNVMFYAt07m0SNZmzaKDLeUpP0X8gXcl-Am4RJswxdfdywyAAFRHLkBvJu5KXkpl7ix9y9FKiUluxqsrY/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><div><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"></span></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div><br /></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com2tag:blogger.com,1999:blog-3364570834099131201.post-63114648805375774862023-12-23T17:22:00.001-05:002023-12-23T17:22:31.506-05:00ECG Blog #409 — Every-Other-Beat ... <div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></div><div style="text-align: justify;"><span style="text-align: justify;"><span style="font-family: arial; font-size: medium;">The ECG in <u style="font-weight: bold;">Figure-1</u> — was obtained from a patient with palpitations. The patient was hemodynamically stable in association with this rhythm.</span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="text-align: justify;"><b><u><span style="font-family: arial; font-size: medium;">QUESTIONS:</span></u></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><b><i>What is the <u>rhythm</u></i></b> in <u>Figure-1</u>? </span></li><li><span style="font-family: arial; font-size: medium;"><i> — <b>How <u>certain</u></b> are you of your answer? </i></span></li><li><span style="font-family: arial; font-size: medium;"><i><br /></i></span></li><li><span style="font-family: arial; font-size: medium;"><i> — </i><b>Why is QRS morphology </b><i><u><b>changing</b></u></i><b>? </b></span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1fMq8YS6tm5Z1-as9zmIIULbZ4408CENexZAzNQl_iQD444qW9u7OpLEf6rGehxl2LRE9OFRJsqUSsBK-1K4IjJJAY6rJ0866uzHUB3qT9coWg4jn0x5gywyDRDglNg8vXGc6c4z46Ammals3W8DQPJv4GNjJnX-T2Z-R1HGoUYvOHzJ8x5LMG-C_XWk/s3170/Figure-1%20%20ECG-1%20(12-19.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1786" data-original-width="3170" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh1fMq8YS6tm5Z1-as9zmIIULbZ4408CENexZAzNQl_iQD444qW9u7OpLEf6rGehxl2LRE9OFRJsqUSsBK-1K4IjJJAY6rJ0866uzHUB3qT9coWg4jn0x5gywyDRDglNg8vXGc6c4z46Ammals3W8DQPJv4GNjJnX-T2Z-R1HGoUYvOHzJ8x5LMG-C_XWk/w400-h225/Figure-1%20%20ECG-1%20(12-19.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b><u>Figure-1:</u></b><span> The </span><b><i><u>initial</u></i></b><span> </span><b>ECG</b><span> in today's case.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div></div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u><i>My Interpretation</i> of the ECG in Figure-1:</u></b></div><div style="text-align: justify;"><div><span style="font-family: arial; font-size: medium;">Since the patient <i><u>is</u></i> hemodynamically stable — there is time for <i><u>systematic</u></i> assessment of the rhythm. By the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach (</b><i>See</i> <b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a>):</b></span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><span>The rhythm is fast and QRS complexes are </span><b><span><u>R</u></span>egular</b><span>. Since the R-R interval is just under 2 large boxes in duration — I estimate the ventricular <b><span><u>R</u></span>ate</b> to be <i>just over</i> <b>150/minute</b>.</span></span></li><li><span style="font-family: arial; font-size: medium;"><span><br /></span></span></li><li><span style="font-family: arial;"><i style="font-weight: bold;">QRS morphology varies every-<u>other</u>-beat! </i>This is perhaps best seen in <b>lead V1</b> <b>(</b><i>but also well seen in leads V3,V4,V6</i><b>)</b>. The <b><u>Q</u>RS </b>is <b>narrow</b> in <b><i>odd-numbered</i></b> <b>beats</b> <b>(</b><i>but the QRS is <b>wide</b> in <u>even</u>-numbered beats</i><b>)</b>.</span></li><li><span style="font-family: arial;"><span style="font-size: medium;"><i><br /></i></span></span></li><li><span style="font-family: arial;"><i><b>Sinus</b> </i><b><span><u>P</u></span> waves</b><i> </i>appear to be <i><b>absent</b></i> — because we do <i><u>not</u></i> see a clearly defined upright P wave in lead II. Instead — a <b><i>negative</i></b> <b>deflection</b> appears to precede each QRS complex in <b>lead II (</b><i>and we can see this negative deflection in front of </i><u><i>each</i></u><i> of the 26 beats in the long lead II rhythm strip</i><b>)</b>.</span></li><li><br /></li><li><span style="font-family: arial;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>1:</u> Although we know these negative deflections in front of the QRS <b>are <i><u>not</u></i> sinus P waves</b> <b>(</b><i>because, as noted above — these deflections are <u>not</u> upright in lead II</i><b>)</b> — there <u style="font-style: italic;">does</u> appear to be a fixed interval (<i>distance</i>) between these negative deflections and the QRS complex that follows. This suggests these negative deflections represent some <i><u>other</u></i> form of <b><i><u>atrial</u></i></b> <b>activity (</b><i>that by the 5th parameter in the Ps,Qs,3R Approach</i><b>)</b> — <span style="font-style: italic;"><b>is</b></span> <b><i><u>R</u>elated</i></b> to <i>neighboring</i> QRS complexes.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><div><b><u><br /></u></b></div><div><b><u><i><span style="color: red;">P</span>utting <span style="color: red;">I</span>t <span style="color: red;">A</span>ll <span style="color: red;">T</span>ogether:</i></u></b></div><div>By the Ps, Qs, 3R Approach — We have determined that the rhythm in <u>Figure-1</u> manifests <i>regular</i> QRS complexes at a rate just over 150/minute — with some form of atrial activity that <u style="font-style: italic;">is</u> related to neighboring QRS complexes.</div><div><ul><li><b><i>But WHY is QRS morphology changing</i> every-other-beat? (</b>ie, <i>being <u>narrow</u> for one beat — and then becoming <u>wide</u> for the next beat</i><b>)?</b></li><li> — Is the rhythm in <u>Figure-1</u> supraventricular?</li><li> — What kind of atrial activity is likely to be present? </li></ul></div><div><b><u><br /></u></b></div><div><div><b><u>PEARL <span style="color: red;">#</span>2:</u> </b>The obvious initial consideration whenever we see <i><u>wide</u></i> beats — is that the etiology of such beats may be ventricular. That said (<i>as per PEARL #1</i>) — the fact that <u style="font-style: italic;">each</u> of the 26 beats in the long lead II rhythm strip in <u>Figure-1</u> are preceded by a negative deflection with a <b><i>fixed</i></b> <b>interval</b> between this negative deflection and the QRS complex that follows <b>(</b><i>BLUE arrows in the long lead II in</i> <b><u>Figure-2</u>)</b> — is <u style="font-style: italic;">against</u> these wide beats being ventricular in etiology.</div><div><ul><li>IF the wide beats were ventricular — we would <u style="font-style: italic;">not</u> expect the interval from the negative deflection preceding each QRS to be equal.</li><li>Instead — the fact that the interval from the negative deflection preceding each of the 26 beats in the long lead II rhythm strip remains constant — <b>suggests that each of these 26 beats <u style="font-style: italic;">are</u> being conducted</b> by whatever form of atrial activity these negative deflections represent.</li></ul></div><div><br /></div><div><b><u>PEARL <span style="color: red;">#</span>3:</u></b> QRS morphology of the wide beats strongly supports our presumption that all 26 beats in today's <i><u>initial</u> </i>ECG are <b>supraventricular! (</b><u>Figure-2</u><b>)</b>.</div><div><ul><li>QRS morphology of beats #14,16,18 in <b>lead V1</b> is consistent with <b>RBBB</b> (<i><u>R</u>ight <u>B</u>undle <u>B</u>ranch <u>B</u>lock</i><b>) conduction</b> — because there is an rsR’ morphology, with S wave descending <i>below</i> the baseline <u>and</u> a taller R’ (<i><u>right</u>-“rabbit ear” deflection</i>).</li><li>QRS morphology of beats #2,4,6 in <b>lead I</b> — <u>and</u>, beats #8,10,12 in <b>lead aVL</b> support <b>RBBB conduction </b>— because these lateral leads each manifest a slender, upright R wave with wide terminal S wave (<i>RED arrows in these leads</i>).</li><li><br /></li><li><u>Finally</u> (<i>as shown in Figure-2</i>) — Note that the wide beats in the inferior leads (<i>especially in lead II</i>) manifest a more marked leftward axis, consistent with <b>LAHB (</b><i><u>L</u>eft <u>A</u>nterior <u>H</u>emiBlock</i><b>) aberration</b> — which is yet another suggestion that all wide beats are supraventricular!</li></ul></div><div><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDbIIUy4kGY4xjirwo775r5_UMEIZcKGCYp5ShHOk_MITWEggrxJzj6qvnxdSnDTfiL2JmG5GtIf-QJipy9yr_XynLJytwpRoHepM09nOeZOzPoOzHFFNQD-egIMfCVGVFCkkn4_T7LJJ5HTuugufsAtqpiyADBVpLIJgxqf4BYycXiRapgT_el_7BByw/s3766/Figure-2%20%20ECG-1,%20labeled%20(12-19.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2120" data-original-width="3766" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDbIIUy4kGY4xjirwo775r5_UMEIZcKGCYp5ShHOk_MITWEggrxJzj6qvnxdSnDTfiL2JmG5GtIf-QJipy9yr_XynLJytwpRoHepM09nOeZOzPoOzHFFNQD-egIMfCVGVFCkkn4_T7LJJ5HTuugufsAtqpiyADBVpLIJgxqf4BYycXiRapgT_el_7BByw/w400-h225/Figure-2%20%20ECG-1,%20labeled%20(12-19.1-2023)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b><u>Figure-2:</u></b><span> I've labeled the <b><i><u>initial</u></i></b> <b>ECG</b> in today's case.</span></span></td></tr></tbody></table><br /><div><br /></div><div><b><u>PEARL <span style="color: red;">#</span>4:</u></b> As emphasized in <b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-204-ecg-mp-22-bundle-branch.html" target="_blank">ECG Blog #204</a></b>, in which I review derivation of the bundle branch blocks — <b>RBBB</b> is a <b><i><u>terminal</u></i></b> <b>conduction delay</b>. By this I mean that the <i>initial</i> vectors of ventricular depolarization occur normally when there is RBBB — and <b><i>only the last part of ventricular depolarization is altered</i></b> with this conduction defect.</div><div><ul><li>As a result — the <b>IVS (</b><i><u>I</u>nter<u>V</u>entricular <u>S</u>eptum</i><b>)</b> and the <b>LV (</b><i><u>L</u>eft <u>V</u>entricle</i><b>)</b> depolarize normally with RBBB conduction — and it is only <u style="font-style: italic;">after</u> the LV has depolarized that the <b>RV (</b><i><u>R</u>ight <u>V</u>entricle</i><b>)</b> now depolarizes via slow conduction through ventricular myocardium (<i>because of the "block" in the right bundle branch</i>). This results in terminal depolarization moving toward the “blocked” RV — which writes a <b><i>wide, terminal S wave</i></b> <b><i>in left-sided leads</i></b> <b>(</b><i>with this S wave being wide with complete RBBB — because conduction through myocardium is slow</i><b>)</b>. </li><li> </li><li><b><u><i>KEY</i> Point:</u></b> Awareness that RBBB is a <b><u style="font-style: italic;">terminal</u> conduction delay</b>, with the initial vectors of ventricular depolarization being normal — may provide yet another clue that widened QRS complexes are aberrantly-conducted supraventricular beats. This concept is perhaps best illustrated for the wide beats in <b>lead V1</b> of <u>Figure-2</u> — in which the <i>shape</i> <u>and</u> <i>slope</i> of the tiny initial r-wave, followed by S wave descent in lead V1 looks <i><u>identical</u></i> in shape and slope to the beginning deflections of the narrow beats in this lead. </li></ul></div><div><br /></div><div><b><u><i>Advanced</i> PEARL <span style="color: red;"><span>#</span></span>5</u> (</b> = <i><u>Beyond</u>-the-Core</i><b>):</b> Did <i>YOU</i> notice that there appears to be a <b><i>technical </i>“misadventure” </b>in today's initial ECG — in that the QRS complex does <i><u>not</u></i> look as one should expect with RBBB conduction for the wide beats in <b>lead V6? (</b>ie, <i>for beats #20,22,24,26 in lead V6 of Figure-2</i><b>)</b>.</div><div><ul><li><b><u>To Emphasize</u></b> — that this technical mishap is an extremely subtle finding that I did not notice when I first looked at the initial ECG in today’s case. But since RBBB conduction is the result of a <i>terminal</i> delay in ventricular repolarization — there should be a wide, terminal S wave for wide beats #20,22,24,26 in lateral chest lead V6. Instead, there is a fragmented, <i>all-positive</i> QRS complex in lead V6 <i><u>without</u></i> any terminal S wave.</li><li><br /></li><li><u style="font-weight: bold;">My Theory:</u> I suspect that the V6 lead connection may have inadvertently been reversed with the lead connection for either V4 or V5.</li></ul></div><div><br /></div><div>===================</div><div><b><br /></b></div><div><b>CONTINUED:</b> <b><u><i><span style="color: red;">P</span>utting <span style="color: red;">I</span>t <span style="color: red;">A</span>ll <span style="color: red;">T</span>ogether:</i></u></b></div><div>Now that we’ve established that all 26 beats in today's <i><u>initial</u></i> ECG are supraventricular — We can deduce the following:</div><div><ul><li>There is RBBB conduction every-other-beat in <u>Figure-2</u>. This is a form of <b><i><u>rate</u>-related </i>BBB</b> — in which the rapid ventricular rate may not allow sufficient time between each beat for the right bundle branch to recover.</li><li>Usually, <i><u>rate</u>-related </i>BBB produces QRS widening with <i>every</i> beat — but on occasion, BBB conduction may only occur <i>every-other</i> <u>or</u> <i>every-third</i> beat.</li><li><br /></li><li>This means that the rhythm in today's <i style="text-decoration: underline;">initial</i> tracing — is a <b><i>regular</i></b> <b>SVT (</b><i><u>S</u>upra<u>V</u>entricular <u>T</u>achycardia</i><b>)</b> <b>rhythm</b> at <b>~150/minute</b>, but <i><u>without</u></i> clear sign of sinus P waves. <i>PEARL #6</i> below reviews the differential diagnosis:</li></ul><div><br /></div></div><div><div><span><span style="font-family: arial;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>6:</u><span> As discussed in <b><a href="https://ecg-interpretation.blogspot.com/2022/02/ecg-blog-287-sinus-tach-with-st.html" target="_blank">ECG Blog #287</a></b> — Recognition that the rhythm in today's initial tracing is a <b><i><span>r</span>egular</i></b> <b><span>S</span>VT</b> <i><u>without</u></i> clear sign of sinus P waves <b>(</b>ie, <i><u>without</u> a definite upright P wave in lead II</i><b>)</b> — should prompt consideration of the following <b><i>differential</i></b> <b>diagnosis</b> <b>LIST:</b></span></span></span></div><p class="MsoNormal"></p><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial;"><b><span style="background-color: #fefffe; color: #333333;">i</span></b><b><span style="background-color: #fefffe; color: red;">)</span></b><b><span style="background-color: #fefffe; color: #333333;"> Sinus Tachycardia (</span></b><i><span style="background-color: #fefffe; color: #333333;">IF there is a possibility that sinus P waves might be hiding within the preceding ST-T wave</span></i><b><span style="background-color: #fefffe; color: #333333;">)</span></b><span style="background-color: #fefffe; color: #333333;">; </span></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><span style="background-color: #fefffe; color: #333333;">ii</span></b><b><span style="background-color: #fefffe; color: red;">)</span></b><b><span style="background-color: #fefffe; color: #333333;"> </span></b><span style="background-color: #fefffe; color: #333333;">A<b> <i>Reentry</i> SVT (</b><i>either </i><b>AVNRT</b><i> if the reentry circuit is contained <u>within</u> the AV node — </i><u>or</u><i> </i><b>AVRT</b><i> if an AP [<u>A</u>ccessory <u>P</u>athway] located outside the AV node is involved</i><b>)</b>; </span></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><span style="background-color: #fefffe; color: #333333;">iii</span></b><b><span style="background-color: #fefffe; color: red;">)</span></b><span style="background-color: #fefffe; color: #333333;"> <b>Atrial Tachycardia (</b><i>ATach</i><b>)</b>;</span></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><span style="background-color: #fefffe; color: #333333;">iv</span></b><b><span style="background-color: #fefffe; color: red;">)</span></b><b><span style="background-color: #fefffe; color: #333333;"> Atrial Flutter (</span></b><i><span style="background-color: #fefffe; color: #333333;">AFlutter</span></i><b><span style="background-color: #fefffe; color: #333333;">)</span></b><span style="background-color: #fefffe; color: #333333;"> with <b>2:1 AV conduction</b>. </span></span></li></ul></div><div><br /></div><div><b><u>PEARL <span style="color: red;">#</span>7:</u></b> By far (!) — the most commonly overlooked entity in the above differential diagnosis LIST is <b>AFlutter (</b><i><u>A</u>trial <u>F</u>lutter</i><b>) </b>— especially when the ventricular rate is <b><i>close</i></b> to <b>~150/minute (</b><i>as it is in today's case</i><b>)</b> — <u>and</u> — when there appear to be negative deflections (<i>rather than upright P waves</i>) in lead II.</div><div><ul><li>The reason <b>the ventricular rate in <u style="font-style: italic;">untreated</u> AFlutter tends to be close to 150/minute </b>— is that the atrial rate of flutter in patients <i><u>not</u></i> on antiarrhythmic medication (<i>that might reduce the flutter rate in the atria</i>) — tends to be <b>very close to 300/minute in adults</b> <b>(</b>ie, <i>usual range ~250-350/minute</i><b>)</b>. </li><li>Since the most common ventricular response to <b><u style="font-style: italic;">untreated</u> AFlutter</b> is with <b>2:1 AV conduction</b> — this results in a ventricular rate <i>HALF</i> as fast as the flutter rate in the atria — and 300 ÷ 2 <b>~150/minute (</b><i>usual range ~130-170/minute</i><b>)</b>.</li><li><br /></li><li><b><u><i>KEY</i> Point:</u></b> Knowing that the most commonly overlooked arrhythmia is AFlutter — suggests that the <i>BEST</i> way to avoid missing the diagnosis of AFlutter is simply to <b><i>THINK of AFlutter <u>whenever</u> </i>you have a <i>regular</i> SVT</b> at a rate <b><i>close to </i>150/minute (</b><i>in which you do not clearly see upright sinus P waves in lead II</i><b>)</b>.</li></ul><div><br /></div></div><div><b><u>PEARL <span style="color: red;">#</span>8:</u></b> Using <b><i><u>calipers</u></i></b> facilitates finding the diagnostic <b><i>"<u>sawtooth</u>"</i></b> <b>pattern</b> of AFlutter. When looking for AFlutter — I simply set my calipers at <i>precisely</i> <i>HALF</i> the R-R interval — and then look for leads in which I can <i>"walk out"</i> 2:1 conduction.</div><div><ul><li>I have done this in <u style="font-weight: bold;">Figure-3</u> — in which <i>slanted RED</i> lines in the long lead II rhythm strip highlight negative dips in the baseline that occur at precisely <i>twice</i> the ventricular rate. This corresponds to an <b><i>atrial</i></b> <b>rate</b> of <b>~300/minute</b> <b>(</b><i>P-P interval ~1 large box in duration</i><b>)</b>.</li><li>The <b><i>"sawtooth"</i></b> <b>pattern</b> of the baseline with AFlutter is best appreciated by stepping back a little bit from the rhythm strip. The pattern is best seen in the <b><i><u>inferior</u></i></b> <b>leads (</b> =<i> leads II,III,aVF</i><b>)</b>. The other leads that most often manifest readily identifiable 2:1 atrial activity — are <b>leads aVR</b>, <b>V1</b> <i>and/or</i> <b>V2</b> — so I favor first checking out <b><i>these</i></b> <b>6 leads</b> whenever looking for AFlutter.</li><li><br /></li><li>Physiologically — the most commonly observed pattern of AFlutter, known as <b><i>"<u>Typical</u>"</i></b> <b>AFlutter</b> — produces 2:1 negative deflections seen in the inferior leads <b>(</b><i>as seen in</i> <u>Figure-3</u><b>)</b> — as a result of <b>CCW (</b><i><u>C</u>ounter<u>C</u>lock<u>W</u>ise</i><b>) rotation</b> of a fixed reentrant circuit around the tricuspid valve annulus and through the cavo-tricuspid isthmus. </li><li><b><i>"<u>Atypical</u>"</i></b> <b>AFlutter</b> patterns may occasionally be seen, in which the rotation direction of the reentrant pathway around the tricuspid valve annulus changes to <b>CW (</b><i><u>C</u>lock<u>W</u>ise</i><b>)</b> — in which case smaller positive deflections may be seen.</li><li><u><b>Clinically:</b></u> Initial treatment of AFlutter is the same, <i><u>regardless</u></i> of whether the rotation direction is CW or CCW — so this distinction is <i><u>not</u></i> important to the emergency provider <b>(</b><i>Cosio — </i><b><a href="https://www.aerjournal.com/articles/atrial-flutter-typical-and-atypical-review" target="_blank">Arrhythmia & EP Review 6(2):55-62, 2017</a></b><b>)</b>. The point to remember is that <b>IF you are able to identify regular 2:1 atrial activity at an atrial rate close to 300/minute</b> <b>(</b>with a P-P interval ~1 large box in duration<b>)</b> — then the rhythm is <b><i>almost</i></b> <b>certain</b> to be <b>AFlutter</b>.</li></ul><div><br /></div></div></div><div><b><u>The <span style="color: red;">C</span>ASE <span style="color: red;">C</span>ontinues<span style="color: red;">:</span></u></b></div><div>The patient was treated with <b>IV Amiodarone</b> — which <b>(</b><i>as shown in </i><u>Figure-3</u><b>)</b> successfully converted the AFlutter into normal sinus rhythm.</div><div><ul><li>Although significant baseline artifact is seen in <u>ECG #2</u> — regular upright sinus P waves can be seen in the long lead II rhythm strip.</li><li>RBBB is <u style="font-style: italic;">no</u> longer seen after conversion to sinus rhythm — which supports our suspicion that the <b><i>intermittent</i></b> <b>RBBB</b> conduction seen <i>every-other-beat</i> during the tachycardia (<i>in Figure-1</i>) was <b><i><u>rate-related</u></i></b>.</li><li>Note that QRS morphology after conversion to sinus rhythm is very similar to QRS morphology of <i>odd-numbered</i> beats during the tachycardia.</li><li>Note also that modest T wave inversion persists after conversion to sinus rhythm <b>(</b><i>seen in leads III; and in V1-thru-V4</i><b>)</b>. This most likely reflects a transient and benign <b><i>"<u>Memory</u>"</i></b> <b>effect </b><b>(</b>ie, <i>Not uncommonly — non-ischemic ST-T wave abnormalities may be seen for hours or even days following a sustained tachycardia</i><b>)</b>.</li></ul></div><div><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8swD8wkvsq1DJdLiaj91cSpHoITQoaKhbXN0q7TzF57x8ZTcKFI-IjATGRHhGdiiz02tYWHqgFaCIHoorcS9PpgA_FNpmH1jbHxTYzJCL9nwhBh437SVpa1vUhEk9FnoJ9EK7LcsvYa8_imFiupUza7tS6S4Hw-Ge_63SsmY9STGJgG8frgEjGxwygo0/s2862/Figure-3%20%20ECGs-1,2%20(12-20.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2862" data-original-width="2584" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj8swD8wkvsq1DJdLiaj91cSpHoITQoaKhbXN0q7TzF57x8ZTcKFI-IjATGRHhGdiiz02tYWHqgFaCIHoorcS9PpgA_FNpmH1jbHxTYzJCL9nwhBh437SVpa1vUhEk9FnoJ9EK7LcsvYa8_imFiupUza7tS6S4Hw-Ge_63SsmY9STGJgG8frgEjGxwygo0/w361-h400/Figure-3%20%20ECGs-1,2%20(12-20.1-2023)-USE.png" width="361" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b><u>Figure-3:</u></b><span> Slanted <i>RED lines</i> in the long lead II rhythm strip of <u>ECG #1</u> — highlight the <b><i>"<u>sawtooth</u>"</i></b> <b>pattern</b> of <b>AFlutter</b>.</span></span></td></tr></tbody></table><br /><div><span style="text-align: left;"><br /></span></div><div style="text-align: justify;"><span style="text-align: left;"><b>And a <i><u>Final</u></i> Tracing ...</b></span></div><div style="text-align: justify;"><span style="text-align: left;">As a final </span><i style="text-align: left;"><u>advanced</u></i><span style="text-align: left;"> concept — I add one more tracing in </span><u style="font-weight: bold; text-align: left;">Figure-4</u><span style="text-align: left;">.</span></div><div style="text-align: justify;"><ul><li style="text-align: justify;"><u style="font-weight: bold; text-align: left;">ECG #3</u><span style="text-align: left;"> was obtained during treatment of this patient's AFlutter — at approximately the same time that </span><u style="text-align: left;">ECG #1</u><span style="text-align: left;"> was obtained.</span></li><li style="text-align: justify;"><span style="text-align: left;"><br /></span></li><li style="text-align: justify;"><span style="text-align: left;">As I noted earlier in <i style="text-decoration: underline;"><b>advanced</b> </i><b style="text-decoration: underline;">PEARL <span style="color: red;">#</span>5</b> — lack of a wide terminal S wave for the wide beats in lead V6 of <u>ECG #1</u> did not make physiologic sense, given that beats #20,22,24,26 were conducted with RBBB aberration <b>(</b><i>within the RED rectangle in </i><u>Figure-4</u><b>)</b>. I suspected<i> some type of lead connection "technical misadventure".</i></span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="text-align: left;">I believe <u>ECG #3</u>, which was obtained during the treatment process — supports my theory. Note that rather than every-other-beat RBBB conduction — rate-realted RBBB aberrancy is seen <i>every beat</i> in <u>ECG #3</u> — and, a <b><i>terminal</i> S wave (</b><i>albeit a notched deflection</i><b>)</b> <u>is</u> indeed seen in <b>lead V6</b>. As expected — wide terminal S waves are seen in the other lateral leads in <u>ECG #3</u> <b>(</b><i> = in leads I and aVL</i><b>)</b>.</span></li></ul></div></span></div></div></span><div><div style="text-align: left;"><br /></div><div style="text-align: left;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjYQPRLi6ZgB5al-s4q5q8-FFngL9X4En-VsJv7hIJS7VzqtrKjiMsanlhhShBsoPc1MUJUZ3EAYKLuYDVZq-PkAg8z4dESro6nAGUyQgOWSorRePMlTZcw1ipOMgDP4J_jValUZnXGmwnieSmIO2fZZ4Y-ImwcS2fDMb-VS78ENZRua-iZV_dniR0Nscs/s2856/Figure-3%20ECGs-1,3%20(12-19.24-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2856" data-original-width="2592" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjYQPRLi6ZgB5al-s4q5q8-FFngL9X4En-VsJv7hIJS7VzqtrKjiMsanlhhShBsoPc1MUJUZ3EAYKLuYDVZq-PkAg8z4dESro6nAGUyQgOWSorRePMlTZcw1ipOMgDP4J_jValUZnXGmwnieSmIO2fZZ4Y-ImwcS2fDMb-VS78ENZRua-iZV_dniR0Nscs/w363-h400/Figure-3%20ECGs-1,3%20(12-19.24-2023)-USE.png" width="363" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b><u>Figure-4:</u></b><span> Confirmation of the "technical misadventure" I described earlier in <i><u>advanced</u></i> PEARL #5 (<i>See text</i>).</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span style="text-align: justify;"><br /></span></span></div><div style="text-align: left;"><br /></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><div><span style="font-family: arial; font-size: medium;"><div><span style="color: #333333; font-family: arial;">==================================</span></div><div><span style="font-family: arial;"><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Chun-Hung Chen = </span><span style="text-align: start;">陳俊宏 </span>(<i>from Taichung City, Taiwan</i>) for the case and this tracing.</div><div><span style="color: #333333; font-family: arial; text-align: left;">==================================</span></div><div><span style="color: #333333; font-family: arial; text-align: left;"><br /></span></div></span></div><div><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div><span><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></div><div><p class="MsoNormal"></p><ul><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span style="color: red;">S</span>ystematic</i></b> <b><span style="color: red;">A</span>pproach</b> to 12-lead ECG Interpretation.</span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — Reviews the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach</b> to Rhythm Interpretation.</span></li><li style="text-align: justify;"><i><br /></i></li><li style="text-align: justify;"><i>See</i> <b><a href="https://ecg-interpretation.blogspot.com/2021/07/ecg-blog-240-55-what-kind-of-regular-svt.html" target="_blank">ECG Blog #240</a></b> — for Review on the ECG assessment of the patient with a <b><i><u>regular</u></i></b> <b>SVT rhythm (</b><i>including distinction between the various types of SVT reentry</i><b>)</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2022/02/ecg-blog-287-sinus-tach-with-st.html" target="_blank">ECG Blog #287</a></b> — for a <b><i>regular</i></b> <b>SVT</b> that was <b>AFlutter</b>.</li><li style="text-align: justify;"><i>See</i> <b><a href="https://ecg-interpretation.blogspot.com/2021/09/ecg-blog-250-64-st-depression-and.html" target="_blank">ECG Blog #250</a></b> — for a <b><i>regular</i></b> <b>SVT</b> <i><u>with</u></i> <b>ST depression</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-229-45-is-this-vt-or-something.html" target="_blank">ECG Blog #229</a></b> — reviews distinction between <b>AFlutter</b> <i><u>vs</u></i> <b>ATach (</b><i>and WHY AFlutter is so commonly overlooked</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;">The <b><a href="https://hqmeded-ecg.blogspot.com/2019/11/what-is-this-regular-svt.html" target="_blank">November 12, 2019</a> post</b> in Dr. Smith's ECG Blog — in which I review my approach to a <b><i>Regular </i>SVT rhythm</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/04/blog-210-ecg-mp-27-regular-wct-how-fast.html" target="_blank">ECG Blog #210</a></b> — reviews the <b><i>Every-Other-Beat</i></b> <b>Method</b> for estimation of heart rate when the rhythm is very fast.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-220-ecg-mp-37-vt-or-aberrancy.html" target="_blank">ECG Blog #220</a></b> — reviews my <b><u><span>L</span></u></b><b><u>IST </u></b><b><u><span>#</span></u></b><b><u>1</u></b><b><u><span>:</span></u></b><b> Causes </b>of a <b><i>regular</i></b> <b>WCT (</b><i>and how to assess hemodynamic stability</i><b>)</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/07/ecg-blog-242-57-why-wide-beats-mobitz-i.html" target="_blank">ECG Blog #242</a></b> — Reviews <b><i><u>rate</u>-related</i> BBB</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2011/11/ecg-interpretation-review-32-bundle.html" target="_blank">ECG Blog #32</a></b> — More on <b><i>rate-related</i></b> <b>BBB</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;">The <b><a href="https://hqmeded-ecg.blogspot.com/2020/08/35-year-old-with-palpitations-and-very.html" target="_blank">August 17, 2020</a> post</b> by me in Dr. Smith's ECG Blog — in which I review the phenomenon of <b><i>Bradycardia-dependent</i></b> <b>BBB (</b><i>sometimes called "Phase 4" or "paradoxical" block</i><b>)</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/04/ecg-blog-211-ecg-mp-28-why-does.html" target="_blank">ECG Blog #211</a></b> — Reviews <i>WHY</i> some early beats and some SVT rhythms are conducted with <b>Aberration (</b><i>and why aberrant beats usually look like some form of conduction block</i><b>)</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-203-ecg-mp-2021-axis.html" target="_blank">ECG Blog #203</a></b> — reviews ECG recognition of the <b>Hemiblocks</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-204-ecg-mp-22-bundle-branch.html" target="_blank">ECG Blog #204</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2022/02/ecg-blog-282-lbbb-and-sgarbossa-lvh-mi.html" target="_blank">ECG Blog #282</a></b> — reviews ECG recognition of the <b>Bundle Branch Blocks</b>.</li></ul></div><div><br /></div><div><br /></div></div></span></span></div></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div style="text-align: justify;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"></div><span style="font-family: arial; font-size: medium;"> <br /><div style="text-align: justify;"><b><u><span face="Arial, sans-serif" style="color: red;">A</span></u></b><span face="Arial, sans-serif"><b style="text-decoration: underline;">DDENDUM</b><b> </b><b style="text-decoration: underline;"><span style="color: red;">(</span></b><i>12/23/2023</i><b><span style="color: red;">)</span>:</b></span></div></span></div></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">I've presented this material before — but it bears repeating for reference. These concepts should be automatic for assessment of the patient who presents with a regular SVT rhythm.</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><a href="https://dl.dropbox.com/s/lurjo2lqy8h5lt7/z-ECG-Audio%20Pearl-64%20Regular%20SVT%20%289-7.1-2021%29-USE.mp3?dl=0" target="_blank"><span style="font-family: arial;">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1370" data-original-width="2048" height="268" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXDSWcH158Jo8cD0T4f20dAVd5K-6F8euClgfDvCiOJ8Ko6gP6FINTDJY9qpjStnxapw40r94kn437kOUQSVZpVt5ucklrATj5fKr2r8YGBfJP7TQ52nrmUkwYSdOocP5uhUXN-nLiNFY/w400-h268/ECG-MP-64+Causes+of+Regular+SVT+%25289-7.1-2021%2529-USE.png" width="400" /></span> —</span></a></div><div style="text-align: center;"><span style="font-family: arial;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiZhTtOUcyujsWjvYAOKmx-dJc6tcz2ufLJSCucCEtEohlcyZ4bxR-fqE6J05VYKOlYg79-HOHKnOujJAYV5_s2fi0zrUejFJXtJ_Ngk_10XjkFGGlISFkMRxKEMUZuN4QIFjAgy2FMG6k/s2565/Figure-2a-MP-64+Causes+of+Regular+SVT+%25289-6.21-2021%2529-USE.png" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: arial;"><img border="0" data-original-height="1225" data-original-width="2565" height="191" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiZhTtOUcyujsWjvYAOKmx-dJc6tcz2ufLJSCucCEtEohlcyZ4bxR-fqE6J05VYKOlYg79-HOHKnOujJAYV5_s2fi0zrUejFJXtJ_Ngk_10XjkFGGlISFkMRxKEMUZuN4QIFjAgy2FMG6k/w400-h191/Figure-2a-MP-64+Causes+of+Regular+SVT+%25289-6.21-2021%2529-USE.png" width="400" /></span></a></div><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial;"><b><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>64 (</b><i>10:50 minutes</i> <b><i><u>Audio</u></i>)</b> — Reviews my <b><u><span style="color: red;">L</span>IST <span style="color: red;">#</span>2<span style="color: red;">:</span></u> <i>Common</i> Causes </b>of a <b><i>Regular</i> SVT Rhythm</b>.</span></p></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">===================================</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial;"><a href="https://dl.dropbox.com/s/hzzw20sl0o4gaxa/z-ECG-Audio%20Pearl-45%20AFlutter%20%285-28.1-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1488" data-original-width="2048" height="290" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiegNbPu2Cm145GFyaLv_cwZEoMLvc7XZux_r4_cmf12J0v0oYlQ3q3FEWY_1mxq6A8rD9TSQCofHMDhYtEb-a5BfOSkxmLcjCClF7vgeyTvrJ6Od1H-XK85OvIN_b9ZTrB1r5GURqKGr8/w400-h290/ECG-MP-45+AFlutter+%25285-28.1-2021%2529-USE.png" width="400" /></span> —</a></span></div><p style="text-align: left;"></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial;"><b><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>45 (</b><i>10:00 minutes <b><u>Audio</u></b></i><b>)</b> — Why is <b><i><span style="color: red;">A</span>trial </i><span style="color: red;">F</span>Iutter</b> so commonly overlooked? Reviews PEARLS regarding the ECG diagnosis of AFlutter — <u>and</u> — <b><i>What's "New"?</i></b> in the field, regarding <b>distinction <i>between</i> AFlutter</b> <u>vs</u> <b>Atrial Tachycardia (</b><i>5/29/2021</i><b>)</b>.</span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial;"><br /></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropbox.com/s/pyi3l2209tgnrnp/z-ECG-Audio%20Pearl-57%20Rate-Related%20BBB%20%287-13.1-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1410" data-original-width="2048" height="275" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjIvFUuFaNTZBo2XWpEB9CpsEwVVOuzWKhtFBBgx6RgPtgq9X4wobMvQFqgp4EwE6STK1HH21uuRmyf792i_k51ndlTjerfOCvM12YpQNswneM3QPL4T3UFcjK8HcBAnuzsOYtNb3hPihY/w400-h275/ECG-MP-57+What+is+Rate-Related+BBB+%25287-13.1-2021%2529-USE.png" width="400" /></span> —</a></span></div><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial;"><span style="font-family: arial; font-size: medium; text-align: left;"></span></span></p><div style="text-align: justify;"><b><span style="color: red;">E</span><span style="font-style: italic;"><span style="font-style: normal;">CG</span> <span style="color: red; font-style: italic;">M</span>edia</span><i> </i><span style="color: red;">P</span>EARL <span style="color: red;">#</span>57 (</b><i style="font-style: italic;">8:00 minutes</i><i> </i><b><i style="font-style: italic;"><u>Audio</u></i>)</b> — What is<b><i style="font-style: italic;"> <u><span style="color: red;">r</span>ate-<span style="color: red;">r</span>elated</u></i><i> </i><span style="color: red;">B</span>undle <span style="color: red;">B</span>ranch <span style="color: red;">B</span>lock<span style="color: red;">?</span></b><i> How does this differ from "aberrant" conduction.</i></div></span></div><p></p><div style="text-align: justify;"></div><p></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="cursor: move;" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: justify;"><br /></div><div class="separator" style="clear: both; text-align: justify;"><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p></div><div class="separator" style="clear: both; font-family: arial; text-align: justify;"><br /></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com2tag:blogger.com,1999:blog-3364570834099131201.post-3172293414511496172023-12-16T00:03:00.000-05:002023-12-16T00:03:22.842-05:00ECG Video Blog #408 (392) — 20 Minutes Later ... <span style="font-family: arial; font-size: medium;"><br /></span><div><div style="text-align: justify;"><div><div><span style="color: #050505; font-family: arial; font-size: medium;">======================================</span></div><div><span><span style="font-family: arial; font-size: medium;"><span style="color: #050505;"> </span><b style="color: #050505;"><a href="https://www.youtube.com/watch?v=YP0VJ8noNp4" target="_blank">CLICK HERE</a></b><i style="color: #050505;"> — for a </i><u style="font-weight: bold;"><span style="color: red;">V</span><span style="color: #050505;">ideo</span></u><span style="color: #050505;"> presentation of this case! (<i>18:00 min.</i>)</span></span></span></div><p class="MsoNormal" style="margin: 0in;"></p><ul><li><span style="color: #050505; font-family: arial; font-size: medium;">Below are slides used in my video presentation.</span></li><li><span style="color: #050505; font-family: arial; font-size: medium;">For full discussion of this case — <i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2023/08/ecg-blog-392-repolarization-t-waves.html?fbclid=IwAR3ttHGO9mzn0bMwiDbrN7_D8-U12YmiVBYhvv20H7hxHhMzuD0L-nu1dPw" target="_blank">ECG Blog #392</a> </b>—</span></li></ul><p></p><div><span style="color: #050505; font-family: arial; font-size: medium;">======================================</span></div></div></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div><div class="separator" style="clear: both;"><div><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><span>The ECG</span> in <b><u>Figure-1</u></b> was obtained from a man in his 60s — who described the sudden onset of <b><i>"chest tightness"</i></b> that began 20 minutes earlier, but who now <b>(</b><i>at the time this ECG was recorded</i><b>)</b> — was <i><u>no</u></i> <u>longer</u> having symptoms.</span></div><div><div><ul><li><span style="font-family: arial; font-size: medium;">In view of this history — <i>How would YOU interpret this ECG?</i></span></li><li><span style="font-family: arial; font-size: medium;"><i>Should the <b>cath</b> </i><b>lab</b><i> be activated? </i></span></li></ul></div></div></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: auto; margin-right: auto;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhC4di-emzJ1QpGkTeiT8a2N4QEljrg-fEq238WIiCX4Et8VFeMSRdmgyoM5mZyT4Le9Or43IVIsXqPR9QZ9b-6kFXvz1vjFCDbLIxyM6J5gBEVw_zpJhAnWoy7FTBzFbyTKMx82KKyqfyjqVB6EBy6m5drx_EmBGyOwf2FvaQfj3f2xQQxyub-CTd40VQ/s3794/Figure-1%20%20ECG-1%20No%20CP%20(8-10.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1502" data-original-width="3794" height="159" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhC4di-emzJ1QpGkTeiT8a2N4QEljrg-fEq238WIiCX4Et8VFeMSRdmgyoM5mZyT4Le9Or43IVIsXqPR9QZ9b-6kFXvz1vjFCDbLIxyM6J5gBEVw_zpJhAnWoy7FTBzFbyTKMx82KKyqfyjqVB6EBy6m5drx_EmBGyOwf2FvaQfj3f2xQQxyub-CTd40VQ/w400-h159/Figure-1%20%20ECG-1%20No%20CP%20(8-10.21-2023)-USE.png" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><span><b style="text-align: justify;"><u>Figure-1:</u></b><span style="text-align: justify;"> </span></span><span>The initial ECG in today's case. </span><b>(</b><i>To improve visualization — I've digitized the original ECG using</i><span> </span><b><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span>.</span></span></div><div class="separator" style="clear: both; text-align: center;"><br /></div><br /><div class="separator" style="clear: both; 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margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="2584" data-original-width="3304" height="313" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6rMuqWIbLvQHZrmtxAkC0K5P5mUrEj8UYW2cfSmMb-BK49YRyQMTC_z0tyftdGu2pdBqr8bp6lvCJryu0lpKHbJXm26XZCkbHL1jWE-d_368AlaiQJlR_ZpwZb2D7CFtH6nwEZAi5IJs68Ovj_pOLpjHLbQGC6anBhnpH3ZmcuAg2KnTYNuF5qeflIbQ/w400-h313/11-ECGs-1,2%20Comparison.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span><b style="text-align: justify;"><u>Figure-2:</u></b><span style="text-align: justify;"> </span></span><span>Comparison between the 2 ECGs recorded in today's case. <u style="font-weight: bold;">ECG #2</u> was actually done first, at the time the EMS unit arrived on the scene <b>(</b><i>at which time the patient was having severe chest pain</i><b>)</b>. About 20 minutes later <b>(</b><i>on the way to the hospital</i><b>)</b> — the patient's CP resolved, and <u style="font-weight: bold;">ECG #1</u> was recorded. </span></span></td></tr></tbody></table><br /></div><div><br /></div></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg4itBju0JFA5ZLElYkt-zMK_V_IZWqqxKjxGZhhUanm9A49GG6pY__ZP9PWAMkUpVvA4TqB4pQV38HDjSZY70Vx-dSA0amY0_W-C58M0FK-euqdgzTdEbkP-A-ylcSyALA3lK6mnv89obLT8PiON0bYRakd4IPm6i5NIJ5wSqEygYGs5O2_7ZB1LfWEU0/s2884/Many%20clinicians%20stuck%20on%20STEMI%20Paradigm.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="878" data-original-width="2884" height="121" 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style="color: red;">:</span></u></b></span></div><div><p class="MsoNormal"></p><ul><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span style="color: red;">S</span>ystematic</i></b> <b><span style="color: red;">A</span>pproach</b> to 12-lead ECG Interpretation.</span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — Reviews the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach</b> to Rhythm Interpretation.</span></li><li style="text-align: justify;"><span>mmm</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-193-ecg-mp-10-acute-omi.html" target="_blank">ECG Blog #193</a> </b>— Reviews the concept of why the term <b>“OMI” (</b> = <i><u>O</u>cclusion-based <u>MI</u></i><b>)</b> should <i><u>replace</u></i> the more familiar term STEMI — <u>and</u> — reviews the basics on how to <b><i>predict</i></b> the <b><i>"<u>culprit</u>" </i>artery</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: #050505;"><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-194-ecg-mp-11-reperfusion-of.html" target="_blank">ECG Blog #194</a> </span></b><span style="color: #050505;">— Reviews how to tell IF the <b>“culprit” (</b>ie, <i>acutely occluded</i><b>)</b> artery has <i><b><u>reperfused</u></b></i> using clinical and ECG data.</span></span></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2022/03/ecg-blog-294-one-hour-later.html" target="_blank">ECG Blog #294</a></b> — How to tell IF the <b><i>"culprit" </i>artery</b> has <b><u>reperfused</u></b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-183-repolarization-variant.html" target="_blank">ECG Blog #183</a></b> — Reviews the concept of <b><i>de<span style="color: red;">W</span>inter</i></b> <b><span style="color: red;">T</span></b><b>-</b><b><span style="color: red;">W</span></b><b>aves (</b><i>with reproduction of the illustrative Figure from the original deWinter NEM manuscript</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2022/07/ecg-blog-318-stroke-but-no-chest-pain.html" target="_blank">ECG Blog #318</a></b> — <b><a href="https://ecg-interpretation.blogspot.com/2022/10/ecg-blog-340-evolution-to-make-note-of.html" target="_blank">ECG Blog #340</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2022/10/ecg-blog-341-why-are-t-waves-peaked_29.html" target="_blank">ECG Blog #341</a></b> — More on <b><i>deWinter</i></b> and<b> <i>deWinter-<u>like</u> </i>T waves</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/04/ecg-blog-218-ecg-mp-35-what-is.html" target="_blank">ECG Blog #218</a></b> — Reviews <i>HOW</i> to define a <b><span style="color: red;">T</span> wave</b> as being <b><span style="color: red;">H</span>yperacute<span style="color: red;">?</span></b></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-260-repolarization-change.html" target="_blank">ECG Blog #260</a></b> — <b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-222-39-are-there-dynamic-st-t.html" target="_blank">ECG Blog #222</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2022/03/ecg-blog-292-why-did-patient-die.html" target="_blank">ECG Blog #292</a> </b>— Reviews when a T wave is <b><i><u>hyperacute</u></i></b> — and the concept of <b><i>"<u>dynamic</u>" </i>ST-T wave changes</b>.</li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2023/07/ecg-blog-387-2-minutes-later.html" target="_blank">ECG Blog #387</a></b> — Dynamic change in 2 minutes.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/06/ecg-blog-230-46-are-there-serial-ecg.html" target="_blank">ECG Blog #230</a></b> — How to <b><i><u>compare</u></i></b> <b><i>serial</i></b> <b>ECGs</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2015/07/ecg-blog-115-early-repolarization.html" target="_blank">ECG Blog #115</a></b> — Shows an example of how drastically the ECG may change in <i>as little as</i> <b>8 minutes</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2022/10/ecg-blog-337-nstemi-or-omi.html" target="_blank">ECG Blog #337</a></b> — an <b>OMI</b> <i><u><b>misdiagnosed</b></u></i> as an <b>NSTEMI</b> ...</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-184-audio-pearl-2-magical-lead.html" target="_blank">ECG Blog #184</a></b> — illustrates the <b><i>"magical"</i></b> <b>mirror-image opposite relationship</b> with acute ischemia between <b>lead III</b> <u>and</u> <b>lead aVL (</b><i>featured in Audio Pearl #2 in this blog post</i><b>)</b>. </li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2019/07/ecg-blog-167-reciprocal-omi-normal.html" target="_blank">ECG Blog #167</a></b> — another case of the <b><i>"magical"</i> mirror-image opposite relationship</b> between <b>lead III</b> <u>and</u> <b>lead aVL </b>that confirmed acute OMI.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-271-79-what-is-st-segment.html" target="_blank">ECG Blog #271</a></b> — Reviews determination of the ST segment baseline <b>(</b><i>with discussion of the entity of </i><b><i>diffuse Subendocardial</i> Ischemia)</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/10/ecg-blog-258-mp-70-how-to-date-mi.html" target="_blank">ECG Blog #258</a></b> — How to <b><i>"<u><span>D</span>ate</u>"</i></b> an <b><span>I</span>nfarction</b> based on the <i>initial</i> ECG.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;">The importance of the <b><i><u>new</u></i></b> <b>OMI (</b><i>vs the old STEMI</i><b>) Paradigm</b> — See <i>My Comment </i>in the <b><a href="https://hqmeded-ecg.blogspot.com/2020/07/omi-nomi-paradigm-established-as-better.html" target="_blank">July 31, 2020</a> post</b> in Dr. Smith's ECG Blog.</li><li style="text-align: justify;">For review on when despite acute OMI — the <b><i>initial</i></b> <b>hs-troponin</b> may come back normal — <i>See the </i><b><a href=" http://hqmeded-ecg.blogspot.com/2023/03/85-year-old-with-chest-pain-stemi.html" target="_blank">March 24, 2023</a> post</b> <i>in Dr. Smith’s ECG Blog.</i></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial;">The <b><a href="http://hqmeded-ecg.blogspot.com/2019/01/a-patient-with-chest-pain-and-dynamic.html" target="_blank">January 9, 2019</a> post</b> in Dr. Smith's ECG Blog <b>(</b><i>Please scroll down to the <u>bottom</u> of the page to see </i><b><i>My Comment</i>)</b></span>. This case is remarkable for the <b><i><u>dynamic</u></i></b> <b>ST-T wave changes</b> that are seen. It's helpful to appreciate: <b>i<span style="color: red;">)</span> </b>That acute ischemia/infarction is <i><u>not</u></i> the only potential cause of such changes (<i>cardiac cath was normal</i>); <b>ii<span style="color: red;">)</span></b> That changes in heart rate, frontal plane axis <i>and/or</i> patient positioning can <i><u>not</u></i> always explain such changes; <u>and</u>, <b>iii<span style="color: red;">)</span></b> That entities such as repolariztion variants, LVH <i>and/or</i> acute myopericarditis may <i><u>all</u></i> contribute on occasion to produce an evolution of challenging <i>dynamic</i> ST-T wave changes on serial ECGs.</li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial;">The <b><a href="http://hqmeded-ecg.blogspot.com/2020/08/dynamic-st-change-in-mid-50s-man-with.html" target="_blank">August 22, 2020</a> post</b> in Dr. Smith's ECG Blog — which illustrates another case of <b><i>dynamic</i></b> <b>ST-T wave changes</b> that resulted from a <b><i>repolarization</i></b> <b>variant</b>. </span></li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial;">The <b><a href="https://hqmeded-ecg.blogspot.com/2018/07/an-athletic-30-something-woman-with.html" target="_blank">July 31, 2018</a> post</b> in Dr. Smith's ECG Blog <b>(</b><i>Please <b>scroll down</b> to the <b><u>bottom</u></b></i> <i>of the page to see </i><b><i>My Comment</i>)</b>. This case provides an excellent example of <b><i><u>dynamic</u></i> ST-T wave changes</b> on serial tracings in a patient with an <b>ongoing <i>acutely</i> <i>evolving</i> infarction</b></span>. </li></ul></div><div><br /></div></div></span></span></div><p class="MsoNormal"><span style="font-family: arial; font-size: medium;"></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: justify;"><span style="font-family: arial; font-size: medium;"><div><span style="font-family: arial; font-size: medium;">=======================</span></div><div><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">A</span>DDENDUM<span style="color: red;">:</span></u></b> Some <i>additional</i> material on ECG diagnosis of OMI.</span></div><div><span style="font-family: arial; font-size: medium;">=======================</span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsc51OgG0h2T3wkOY6owXlTXLVFs78En7dJI2mJRFklnODHM5M88EKhk6hikoMJn7BOGskYhyg3DsyEQnneLs5jrsa1uGMXCiALn52UNOk6g9pDhEG8bQ0Yw8OVmyhIJM5DVzgQOf_0rugBj_AJbQQm-yxu5-Bz8z_cx7Mo5kceivr1UsjTq6malMfv9Q/s1712/01L-%20How%20to%20Compare%20Serial%20ECGs-USE%20copy.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="860" data-original-width="1712" height="201" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsc51OgG0h2T3wkOY6owXlTXLVFs78En7dJI2mJRFklnODHM5M88EKhk6hikoMJn7BOGskYhyg3DsyEQnneLs5jrsa1uGMXCiALn52UNOk6g9pDhEG8bQ0Yw8OVmyhIJM5DVzgQOf_0rugBj_AJbQQm-yxu5-Bz8z_cx7Mo5kceivr1UsjTq6malMfv9Q/w400-h201/01L-%20How%20to%20Compare%20Serial%20ECGs-USE%20copy.png" width="400" /></a></div><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglMLqA1BTUwX_r40-DSBrppHIBjt1VHvLMFaHmm7xYKA6fQr8-E-hPNKLd51_KG29UJnn0JZ7Zoi73J9r_sfn1l8P4N02tzSBQpA4ASJs8D5OlL4RAQxFfZ1CJGJOzKyh3R5o9iSRMLUe-WaAEvEIb9j1e_ZsvIBiueZuxltH5fj758tk9VBthCcVWa-I/s2898/03d-%20Figure-13%20ECG%20Findings%20for%20Acute%20OMI%20(10-29.1-2023)-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2330" data-original-width="2898" height="321" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglMLqA1BTUwX_r40-DSBrppHIBjt1VHvLMFaHmm7xYKA6fQr8-E-hPNKLd51_KG29UJnn0JZ7Zoi73J9r_sfn1l8P4N02tzSBQpA4ASJs8D5OlL4RAQxFfZ1CJGJOzKyh3R5o9iSRMLUe-WaAEvEIb9j1e_ZsvIBiueZuxltH5fj758tk9VBthCcVWa-I/w400-h321/03d-%20Figure-13%20ECG%20Findings%20for%20Acute%20OMI%20(10-29.1-2023)-USE.png" width="400" /></a></div><div class="separator" style="clear: both; text-align: center;"><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">==================================</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><span style="text-align: center;">I've added several </span><b style="text-align: center;"><i><u>Audio</u></i></b><span style="text-align: center;"> </span><b style="text-align: center;">Pearls</b><span style="text-align: center;"> below with material relevant to today's case.</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropboxusercontent.com/s/y03g4vnr4ww7r1c/z-ECG%20Audio%20Pearl-1%20%282-12.1-2021%29-USE-Faster.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1330" data-original-width="2048" height="260" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgvI2HM58bWaBtt3jDMdsUVdwLYwGDknzl4dK0jBnoFDlKStnDL9Jp9tKIc3at19k7BcvhVQen5ubOyE46zLYHq_ftNShldTdF7ELoXAzLRUHYRLRpxaKxlYkkw4ZdXSIj-Qa0B8k9e13U/w400-h260/ECG-MP-1+deWinter+T+Waves+%252811-3.21-2021%2529-USE.png" width="400" /></span> —</a><span style="text-align: justify;"> </span></span></div><p style="text-align: left;"></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><i>Today’s</i> <b><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>1 (</b><i>3:00 minutes <b><u>Audio</u></b></i><b>)</b> — Reviews the concept of <b><i><span style="color: red;">d</span>e<span style="color: red;">W</span>inter</i> <span style="color: red;">T</span> waves</b> <b>(</b><i>and the common occurrence of</i> <b><i>variations</i></b> <i>on this "theme"</i> <b>)</b>.<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><div class="separator" style="clear: both;"><a href="https://dl.dropbox.com/s/psv56q64pjlbjrl/z-ECG%20Audio%20Pearl-35a%20Hyperacute%20T%20Wave%20%2811-4.1-2021%29%20FASTER-Use.mp3?dl=0" target="_blank"><span style="font-family: arial; font-size: medium;">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1353" data-original-width="2048" height="264" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhHtawkv3Q4xdA8XDf89bGYctiy5eqf05KP7LnGmZ9sAEIlQPS7XXbXXS0e3GvL5EGfDJB8VzJLn5QMubdxUzEkUgcuFYzW1nDM1BJcVfYAKmVV_UvfSdbCTdggekQ2t9QddrFGVXs4S80/w400-h264/ECG-MP-35a+Hyperacute+T+%252811-4.21-2021%2529-USE.png" width="400" /></span> —</span></a></div><p style="text-align: left;"></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;"><br /></span></b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;"><br /></span></b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span></b><b>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>35a (</b><i>4:50 minutes <b><u>Audio</u></b></i><b>)</b> — <i>WHEN</i> is a <b><span style="color: red;">T</span> Wave <span style="color: red;">H</span>yperacute</b> <u>vs</u> a <i>Repolarization </i>variant?</span></p></span></div><div><span style="font-family: arial; font-size: medium;"><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><div class="separator" style="clear: both;"><span style="font-family: arial; font-size: medium;"><span><a href="https://dl.dropbox.com/s/53c2h2p37ld2y95/z-ECG%20Audio%20Pearl-39a%20Dynamic%20ST-T%20%2811-3.21-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1540" data-original-width="2048" height="301" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi46YyU9sfDJJXy3xrDieL__7t8YCL7_5jiUHOIgYuo5Lv8yyPlPlW2jka16OoA7UZlYLniBaaaBoeqPjAHhtXfP4qYybRknLHM4hAkP8mWk5NSMERKYY8jniE7l3bmrtI__Ab-NQp0A3U/w400-h301/ECG-MP-39a+Dynamic+ST+%252811-3.1-2021%2529-USE.png" width="400" /></span> —</a></span><span> </span></span></div><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span></b><b>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>39a (</b><i>4:50 minutes <b><u>Audio</u></b></i><b>)</b> — Reviews the concept of <b><i>Dynamic</i> ST-T Wave Changes (</b><i>and how this ECG finding can assist in determining if acute cardiac cath is indicated</i><b>)</b>.<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><div class="separator" style="clear: both;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropbox.com/s/haqaqaeus863uy4/z-ECG-Audio%20Pearl-46a%20Serial%20Tracings%20%2811-2.1-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1501" data-original-width="2048" height="294" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjGBpnry5zObW26LMvekXQoVv69JCSGETbgzWYCXjIB63xp2QcrIDh5e6Gysy7Z25ne2yXz_cV9m-VPec8OpmicSMufbbZliUz6kLUTF4c-HTG7qJAi91TWTmlS17cdZ_lPwdbALsHMak/w400-h294/ECG-MP-46a+Serial+ECGs+%252811-2.21-2021%2529-USE.png" width="400" /></span>—</a> <i><span style="font-family: arial; font-size: medium;"> </span></i></span></div><p style="text-align: start;"></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span></b><b>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>46a (</b><i>6:35 minutes </i><b><u><i>Audio</i></u>)</b> — Reviews <i>HOW</i> to <b><span style="color: red;">c</span>ompare <i><span style="color: red;">S</span>erial</i> <span style="color: red;">E</span>CGs (</b>ie, <i>Are you comparing "Apples with Apples" — <u>or</u> — with Oranges?</i><b>)</b>.</span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p></span></div><div><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropboxusercontent.com/s/tj2n20hmg0fuhj2/z-ECG%20Audio%20Pearl-10-OMI-Culprit%20%282-12.5-2021%29-USE-Faster.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1252" data-original-width="2048" height="245" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgqqr9rDjZmLTqgW7bhmsiYB9L0uhZ8WTpJh0mdAUANMCzcgIa40oZ2eDCeW5NgPxfHFqhS9hMjZv3Ud8_fo7hF2pjfdJxm4uSfiHhCdjUaywDThjhh48gWNZMUMnyMLqCfb8HkY9SIY30/w400-h245/MP-10+%2528193%2529+OMI-+Culprit+Artery-USE.png" width="400" /></span> —</a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="text-align: left;"><div style="display: inline; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span>CG <span style="color: red;">M</span>edia <span style="color: red;">P</span>EARL <span style="color: red;">#</span>10 (</b><i>10 minutes <u><b>Audio</b></u></i><b>)</b> — reviews the concept of why the term <b>“OMI” (</b> = <i><u>O</u>cclusion-based <u>MI</u></i><b>) </b>should <i><u>replace</u></i> the more familiar term STEMI — <u>and</u> — reviews the basics on how to <b><i>predict</i></b> the <b><i>"culprit"</i></b> <b>artery</b>.</span></div></span></div><p style="text-align: left;"></p></span></span></div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="font-family: arial; font-size: medium; text-align: left;"></span></span></p><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropboxusercontent.com/s/4ublcje6en3xvhv/z-ECG%20Audio%20Pearl-11%20Reperfusion%20%282-12.5-2021%29-USE-Faster.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1432" data-original-width="2048" height="280" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwAubBMD5ekmWf3JU7rJL_rSjod3oxr_S-N358ThxTg8uS4T5qwXgSniTBctjJ7vQ45lo8uBjPxsJX6Z0ar7FsKlYV2CIFdC2MnQV8BM_emnMYa_fJdiArLOTAV1c8ICdRyyM-TW_cvA0/w400-h280/MP-11+%2528194%2529-Has+Culprit+Reperfused-USE.png" width="400" /></span> —</a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="text-align: left;"><div style="display: inline; text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span><span style="font-style: italic;"><span style="font-style: normal;">CG</span> <span style="color: red;">M</span>edia</span><i> </i><span style="color: red;">P</span>EARL <span style="color: red;">#</span>11 (</b><span style="font-style: italic;">6 minutes <u>Audio</u></span><b>)</b><i> — </i>Reviews how to tell IF the <b>“culprit”</b> <b>(</b><i>ie,</i><b style="font-style: italic;"> </b><span style="font-style: italic;">acutely occluded</span><b>) artery</b> has<i> reperfused, </i>using clinical and ECG criteria<i>. </i></span></div></span></div></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial;"><div class="separator" style="clear: both;"><span style="font-family: arial; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVRkMlUeDRbwLNbZCp5oNBEh1NOdTWBA4go4pf9WMI9Rci3Pwedg5RmDQKno7zrNU-ZdYvIjCrrNKGxDa-egc0yVEolfXJWGSOf7VGttkE7jm9uCymL7xgKtzAdKWObExPdzYCZ3FVGAA/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgVRkMlUeDRbwLNbZCp5oNBEh1NOdTWBA4go4pf9WMI9Rci3Pwedg5RmDQKno7zrNU-ZdYvIjCrrNKGxDa-egc0yVEolfXJWGSOf7VGttkE7jm9uCymL7xgKtzAdKWObExPdzYCZ3FVGAA/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div><br /></div><div style="text-align: justify;"><div><div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div></div></div></div><div><br /></div></span></div></div></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div></div></div></div></span></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-79480054870293230982023-12-09T00:23:00.000-05:002023-12-09T00:23:02.764-05:00ECG Video Blog #407 (292): Why the Patient Died? <span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;"><div><span style="color: #050505;">======================================</span></div><div><span><span style="font-family: arial; font-size: medium;"><span style="color: #050505;"> </span><b style="color: #050505;"><a href="https://youtu.be/FFIzvdeLrR0" target="_blank">CLICK HERE</a></b><i style="color: #050505;"> — for a </i><u style="font-weight: bold;"><span style="color: red;">V</span><span style="color: #050505;">ideo</span></u><span style="color: #050505;"> presentation of this case! (22:3<i>0 min.</i>)</span></span></span></div><p class="MsoNormal" style="margin: 0in;"></p><ul><li><span style="color: #050505;">Below are slides used in my video presentation.</span></li><li><span style="color: #050505;">For full discussion of this case — <i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2022/03/ecg-blog-292-why-did-patient-die.html" target="_blank">ECG Blog #292</a> </b>—</span></li></ul><p></p><div><span style="color: #050505;">======================================</span></div><div><span style="color: #050505;"><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><br /></p></span></div></div><div style="text-align: justify;"><div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><div><span style="font-family: arial; font-size: medium;">The 2 ECGs shown in <b><u>Figure-1</u></b> were obtained from a man in his 30s — who presented to the ED (<i><u>E</u>mergency <u>D</u>epartment</i>) with <b><i>chest</i></b> <b>pain</b> that began several hours earlier. <b><u>ECG #2</u></b> was recorded 1 hour <i><u>after</u></i> <b>ECG #1</b>. Initial troponin was negative.</span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">Cardiac cath was advised — but the patient refused. Instead, he left the hospital — <i>only to be found <u>dead</u> at home 36 hours later</i>. </span></div><div><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">How would <i>YOU</i> interpret the serial ECGs shown in <u>Figure-1</u>?</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i><b>WHY did the patient die? </b></i></span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><span style="font-family: arial; font-size: medium;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEgiHZPVusSaeXxVN0BZ1pGSvikh9TE58IkzFiHrtH22fG1RFwfHn94iLklLkuk93_ud715cdM_aZ7fdBeH_cuzUv7p8c3sYnDNuihwx2URYLI3UQm8TAifOHsIbP8zV4JFyGymIB5ZCJxEzX_yiHHamZ2deBPZEcRvUuBL-JVJJQdExk79IHY3Nj_17=s3640" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2334" data-original-width="3640" height="256" src="https://blogger.googleusercontent.com/img/a/AVvXsEgiHZPVusSaeXxVN0BZ1pGSvikh9TE58IkzFiHrtH22fG1RFwfHn94iLklLkuk93_ud715cdM_aZ7fdBeH_cuzUv7p8c3sYnDNuihwx2URYLI3UQm8TAifOHsIbP8zV4JFyGymIB5ZCJxEzX_yiHHamZ2deBPZEcRvUuBL-JVJJQdExk79IHY3Nj_17=w400-h256" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b><u>Figure-1:</u></b> The 2 ECGs in today's case (<i>See text</i>).</span></td></tr></tbody></table><br style="text-align: left;" /></span></span></div><div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgRABt0WSYN4zMNcjzTAwN6Wf9w4G_dnmGacPcZmudNB3JxcWUmV8FJTEXyp59mxh-huyAAMzeCdoTZEgrgE1JLVYIHfFThe_gHuBP_CGwmGJLAvWkQEFcU5JaDuv7qAcI7W5de5kgxY29nBshpfCFPJ818Utdm6DJCHCDzEFNf2IF0pfeRuTUaLigXjZM/s3570/020-%20Figure%20ECGs-1,2-Hx,POLL%20(11-6.22-2023)-USE.png" style="margin-left: 1em; 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font-size: medium;">=======================</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">A</span>DDENDUM<span style="color: red;">:</span></u></b> Some <i>additional</i> material on ECG diagnosis of OMI.</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">=======================</span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><span><a href="https://dl.dropbox.com/s/53c2h2p37ld2y95/z-ECG%20Audio%20Pearl-39a%20Dynamic%20ST-T%20%2811-3.21-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1540" data-original-width="2048" height="301" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi46YyU9sfDJJXy3xrDieL__7t8YCL7_5jiUHOIgYuo5Lv8yyPlPlW2jka16OoA7UZlYLniBaaaBoeqPjAHhtXfP4qYybRknLHM4hAkP8mWk5NSMERKYY8jniE7l3bmrtI__Ab-NQp0A3U/w400-h301/ECG-MP-39a+Dynamic+ST+%252811-3.1-2021%2529-USE.png" width="400" /></span> —</a></span><span> </span></span></div><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span></b><b>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>39a (</b><i>4:50 minutes <b><u>Audio</u></b></i><b>)</b> — Reviews the concept of <b><i>Dynamic</i> ST-T Wave Changes (</b><i>and how this ECG finding can assist in determining if acute cardiac cath is indicated</i><b>)</b>.<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropbox.com/s/haqaqaeus863uy4/z-ECG-Audio%20Pearl-46a%20Serial%20Tracings%20%2811-2.1-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1501" data-original-width="2048" height="294" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjGBpnry5zObW26LMvekXQoVv69JCSGETbgzWYCXjIB63xp2QcrIDh5e6Gysy7Z25ne2yXz_cV9m-VPec8OpmicSMufbbZliUz6kLUTF4c-HTG7qJAi91TWTmlS17cdZ_lPwdbALsHMak/w400-h294/ECG-MP-46a+Serial+ECGs+%252811-2.21-2021%2529-USE.png" width="400" /></span>—</a> <i><span style="font-family: arial; font-size: medium;"> </span></i></span></div><p style="text-align: start;"></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><span style="color: red;">E</span></b><b>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>46a (</b><i>6:35 minutes </i><b><u><i>Audio</i></u>)</b> — Reviews <i>HOW</i> to <b><span style="color: red;">c</span>ompare <i><span style="color: red;">S</span>erial</i> <span style="color: red;">E</span>CGs (</b>ie, <i>Are you comparing "Apples with Apples" — <u>or</u> — with Oranges?</i><b>)</b>.</span></p></span></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhwWHfM6W3aICHDBq3XV1KBPFXWb4j_daZbiX9_JuSjIedIyiURw73R0thZsA12obcGM2qeFUAkJ8tBiR2kN5VPT5m8HSiIlB3aNqVeWcwo4pKZJoDDnVhDDv_8XjfW_eI5O58nPSoPytOkKE2DnH3sIYwPDYkmNNIAFQ2DH-_20E56Kh6vTVTVqtdE=s613" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/a/AVvXsEhwWHfM6W3aICHDBq3XV1KBPFXWb4j_daZbiX9_JuSjIedIyiURw73R0thZsA12obcGM2qeFUAkJ8tBiR2kN5VPT5m8HSiIlB3aNqVeWcwo4pKZJoDDnVhDDv_8XjfW_eI5O58nPSoPytOkKE2DnH3sIYwPDYkmNNIAFQ2DH-_20E56Kh6vTVTVqtdE=w400-h16" width="400" /></span></a></div></div><div style="text-align: justify;"><br /></div><div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><i><u>Related</u></i></b><b><u> ECG Blog Posts to <i>Today’s</i> Case: <o:p></o:p></u></b></span></p><p class="MsoNormal" style="margin: 0in;"></p><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i>Systematic</i></b> <b>Approach</b> to 12-lead ECG Interpretation.</span> </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-183-repolarization-variant.html" target="_blank">ECG Blog #183</a></b> — Reviews the concept of <b><i><span style="color: red;">d</span>e<span style="color: red;">W</span>inter</i> <span style="color: red;">T</span>-<span style="color: red;">W</span>aves (</b><i>with reproduction of the illustrative Figure from the original deWinter NEJM manuscript</i><b>)</b>.</span></span> </li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-222-39-are-there-dynamic-st-t.html" target="_blank">ECG Blog #222</a></b> — Reviews the concept of <b><i><u><span style="color: red;">D</span>ynamic</u></i> <span style="color: red;">S</span>T-<span style="color: red;">T</span> wave <span style="color: red;">c</span>hanges</b>, in the context of a detailed clinical case.</span> </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-260-repolarization-change.html" target="_blank">ECG Blog #260</a></b> — Reviews another case that illustrates the concept of <b><i>"dynamic"</i></b> <b>ST-T wave changes</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/04/ecg-blog-218-ecg-mp-35-what-is.html" target="_blank">ECG Blog #218</a></b> — Reviews <i>HOW</i> to define a <b><span style="color: red;">T</span> wave</b> as being <b><span style="color: red;">H</span>yperacute<span style="color: red;">?</span></b></span> </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/06/ecg-blog-230-46-are-there-serial-ecg.html" target="_blank">ECG Blog #230</a></b> — Reviews <i>HOW</i> to <b><span style="color: red;">c</span>ompare <i><span style="color: red;">S</span>erial</i> <span style="color: red;">E</span>CGs (</b>ie, <i>"Are you comparing Apples with Apples or Oranges?"</i><b>)</b>.</span> </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-193-ecg-mp-10-acute-omi.html" target="_blank">ECG Blog #193</a> </b>— Reviews the concept of why the term <b>“OMI” (</b> = <i><u>O</u>cclusion-based <u>MI</u></i><b>)</b> should <i><u>replace</u></i> the more familiar term STEMI — <u>and</u> — reviews the basics on how to <b><i>predict</i></b> the <b><i>"<u>culprit</u>" </i>artery</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><span style="color: #050505;"><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-194-ecg-mp-11-reperfusion-of.html" target="_blank">ECG Blog #194</a> </span></b><span style="color: #050505;">— Reviews how to tell IF the <b>“culprit” (</b>ie, <i>acutely occluded</i><b>)</b> artery has <i>reperfused</i> using clinical and ECG data.</span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="color: #050505;"><br /></span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2015/07/ecg-blog-115-early-repolarization.html" target="_blank">ECG Blog #115</a></b> — Shows an example of how drastically the ECG may change in <i>as little as</i> <b>8 minutes</b>.</span></li></ul><div><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">The <b><a href="http://hqmeded-ecg.blogspot.com/2019/01/a-patient-with-chest-pain-and-dynamic.html" target="_blank">January 9, 2019</a> post</b> in Dr. Smith's ECG Blog <b>(</b><i>Please scroll down to the <u>bottom</u> of the page to see </i><b><i>My Comment</i>)</b>. This case is remarkable for the <b><span style="color: red;">d</span>ynamic <span style="color: red;">S</span>T<span style="color: red;">-</span>T <span style="color: red;">w</span>ave <span style="color: red;">c</span>hanges</b> that are seen. It's helpful to appreciate: <b>i<span style="color: red;">)</span> </b>That acute ischemia/infarction is <i><u>not</u></i> the only potential cause of such changes (<i>cardiac cath was normal</i>); <b>ii<span style="color: red;">)</span></b> That changes in heart rate, frontal plane axis <i>and/or</i> patient positioning can <i><u>not</u></i> always explain such changes; <u>and</u>, <b>iii<span style="color: red;">)</span></b> That entities such as repolariztion variants, LVH <i>and/or</i> acute myopericarditis may <i><u>all</u></i> contribute on occasion to produce an evolution of challenging <i>dynamic</i> ST-T wave changes on serial ECGs.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">The <b><a href="http://hqmeded-ecg.blogspot.com/2020/08/dynamic-st-change-in-mid-50s-man-with.html" target="_blank">August 22, 2020</a> post</b> in Dr. Smith's ECG Blog — which illustrates another case of <b><i>dynamic</i></b> <b>ST-T wave changes</b> that resulted from a <b><i>repolarization</i></b> <b>variant</b>. </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">The <b><a href="https://hqmeded-ecg.blogspot.com/2018/07/an-athletic-30-something-woman-with.html" target="_blank">July 31, 2018</a> post</b> in Dr. Smith's ECG Blog <b>(</b><i>Please <b>scroll down</b> to the <b><u>bottom</u></b></i> <i>of the page to see </i><b><i>My Comment</i>)</b>. This case provides an excellent example of <b><i><span style="color: red;">d</span>ynamic</i></b> <b><span style="color: red;">S</span>T-<span style="color: red;">T</span> wave <span style="color: red;">c</span>hanges</b> on serial tracings (<i>that I illustrate in My Comment</i>) in a patient with an <b>ongoing <i>acutely</i> evolving infarction</b>.</span></li></ul></div></span></div><div style="text-align: justify;"><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhwWHfM6W3aICHDBq3XV1KBPFXWb4j_daZbiX9_JuSjIedIyiURw73R0thZsA12obcGM2qeFUAkJ8tBiR2kN5VPT5m8HSiIlB3aNqVeWcwo4pKZJoDDnVhDDv_8XjfW_eI5O58nPSoPytOkKE2DnH3sIYwPDYkmNNIAFQ2DH-_20E56Kh6vTVTVqtdE=s613" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/a/AVvXsEhwWHfM6W3aICHDBq3XV1KBPFXWb4j_daZbiX9_JuSjIedIyiURw73R0thZsA12obcGM2qeFUAkJ8tBiR2kN5VPT5m8HSiIlB3aNqVeWcwo4pKZJoDDnVhDDv_8XjfW_eI5O58nPSoPytOkKE2DnH3sIYwPDYkmNNIAFQ2DH-_20E56Kh6vTVTVqtdE=w400-h16" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div><br /></div></div></div></div></div></div></div><div><div style="font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="font-family: -webkit-standard;"><br /></div><div style="font-family: -webkit-standard; text-align: left;"><span style="font-family: arial;"><div style="text-align: justify;"><br /></div></span></div></div></div></span>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com1tag:blogger.com,1999:blog-3364570834099131201.post-81677039707378839392023-12-02T00:25:00.001-05:002023-12-03T20:48:18.921-05:00ECG Video Blog #406 — To Do Additional Leads? <span style="font-family: arial; font-size: medium;"><br /></span><div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><div><span style="color: #050505;">======================================</span></div><div><span><span style="font-family: arial; font-size: medium;"><span style="color: #050505;"> </span><b style="color: #050505;"><a href="https://youtu.be/_QvZ9l_FDXs" target="_blank">CLICK HERE</a></b><i style="color: #050505;"> — for a </i><u style="font-weight: bold;"><span style="color: red;">V</span><span style="color: #050505;">ideo</span></u><span style="color: #050505;"> presentation of this case! (<i>19:40 min.</i>)</span></span></span></div><p class="MsoNormal" style="margin: 0in;"></p><ul><li><span style="color: #050505;">Below are slides used in my video presentation.</span></li><li><span style="color: #050505;">For full discussion of this case — <i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2022/12/ecg-blog-351-posterior-leads.html" target="_blank">ECG Blog #351</a> </b>—</span></li></ul><p></p><div><span style="color: #050505;">======================================</span></div><div><span style="color: #050505;"><br /></span></div><div><span style="color: #050505;"><br /></span></div><div><span style="color: #050505;"><span style="caret-color: rgb(0, 0, 0); color: black; font-family: arial; font-size: medium; text-align: left;"><div style="text-align: justify;">The ECG in <b><u>Figure-1</u></b> — was obtained from a previously healthy older man who contacted EMS (<i><u>E</u>mergency <u>M</u>edical <u>S</u>ervices</i>) because of <b><i>"chest tightness" </i></b>that began ~1 hour earlier. <i>Given this history:</i></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>QUESTIONS:</u></b> </div><div style="text-align: justify;"><ul><li><i>How would YOU interpret</i> the ECG in <u>Figure-1</u>?</li><li>Should you activate the cath lab ?</li></ul></div></span><div style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; text-align: left;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjYl58OoL8xcovgDxGVpkT0mM7eHelFmVBbUEaRnzx1vsMidXdZzPDJTEBY1CvfjYrZFsLmnD3YYC3Wu3w69DmQG2w8PRf67pQykOl3lyqy9zJglLPDrHnYQJpaM1AjJDkH2jtsUGnIg6CFuC2V2fa1eZ63P9q4WsJfFsMMclkiIzBgiAbjHDewWbXJ/s3792/Figure-1%20%20ECG-1%20(12-9.21-2022)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1396" data-original-width="3792" height="148" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjYl58OoL8xcovgDxGVpkT0mM7eHelFmVBbUEaRnzx1vsMidXdZzPDJTEBY1CvfjYrZFsLmnD3YYC3Wu3w69DmQG2w8PRf67pQykOl3lyqy9zJglLPDrHnYQJpaM1AjJDkH2jtsUGnIg6CFuC2V2fa1eZ63P9q4WsJfFsMMclkiIzBgiAbjHDewWbXJ/w400-h148/Figure-1%20%20ECG-1%20(12-9.21-2022)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><span><b style="text-align: start;"><u>Figure-1:</u> </b><span style="text-align: start;">The initial ECG in today's case — obtained by EMS at the scene, from an older man with ~1-hour of chest "tightness". </span></span><b>(</b><i>To improve visualization — I've digitized the original ECG using</i><span> </span><b><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span>.</span></span></td></tr></tbody></table></div></span></div><div><span style="color: #050505;"><br /></span></div></span></div><div style="text-align: justify;"><div><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjFN3comrVy5e1K6xhFvgzyUf9RxXk8fmB1a7YlT7PIOIgcmh6M2psyOcO_JGv3MVrfZcR3SIZpaeS1tg8HH8aEUHq90-W40RwXupEOjX1pz4lYV4pPoKVil2JHTPZabBVn7kAohbuokA3iz2Tr4TOk2SSR6yeczBQdK7nVJJ1S4TWGzRqqmfuCxtX5pBs/s3694/02-%20Figure-2%20My%20POLL%20(10-29.1-2023).png" style="margin-left: 1em; 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text-align: center;"><span style="font-family: arial; margin-left: auto; margin-right: auto;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkK-CI0tNg9si9WlGL0hEgd9TMBDJSMhJic0qBjw5ZB6SIYsl6pB_0RLF6rPCw7cWABoT_ferdPbfp8CAgbhCMp0R3ODWxbvAjzPGad8wqoAN3lIZ1XtdH3GDKxnsX4AWrfwCXWxvSH8g/s2048/Figure-3+ECG+Findings+to+Look+For+%25282-10.1-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1651" data-original-width="2048" height="323" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgkK-CI0tNg9si9WlGL0hEgd9TMBDJSMhJic0qBjw5ZB6SIYsl6pB_0RLF6rPCw7cWABoT_ferdPbfp8CAgbhCMp0R3ODWxbvAjzPGad8wqoAN3lIZ1XtdH3GDKxnsX4AWrfwCXWxvSH8g/w400-h323/Figure-3+ECG+Findings+to+Look+For+%25282-10.1-2021%2529-USE.png" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #333333;">Figure-4:</span></u></b><span style="color: #333333; text-align: justify;"> ECG findings to look for <b>when your patient</b> with <i>new-onset</i> cardiac symptoms <b>does <i><u>not</u></i> manifest <i>STEMI-criteria</i> ST elevation</b> on ECG. For more on this subject — <i>SEE the</i> <b><a href="http://hqmeded-ecg.blogspot.com/2020/08/omi-manifesto-lecture-in-20-minutes-via.html" target="_blank">September 3, 2020</a> post</b> in Dr. Smith’s ECG Blog with 20-minute video talk by Dr. Meyers on <b><i>The </i></b></span><b style="text-align: justify;"><i><span style="color: red;">O</span></i></b><b style="text-align: justify;"><i><span style="color: #333333;">MI </span></i></b><b style="text-align: justify;"><i><span style="color: red;">M</span></i></b><b style="text-align: justify;"><i><span style="color: #333333;">anifesto</span></i></b><span style="color: #333333; text-align: justify;">. For my clarifying Figure illustrating <b>T-QRS-D</b> (<i>2nd bullet</i>) — See <i><u>My</u> <u>Comment</u></i> at the <u>bottom</u> of the page in Dr. Smith’s <b><a href="http://hqmeded-ecg.blogspot.com/2019/11/a-50-something-with-left-shoulder-pain.html" target="_blank">November 14, 2019</a> post</b>.</span></span></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgxG8-HFBld58RBIti8tuEaIMmOw9vFhEhCSSvWFrjve4KgJeWVh5yVp4zOQrs8YKoJk0XUP79ABpId7w9dOtWa7kl5oxgyp8nE_ToESteaqFsY3yLeHFxmi6essGyMPz0YDTgkQvP3lPHOlcgAgq_AUIgqH6fppuf_HyogbGIhicuP43r78fTFO-Y2mc0/s3670/03-%20Figure-1%20ECG-1,%20Systematic%20(10-29.21-2023)-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2624" data-original-width="3670" height="286" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgxG8-HFBld58RBIti8tuEaIMmOw9vFhEhCSSvWFrjve4KgJeWVh5yVp4zOQrs8YKoJk0XUP79ABpId7w9dOtWa7kl5oxgyp8nE_ToESteaqFsY3yLeHFxmi6essGyMPz0YDTgkQvP3lPHOlcgAgq_AUIgqH6fppuf_HyogbGIhicuP43r78fTFO-Y2mc0/w400-h286/03-%20Figure-1%20ECG-1,%20Systematic%20(10-29.21-2023)-USE.png" width="400" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><div><br /></div><div><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyYuV8ma8eFikikvqrzuEBSsT0BDRfpuWVLxkUWQqpZ0AJUdoVklr7HzxZAxjh_QrfCtRRgP0Lj7FaAL57JiA9-kAPqlrU7hCOU5KQHAXqFpFoLVG2bU5xd9FGO9_7teSacnzu_TpNjuZdNWh3WtOF3Ba8C5P_qEoiI2B2aMZdVgNEZj1pCzDGZvWUdps/s2664/04%20-%20Figure-4%20Blog%20205%20for%20System%20(10-29.1-2023)-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="734" data-original-width="2664" height="110" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgyYuV8ma8eFikikvqrzuEBSsT0BDRfpuWVLxkUWQqpZ0AJUdoVklr7HzxZAxjh_QrfCtRRgP0Lj7FaAL57JiA9-kAPqlrU7hCOU5KQHAXqFpFoLVG2bU5xd9FGO9_7teSacnzu_TpNjuZdNWh3WtOF3Ba8C5P_qEoiI2B2aMZdVgNEZj1pCzDGZvWUdps/w400-h110/04%20-%20Figure-4%20Blog%20205%20for%20System%20(10-29.1-2023)-USE.png" width="400" /></a></div><p></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;">============================</span></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><b>ECG Blog #205</b> = The <i>Systematic </i>Approach I favor ...</span></p><p class="MsoNormal" style="margin: 0in;"></p><ul><li>The <b><i>"formula"</i></b> = https://tinyurl.com/KG-Blog-2XX</li><li><b><u>LINK</u></b> for Blog #205 = <a href="https://tinyurl.com/KG-Blog-205">https://tinyurl.com/KG-Blog-205</a> -</li></ul><p></p><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;">============================</span></p></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><br /></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: -webkit-standard; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjb9LLwmKGiJQcaBAaeuHYiGkttYYwxXc_abAcjRx6xLpbIxU-QZXA04weRIL7_xyUF4F3wO8fBZex9vINFulSSeTRLajCUw-Mz3h5yItPITiiGqXEPgzH8xIS253XeNBmdW8yuruXsi3g/s2048/Figure-2+System+Approach-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1542" data-original-width="2048" height="301" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjb9LLwmKGiJQcaBAaeuHYiGkttYYwxXc_abAcjRx6xLpbIxU-QZXA04weRIL7_xyUF4F3wO8fBZex9vINFulSSeTRLajCUw-Mz3h5yItPITiiGqXEPgzH8xIS253XeNBmdW8yuruXsi3g/w400-h301/Figure-2+System+Approach-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="text-align: justify;"><span style="color: #050505;"> The </span><i style="color: #050505;">Systematic</i><span style="color: #050505;"> Approach that I favor. Review of the </span><b style="color: #050505;"><i>first</i></b><span style="color: #050505;"> </span><b style="color: #050505;">4 parameters</b><span style="color: #050505;"> in </span><i style="color: #050505;">Descriptive</i><span style="color: #050505;"> Analysis </span><b style="color: #050505;">(</b><i style="color: #050505;">Rate; Rhythm; Intervals; Axis</i><b style="color: #050505;">)</b><span style="color: #050505;">. </span><b><u><span style="color: red;">N</span><span style="color: #050505;">OTE</span><span style="color: red;">:</span></u></b><span style="color: #050505;"> IF the QRS complex is wide — then </span><b><i style="color: #050505;">STOP</i><span style="color: #050505;"> and find out </span><i style="color: #050505;">WHY</i></b><span style="color: #050505;"><b> the QRS is wide</b> </span><i style="color: #050505;"><u>before</u></i><span style="color: #050505;"> proceding to assessment of Axis, Chamber Enlargement and QRST Changes. This is because IF the QRS is wide because of BBB (<i><u>B</u>undle <u>B</u>ranch <u>B</u>lock</i>) — criteria for axis, hypertrophy, and ST-T wave changes will be different when there is BBB or IVCD! To emphasize, <u>IF</u> the QRS is wide — </span><b style="color: #050505;"><i>this is the ONE time that I depart from the sequence</i></b><span style="color: #050505;"> in </span><u style="color: #050505;">Figures-2</u><span style="color: #050505;"> and -</span><u style="color: #050505;">3</u> <b style="color: #050505;">(P.S. </b><span style="color: #050505;">IF the QRS is wide — </span><i style="color: #050505;">Make sure that the rhythm is <u>not</u> VT. If the rhythm is sinus</i><span style="color: #050505;"> — </span><b style="color: #050505;"><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-204-ecg-mp-22-bundle-branch.html" target="_blank">ECG Blog #204</a></b> <i style="color: #050505;">reviews how to determine if RBBB, LBBB or IVCD is present</i><b style="color: #050505;">)</b><span style="color: #050505;">.</span></span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="margin: 0in;"><br /></p><p class="MsoNormal" style="margin: 0in;"><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMlZi3NthjawObh-noFJFryTC-T_VnK3FtV6IuVK3KrMMEgTUMk3NMuHvKDTvqpHWIXkKUpNSoj8cRpSG1p2QEYiAsWgWp9T3sQq_CeWQJv4YVainmLyb2tSdnrz5x9gdVYzZbJw_OqoHsxtGFpBtWgV-h5Ff2IadL74jtJ4pnAt3L12TUA0C-hRJ16OU/s3434/06%20-%20Figure%20XXX-%20IF%20the%20QRS%20is%20Wide%20(10-29.1-2023)-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1676" data-original-width="3434" height="195" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMlZi3NthjawObh-noFJFryTC-T_VnK3FtV6IuVK3KrMMEgTUMk3NMuHvKDTvqpHWIXkKUpNSoj8cRpSG1p2QEYiAsWgWp9T3sQq_CeWQJv4YVainmLyb2tSdnrz5x9gdVYzZbJw_OqoHsxtGFpBtWgV-h5Ff2IadL74jtJ4pnAt3L12TUA0C-hRJ16OU/w400-h195/06%20-%20Figure%20XXX-%20IF%20the%20QRS%20is%20Wide%20(10-29.1-2023)-USE.png" width="400" /></a></div><br /><p class="MsoNormal" style="margin: 0in;"><br /></p><p class="MsoNormal" style="margin: 0in;"><br /></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="font-family: -webkit-standard; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_90o1UXbOnX6K3Tk-wP7CK-q3s0OSnFiILGUQX904SF7BrKnD0H-B0bhrPldytTAoyYtmFha2vbGzCXAXpgfLTrX16BNGKkf-Lccw03SyBITOYXFDSrT5qQvbudbXIGg6Zav3eR2dEhs/s2048/Figure-3+Syst+Approach+%2528cont%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1539" data-original-width="2048" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj_90o1UXbOnX6K3Tk-wP7CK-q3s0OSnFiILGUQX904SF7BrKnD0H-B0bhrPldytTAoyYtmFha2vbGzCXAXpgfLTrX16BNGKkf-Lccw03SyBITOYXFDSrT5qQvbudbXIGg6Zav3eR2dEhs/w400-h300/Figure-3+Syst+Approach+%2528cont%2529-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; text-align: justify;"> The <i>Systematic</i> Approach that I favor (<i>Continued</i>). Review of the <b><i>last</i></b> <b>2 parameters</b> in <i>Descriptive </i>Analysis <b>(</b><i>Chamber Enlargement; Looking for Q-R-S-T Changes</i><b>)</b> — and then formulating your <i>Clinical </i>Impression.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div><span style="font-family: arial; font-size: medium; text-align: left;"><span style="text-align: justify;">=======================================</span></span></div><div><span style="font-family: arial; font-size: medium; text-align: left;"><span style="text-align: justify;"><br /></span></span></div><div style="text-align: right;"><span style="font-family: arial; font-size: medium; text-align: left;"><span style="text-align: justify;"><br /></span></span></div><div style="text-align: center;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEguZAN-5RMUf_j2emRvOyNR7ZOD74Xd2SCOl-o2Gq0uB8PDW2HP-hGghIEJMLjQFRBlxGF5Th_g3O4bvbRZfo2zCVql7WQmojhfUKHS2NtW6rjUKdGe8lQJPtsfcxXcOxw3-P2nLhzIyij_N13XLNHMqV3vJUw7jmEor5caiKRMwM4ItwgdeUu6V2WYAyM/s3230/003.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1408" data-original-width="3230" height="174" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEguZAN-5RMUf_j2emRvOyNR7ZOD74Xd2SCOl-o2Gq0uB8PDW2HP-hGghIEJMLjQFRBlxGF5Th_g3O4bvbRZfo2zCVql7WQmojhfUKHS2NtW6rjUKdGe8lQJPtsfcxXcOxw3-P2nLhzIyij_N13XLNHMqV3vJUw7jmEor5caiKRMwM4ItwgdeUu6V2WYAyM/w400-h174/003.png" width="400" /></a></div><br /><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium; text-align: left;"><span style="font-family: arial; font-size: medium; margin-left: auto; margin-right: auto;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-U5Gu68yy3F4Zb2-4dXY9vXLe2MKGxQ521DJQjU08pFyzqzboSPlHv-Jv4XzJppFJKzZOXGQF9ppWaRX98MD-PmPt2sf_LhzJjVPeU0naA4asMAQtTMnwk7FZxHIauRMEtzXX716DQrVWgkIkbe6TT32QMEkity4ykS11rSGJ_TjxpfsBT8skzu2M/s3778/Figure-2%20%20ECG-1%20Mirror%20(12-9.21-2022)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1374" data-original-width="3778" height="145" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg-U5Gu68yy3F4Zb2-4dXY9vXLe2MKGxQ521DJQjU08pFyzqzboSPlHv-Jv4XzJppFJKzZOXGQF9ppWaRX98MD-PmPt2sf_LhzJjVPeU0naA4asMAQtTMnwk7FZxHIauRMEtzXX716DQrVWgkIkbe6TT32QMEkity4ykS11rSGJ_TjxpfsBT8skzu2M/w400-h145/Figure-2%20%20ECG-1%20Mirror%20(12-9.21-2022)-USE.png" width="400" /></a></span></span></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium; text-align: left;"><span style="font-size: medium;"><span style="font-family: arial;"><b><u>Figure:</u> </b></span><span style="font-family: arial; text-align: justify;">I've added the <i>mirror-image</i> of <b>leads V3</b> and <b>V4</b> to today's tracing — to illustrate how the <i>initial</i> ECG shows a <b><span style="color: red;">p</span>ositive <i>"<u><span style="color: red;">M</span>irror</u>"</i> <span style="color: red;">T</span>est </b>suggestive of <b>acute <i><u>posterior</u></i> OMI</b>.</span></span></span></div><div><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div><span style="font-family: arial; font-size: medium; text-align: left;"><br /></span></div><div style="text-align: center;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhI9AKdMDTBB7LvlZq20jomvUIA1SJv0VSBnkjIvUYKa9bBC4DirWSdBj1Y2BVgI7nhp-bbvzWHZ0VzR1LAJ51WhUpywvcTJU6Y3zTxCf68tSpQZfJH7nspZc12rfUt3eDoKGqYnLzlFdPvNZOWcpIGF-1TnBiF6QJftIka1UqiV4Jp32eE1ElnmuDXg30/s3120/004.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2334" data-original-width="3120" height="299" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhI9AKdMDTBB7LvlZq20jomvUIA1SJv0VSBnkjIvUYKa9bBC4DirWSdBj1Y2BVgI7nhp-bbvzWHZ0VzR1LAJ51WhUpywvcTJU6Y3zTxCf68tSpQZfJH7nspZc12rfUt3eDoKGqYnLzlFdPvNZOWcpIGF-1TnBiF6QJftIka1UqiV4Jp32eE1ElnmuDXg30/w400-h299/004.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: justify;"><span style="font-family: arial; font-size: medium; text-align: left;"><b><u>Figure:</u> </b><span>The repeat ECG.</span></span></td></tr></tbody></table><div style="text-align: center;"><br /></div><div style="text-align: center;"><br /></div><div style="text-align: center;"><br /></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbCfxAqW-FNr1VAG6U2X46XUBWcx9_Da6vRAXo2F9cU2p34XMsFnVhZ1s-9Eqb7XN6aKNv4fCdu-UoTugIWK8LKY9Lob7yFlnX_G2JhP8BrypSgoHP_2nDNLo7U-EB4YmBZUj73I34nSHqYQ7ZEE_tqCu3SBIPruLsBET0nBRIIqO0CzFDLNrSI-nefKs/s3192/006.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1726" data-original-width="3192" height="216" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbCfxAqW-FNr1VAG6U2X46XUBWcx9_Da6vRAXo2F9cU2p34XMsFnVhZ1s-9Eqb7XN6aKNv4fCdu-UoTugIWK8LKY9Lob7yFlnX_G2JhP8BrypSgoHP_2nDNLo7U-EB4YmBZUj73I34nSHqYQ7ZEE_tqCu3SBIPruLsBET0nBRIIqO0CzFDLNrSI-nefKs/w400-h216/006.png" width="400" /></a></div><div style="text-align: center;"><br /></div><div style="text-align: center;"><br /></div><div style="text-align: center;"><br /></div><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhANYUSR6xpW-bp-_Nxxswk76EsKjgHH8O0HCta85z1rEAjyIFotxK6G3zGFIX-RGbjrKFeyuFN9WKMqH0e3kyCzDJpUuZxzXzNpEXOkOIvCb9Bd7KxVlTwq0rv_EOjFVYbVvtLBAVAhhM8D13qmmHQjKdIinsPfzJVohEi4ZlTLeAybWwEaN8HTcT8K_Y/s2968/005.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2188" data-original-width="2968" height="295" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhANYUSR6xpW-bp-_Nxxswk76EsKjgHH8O0HCta85z1rEAjyIFotxK6G3zGFIX-RGbjrKFeyuFN9WKMqH0e3kyCzDJpUuZxzXzNpEXOkOIvCb9Bd7KxVlTwq0rv_EOjFVYbVvtLBAVAhhM8D13qmmHQjKdIinsPfzJVohEi4ZlTLeAybWwEaN8HTcT8K_Y/w400-h295/005.png" width="400" /></a></div><br /></div><div><span style="font-family: arial; font-size: medium; text-align: left;"><span style="text-align: justify;"><br /></span></span></div><div><br /></div><div><div style="font-family: -webkit-standard; text-align: left;"><p class="MsoNormal" style="font-family: arial; margin: 0in; text-align: justify;"><span style="color: #333333;">===============================</span></p><p class="MsoNormal" style="font-family: arial; margin: 0in; text-align: justify;"><span style="color: #333333;"><br /></span></p><div style="text-align: justify;"><div style="font-family: arial;"><span style="font-family: arial;"><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></div><div><ul style="font-family: arial;"><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span style="color: red;">S</span>ystematic</i></b> <b><span style="color: red;">A</span>pproach</b> to 12-lead ECG Interpretation.</li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-193-ecg-mp-10-acute-omi.html" target="_blank">ECG Blog #193</a></b> — illustrates use of the <b><i><span style="color: red;">M</span>irror</i></b> <b><span style="color: red;">T</span>est</b> to facilitate recognition of <b>acute <i>Posterior</i> MI</b>. This blog post reviews the basics for <i><u>predicting</u></i> the <b><i>"<span style="color: red;"><span>C</span></span>ulprit"</i></b> <b><span style="color: red;">A</span>rtery (</b><i>as well as reviewing why the term <b>"STEMI"</b> — should replaced by "<b>OMI"</b> = <u>O</u>cclusion-based <u>MI</u></i><b>)</b>.</span></li><li style="text-align: justify;"><span><br /></span></li><li style="text-align: justify;"><span><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2022/02/ecg-blog-285-wider-irregular-rhythm.html" target="_blank">ECG Blog #285</a></b> — </span><span style="font-family: arial;">for another example of <b>acute Posterior MI (</b><i>with <u>positive</u> </i><b><i>Mirror </i>Test)</b>.</span></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/08/ecg-blog-246-60-what-is-mirror-test.html" target="_blank">ECG Blog #246</a></b> — for another example of <b>acute Posterior MI (</b><i>with <u>positive</u> </i><b><i>Mirror</i> Test)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2013/12/ecg-interpretation-review-80-acute.html" target="_blank">ECG Blog #80</a></b> — reviews prediction of the "culprit" artery (<i>and provides another case illustrating the</i> <b><i><span>M</span>irror </i></b><b><span>T</span>est</b> <i>for diagnosis of</i> <b>acute <i>Posterior</i> MI</b>).</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2022/07/ecg-blog-317-80yo-man-cp-culprit.html" target="_blank">ECG Blog #317</a></b> — reviews another case regarding <b>use (</b><i>or not</i><b>) of Posterior Leads</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-184-audio-pearl-2-magical-lead.html" target="_blank">ECG Blog #184</a></b> — illustrates the <b><i>"magical"</i></b> <b>mirror-image opposite relationship</b> with acute ischemia between <b>lead III</b> <u>and</u> <b>lead aVL (</b><i>featured in Audio Pearl #2 in this blog post</i><b>)</b>. </span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2019/07/ecg-blog-167-reciprocal-omi-normal.html" target="_blank">ECG Blog #167</a></b> — another case of the <b><i>"magical"</i> mirror-image opposite relationship</b> between <b>lead III</b> <u>and</u> <b>lead aVL </b>that confirmed acute OMI.</span></li><li style="text-align: justify;"><span style="font-family: arial;"> </span></li><li style="text-align: justify;"><span style="font-family: arial;"><span>The <b><a href="https://hqmeded-ecg.blogspot.com/2019/02/how-much-time-are-you-willing-to-wait.html" target="_blank">February 16, 2019</a> post</b> in Dr. Smith's ECG Blog — My Comment (<i>at the bottom of the page</i>) emphasizes utility of the <b><i><span>M</span>irror</i></b> <b><span>T</span>est</b> for diagnosis of <b>acute <i>Posterior</i> MI</b>.</span> </span></li><li style="text-align: justify;"><span style="font-family: arial;"><span>Diagnosis of an <b>OMI</b> from the <i>initial</i> ECG — <u style="font-style: italic;">Serial</u> tracings with <b><i>spontaneous</i></b> <b>reperfusion</b> — then reocclusion! —</span> See <i>My Comment</i> at the bottom of the page in the <b><a href="http://hqmeded-ecg.blogspot.com/2020/10/dynamic-st-elevation.html" target="_blank">October 14, 2020</a></b> <b>post</b> on Dr. Smith's ECG Blog.</span></li><li style="text-align: justify;"><span style="font-family: arial;">Acute OMI that <i>wasn’t</i> accepted by the Attending — See <i>My Comment</i> at the bottom of the page in the <b><a href="http://hqmeded-ecg.blogspot.com/2020/11/the-resident-made-diagnosis-immediately.html" target="_blank">November 21, 2020</a> post</b> on Dr. Smith’s ECG Blog.</span></li><li style="text-align: justify;"><span style="font-family: arial;">Another <i><u>overlooked</u></i> OMI <b>(</b><i>Cardiologist limited by STEMI Definition — OMI evident by <b>Mirror Test</b></i><b>)</b> — See <i>My Comment</i> at the bottom of the page in the <b><a href="https://hqmeded-ecg.blogspot.com/2020/09/interventionalist-at-receiving-hospital.html" target="_blank">September 21, 2020</a> post</b> on Dr. Smith’s ECG Blog.</span></li><li style="text-align: justify;"><span style="font-family: arial;">Recognizing <b><i>hyperacute</i></b> <b>T waves</b> — patterns of leads — an <b>OMI (</b><i>though <u>not</u> a STEMI</i><b>)</b> — See <i>My Comment</i> at the bottom of the page in the <b><a href="http://hqmeded-ecg.blogspot.com/2020/11/this-skill-can-be-taught-and-learned.html" target="_blank">November 8, 2020</a> post</b> on Dr. Smith's ECG Blog.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-271-79-what-is-st-segment.html" target="_blank">ECG Blog #271</a></b> — Reviews determination of the ST segment baseline <b>(</b><i>with discussion of the entity o</i></span><i>f the entity of </i><b><i><span style="color: red;">d</span>iffuse <span style="color: red;">S</span>ubendocardial</i> <span style="color: red;">I</span>schemia)</b>.</li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-266-74-dewinter-t-waves-or.html" target="_blank">ECG Blog #266</a></b> — Reviews distinction between <b><i><span style="color: red;">P</span>osterior</i> <span style="color: red;">M</span>I</b> <i><u>vs</u></i> <b><i>de<span style="color: red;">W</span>inter</i> T waves </b></span></span><span style="font-family: arial;"><b>(</b><i>with</i></span><i> anterior terminal T wave positivity reflecting <b>"<span>R</span>eperfusion"</b></i><span style="font-family: arial;"> </span><b><span>T</span>-<span>w</span>aves)</b><span style="font-family: arial;">.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/10/ecg-blog-258-mp-70-how-to-date-mi.html" target="_blank">ECG Blog #258</a></b> — How to <b><i>"<span style="color: red;">D</span>ate"</i></b> an <b><span style="color: red;">I</span>nfarction</b> based on the <i>initial</i> ECG.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2022/03/ecg-blog-294-one-hour-later.html" target="_blank">ECG Blog #294</a></b> — Reviews how to tell <b><i>IF the "culprit" artery has reperfused</i></b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/06/ecg-blog-230-46-are-there-serial-ecg.html" target="_blank">ECG Blog #230</a></b> — Reviews how to <b><i>compare</i></b> <b>Serial</b> <b>ECGs</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2015/07/ecg-blog-115-early-repolarization.html" target="_blank">ECG Blog #115</a></b> — Shows how dramatic ST-T changes can occur in as short as an 8-minute period.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-268-76-mobitz-i-vs-complete-av.html" target="_blank">ECG Blog #268</a></b> — Shows an example of <b><i>reperfusion</i></b> <b>T waves</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-190-ecg-mp-7-where-is-acute.html" target="_blank">ECG Blog #190</a></b> — How to diagnose <b><i>acute</i> RV MI (</b><i>and use of right-sided leads</i><b>)</b>.</span></li></ul><div style="font-family: arial;"><br /></div></div></div></div><p class="MsoNormal" style="text-align: left;"><span style="font-family: arial;"></span></p><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhcUanPtyekRxG_NN3M6G7ixBWDiaFwP9HSTmmxsiAGLgKFyGGIePOLicsrDGS_HrTpJuFvbsUgWw_X6ZXKehXoAeVAyPHHXStk2lmG9uzuY33nE1KZQCLDvOH1VKIkbTzKmck2XR3I6_wmONnxXQmAen5uT-Ez0rJCH23wswN1g0uETqzQQugv30VE=s613" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/a/AVvXsEhcUanPtyekRxG_NN3M6G7ixBWDiaFwP9HSTmmxsiAGLgKFyGGIePOLicsrDGS_HrTpJuFvbsUgWw_X6ZXKehXoAeVAyPHHXStk2lmG9uzuY33nE1KZQCLDvOH1VKIkbTzKmck2XR3I6_wmONnxXQmAen5uT-Ez0rJCH23wswN1g0uETqzQQugv30VE=w400-h16" width="400" /></a></span></div></div></div><div style="text-align: right;"><br /></div><div style="text-align: right;"><span style="font-family: arial; font-size: medium; text-align: left;"><span style="text-align: justify;"><br /></span></span></div></span></div><div><div><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: justify;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-6709342069447851202023-11-25T04:11:00.002-05:002023-12-03T20:47:16.567-05:00ECG Video Blog #405 — Is AV Block Complete (vs AV Dissociation)<div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div><span style="color: #050505;">======================================</span></div><div><span><span style="font-family: arial; font-size: medium;"><span style="color: #050505;"> </span><b style="color: #050505;"><a href="https://youtu.be/k0RMgRYP0Zk" target="_blank">CLICK HERE</a></b><i style="color: #050505;"> — for a </i><u style="font-weight: bold;"><span style="color: red;">V</span><span style="color: #050505;">ideo</span></u><span style="color: #050505;"> presentation of this case! (<i>19:40 min.</i>)</span></span></span></div><p class="MsoNormal" style="margin: 0in;"></p><ul><li><span style="color: #050505;">Below are slides used in my video presentation.</span></li><li><span style="color: #050505;">For full discussion of this case — <i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-191-ecg-mp-8-is-av-block.html" target="_blank">ECG Blog #191</a> </b>—</span></li></ul><p></p><div><span style="color: #050505;">======================================</span></div><div><br /></div><div><br /></div></div></span><div><span style="font-size: medium;"><span style="background-color: white; white-space: pre-wrap;"><div style="text-align: justify;"><p class="MsoNormal" style="margin: 0in;"><span style="font-family: arial; font-size: medium;">The 2-lead rhythm strip shown in <b><u>Figure-1</u></b> was obtained from an elderly woman who presented to the ED following a syncopal episode. On the basis of this rhythm strip — she was diagnosed as being in <b><i>complete</i></b> <b>AV Block</b>.<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in;"></p><p class="MsoNormal" style="margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"></span></span></p><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><u><span face="Arial, sans-serif">Question #1</span></u><span face="Arial, sans-serif">: <i>Is there</i> <b>AV Dissociation </b>in <u>Figure-1</u><b>?</b></span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><u><span face="Arial, sans-serif">Question #2</span></u><span face="Arial, sans-serif">: Do <i>YOU</i> agree that the rhythm shown in this figure represents <b><u>complete</u> (</b> = <i>3rd-degree</i><b>) AV Block?</b></span></span></li></ul><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh9yNAquG60z9J3RGQxq1s1YK4gEJvHOFUUAD0ll4wAn-l5YuXOEaYccC2BcABZKEI2VXivy6kZjq4vkhZlhsNza8DnuC6xtHclm_7tT4gT3pvPGR_CBlcZUGmNnd4ZdbSGjjrNVw2JePmbu4DOKu1O1knl1hZePD7iYscnDG1WSZm5rbiZ1vh7ABzWSdA/s2980/07bb-Rhythm-Figure-1-without-ECG-1-USEx.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1010" data-original-width="2980" height="135" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh9yNAquG60z9J3RGQxq1s1YK4gEJvHOFUUAD0ll4wAn-l5YuXOEaYccC2BcABZKEI2VXivy6kZjq4vkhZlhsNza8DnuC6xtHclm_7tT4gT3pvPGR_CBlcZUGmNnd4ZdbSGjjrNVw2JePmbu4DOKu1O1knl1hZePD7iYscnDG1WSZm5rbiZ1vh7ABzWSdA/w400-h135/07bb-Rhythm-Figure-1-without-ECG-1-USEx.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial; text-align: justify;"><b style="text-align: start;"><u>Figure-1:</u></b><span style="text-align: start;"> Is this <i><u>complete</u></i> AV Block</span></span><span style="font-family: arial; text-align: justify;">? </span></span></td></tr></tbody></table></div><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><br /></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkBwStZToiVjQgNtzyxpnJJVVa58VFOi892f3riQmKFJQD_gdnWv4k8dhmWPqCHoOjjkhljDRgQGPs72ohQ0vK_09_Khnhz1ul8Y4DsgMuLNYavfOJ2G3DXpqgiAXCSbVjqeAZ64X1xSsAoc326XRfw1kXBehLqJd7_bPh5XDuD4PL31a6hygbZFkSSu8/s2052/The%20System%20I%20Favor%20for%20Rhythm%20Interp-2-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="776" data-original-width="2052" height="151" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkBwStZToiVjQgNtzyxpnJJVVa58VFOi892f3riQmKFJQD_gdnWv4k8dhmWPqCHoOjjkhljDRgQGPs72ohQ0vK_09_Khnhz1ul8Y4DsgMuLNYavfOJ2G3DXpqgiAXCSbVjqeAZ64X1xSsAoc326XRfw1kXBehLqJd7_bPh5XDuD4PL31a6hygbZFkSSu8/w400-h151/The%20System%20I%20Favor%20for%20Rhythm%20Interp-2-USE.png" width="400" /></a></div><div><br /></div><div><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><br /><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEga0L7nl2q9_WPHky_9grar9pqlgfjqsWG-CGIVxxdIMuUyv3acj_6l9wHuGw0xUDZSyngIq_gRn3WFW4EqSQIt65w4DfTEcJ9dXCw1XUOXiKhj1_PrX6v564Z9H9nXCGqMDSwyTNfBkZtcUEaaWUvZd3w2mOt4QGLGN2MhHVz2vQco3iV0UQT6aoK-40I/s2494/03-%20System-Watch%20Ps,Qs,3Rs%20copy.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1732" data-original-width="2494" height="278" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEga0L7nl2q9_WPHky_9grar9pqlgfjqsWG-CGIVxxdIMuUyv3acj_6l9wHuGw0xUDZSyngIq_gRn3WFW4EqSQIt65w4DfTEcJ9dXCw1XUOXiKhj1_PrX6v564Z9H9nXCGqMDSwyTNfBkZtcUEaaWUvZd3w2mOt4QGLGN2MhHVz2vQco3iV0UQT6aoK-40I/w400-h278/03-%20System-Watch%20Ps,Qs,3Rs%20copy.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> The <b><u>P</u></b>s, <b><u>Q</u></b>s, <b>3<u>R</u> Approach</b> to Rhythm Interpretation.</span></span></td></tr></tbody></table><br style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard;" /><div><br /></div><div><br /></div><div><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjHykEhQ3dNdimg2khr6J04BTmrwYljyV0XSD-p1bbZvYOVJOHppBl4np0NPzzHuaLZI-4W6wqp8W617kXAsrsiKuqE5o79Rnb5A33EckBhcug1rCmS8C1F5-YyKyyP2sh5DSVan_8DDymiVUzgG1AypCoXpX1vtAmdChOjuvRTvkn9mP4EGXcdu1YI_eU/s2494/04-%20System-%20Doesn't%20Matter%20what%20Sequence%20copy.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1732" data-original-width="2494" height="278" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjHykEhQ3dNdimg2khr6J04BTmrwYljyV0XSD-p1bbZvYOVJOHppBl4np0NPzzHuaLZI-4W6wqp8W617kXAsrsiKuqE5o79Rnb5A33EckBhcug1rCmS8C1F5-YyKyyP2sh5DSVan_8DDymiVUzgG1AypCoXpX1vtAmdChOjuvRTvkn9mP4EGXcdu1YI_eU/w400-h278/04-%20System-%20Doesn't%20Matter%20what%20Sequence%20copy.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> It does <u style="font-style: italic;">not</u> matter in what sequence you assess the 5 Parameters <b>(</b><i>and I often <u>change</u> the sequence, depending on the rhythm ... </i><b>)</b>.</span></span></td></tr></tbody></table><br style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard;" /><div>=======================================================</div><div><br /></div><div><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKT9DwuwD3KrIwsnuzkQVAtUqwnP9oe12Ld5XQpOJAbXXPWxTQKEOQNr5E2Y54R6SHCBSKEed8lqdFl-Axy58Ah8eZYQHFUS5V6Exef0JmVbMmMfhifCEdFa2tQA9CXSupCBFatkhBceyD1OMIm_1Bq0vGUxJASfJBxB3Laiq2Mjngap9baADaK1EbnZY/s2856/04c-%20KISS%20Method%20for%20AV%20Blocks-3.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1754" data-original-width="2856" height="246" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjKT9DwuwD3KrIwsnuzkQVAtUqwnP9oe12Ld5XQpOJAbXXPWxTQKEOQNr5E2Y54R6SHCBSKEed8lqdFl-Axy58Ah8eZYQHFUS5V6Exef0JmVbMmMfhifCEdFa2tQA9CXSupCBFatkhBceyD1OMIm_1Bq0vGUxJASfJBxB3Laiq2Mjngap9baADaK1EbnZY/w400-h246/04c-%20KISS%20Method%20for%20AV%20Blocks-3.png" width="400" /></a></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjftR_i7t3_K1LyDy8Tv4fSLuHKP6jIjKWayJsfASwcBN0efNZFrPmTKitNzU8lzcGfYnKnWvqvh7EHRq2CQE0GO2w-K-3NmUhreF5Eopmb3442HMINtuh3oPV5_-I14qkKZ_tZMTMNOGzICAqG6hN3D_WJWmJylfdXs1woyRG8oIpvPyF5RYYZwgfMMKI/s2856/05-The%20AV%20Blocks-1st,2nd,3rd%20degree%20blocks.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1754" data-original-width="2856" height="246" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjftR_i7t3_K1LyDy8Tv4fSLuHKP6jIjKWayJsfASwcBN0efNZFrPmTKitNzU8lzcGfYnKnWvqvh7EHRq2CQE0GO2w-K-3NmUhreF5Eopmb3442HMINtuh3oPV5_-I14qkKZ_tZMTMNOGzICAqG6hN3D_WJWmJylfdXs1woyRG8oIpvPyF5RYYZwgfMMKI/w400-h246/05-The%20AV%20Blocks-1st,2nd,3rd%20degree%20blocks.png" width="400" /></a></div><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiXwuiT8WvDWhg-ke4lY0sJTyMnBZEnBuEZmKxVEVH-y_tsWODToqnKPFC6Lz0st3vK3faBM2Rs1eg-g9Ts6lim8BHtcVyob2Dw-eS7lEvvXv1tCnOesm3AKlsXpgPc0qNHC_aJCldte8nYd5EP9RywyWoC07jTzm7fjteh7gvSNdIVSsEriSgd6KyJ0aY/s2856/05d-%20If%20not%201st%20or%203rd%20-%20it%20is%202nd%20degree.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1754" data-original-width="2856" height="246" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiXwuiT8WvDWhg-ke4lY0sJTyMnBZEnBuEZmKxVEVH-y_tsWODToqnKPFC6Lz0st3vK3faBM2Rs1eg-g9Ts6lim8BHtcVyob2Dw-eS7lEvvXv1tCnOesm3AKlsXpgPc0qNHC_aJCldte8nYd5EP9RywyWoC07jTzm7fjteh7gvSNdIVSsEriSgd6KyJ0aY/w400-h246/05d-%20If%20not%201st%20or%203rd%20-%20it%20is%202nd%20degree.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> If the AV block is <u style="font-style: italic;">neither</u> 1st-degree <u style="font-style: italic;">nor</u> 3rd-degree — <i>then it will be <u>some</u> type of </i><b>2nd-degree AV Block!</b></span></span></td></tr></tbody></table><br /><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixMxOH-_00Yi2i0ybeHxI9Y-QP-nMeZIWzKy4V9PSyCwWzslrDVQBIoUg-I-48fybWgn3f1hhdjt6ZAy9Ta3w4trH10KiEyrs08xgef9cEs3c_O0nDC_nzjhdyqHGdBjAHWXxHc1YKx9QRwHRdjFN7h3z-lR3dp3p2ov50vJnaNyD-XzrokKK3xWwSxkg/s1364/06-1st-Degree.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="258" data-original-width="1364" height="76" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixMxOH-_00Yi2i0ybeHxI9Y-QP-nMeZIWzKy4V9PSyCwWzslrDVQBIoUg-I-48fybWgn3f1hhdjt6ZAy9Ta3w4trH10KiEyrs08xgef9cEs3c_O0nDC_nzjhdyqHGdBjAHWXxHc1YKx9QRwHRdjFN7h3z-lR3dp3p2ov50vJnaNyD-XzrokKK3xWwSxkg/w400-h76/06-1st-Degree.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> 1st-degree AV Block — is simply a sinus rhythm with a long PR interval <b>(</b>ie, <i><u>more</u> than 1 large box in duration = >0.20 second</i><b>)</b>. <i>It is EASY to diagnose.</i></span></span></td></tr></tbody></table><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpxFuXSjFbRiGk10OsF775jVoJZTGAY5w94T2y5KowwHd74ujypsL9JrCLwsYLkkf_3SIi8zyZbBeS-hOhqDmbeQgAHU-akxvarUmMRcu4Py34_FFVrdt5dwdHFwB-uQy2sTpU0In_Rkq1tJ6sfcXXSSFKcWqgV_VUorZ2ucg_pQeGLvCIJ_wA3hjZthA/s1338/08d-3rd-Degree.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="272" data-original-width="1338" height="81" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpxFuXSjFbRiGk10OsF775jVoJZTGAY5w94T2y5KowwHd74ujypsL9JrCLwsYLkkf_3SIi8zyZbBeS-hOhqDmbeQgAHU-akxvarUmMRcu4Py34_FFVrdt5dwdHFwB-uQy2sTpU0In_Rkq1tJ6sfcXXSSFKcWqgV_VUorZ2ucg_pQeGLvCIJ_wA3hjZthA/w400-h81/08d-3rd-Degree.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> 3rd-degree AV block with ventricular escape. <i>3rd-degree AV Block is usually <u>also</u> EASY to diagnose — because most of the time the ventricular "escape" rhythm will be regular (or almost regular</i>) — in contrast to <i>conducted</i> beats that will often occur <i>earlier-than-expected </i>...</span></span></td></tr></tbody></table><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div></span></div><div style="caret-color: rgb(13, 13, 13);"><br /></div><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqEykM3HcYhLx-zqw5Cxs_n-8f46cnofGQObiVesNRcbIh9P-crGjofLIcmNOwnV3F2eKpGuW6s0w_BDg6rMajS6x9FTeTJMD-tuDiKM2UdSZUgxba3XPtc2x5se__TueyiH7xq-m3omiz4tYzd-AuK1lt2OAoumUd9_k3ShmOp5ogjGLmjwOMOHF7BUE/s3814/10d-3%20Types%20of%202nd-Degree%20AV%20Block-Wencke-USEx.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="2128" data-original-width="3814" height="224" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhqEykM3HcYhLx-zqw5Cxs_n-8f46cnofGQObiVesNRcbIh9P-crGjofLIcmNOwnV3F2eKpGuW6s0w_BDg6rMajS6x9FTeTJMD-tuDiKM2UdSZUgxba3XPtc2x5se__TueyiH7xq-m3omiz4tYzd-AuK1lt2OAoumUd9_k3ShmOp5ogjGLmjwOMOHF7BUE/w400-h224/10d-3%20Types%20of%202nd-Degree%20AV%20Block-Wencke-USEx.png" width="400" /></a></div><br /><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlqmKlgIeeFa3aFPYq95zxgUl-uH0qsQgEYcBS4o2-JoZ5QNhX0qha3hyYcgpIfUCZ4_8V2ZQaYuPhe8q9aozryv3-aLbYBQCGksd3VXobTtIIFVYc9N7fanH_xuFr_SJFnLugUbG613zzdk-zzQjtlha53o92DhVG_wkAB_o-BNO_fXDEXnbE-3HOA4I/s1358/08b-2nd-Degree%20AV%20Blocks.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="590" data-original-width="1358" height="174" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlqmKlgIeeFa3aFPYq95zxgUl-uH0qsQgEYcBS4o2-JoZ5QNhX0qha3hyYcgpIfUCZ4_8V2ZQaYuPhe8q9aozryv3-aLbYBQCGksd3VXobTtIIFVYc9N7fanH_xuFr_SJFnLugUbG613zzdk-zzQjtlha53o92DhVG_wkAB_o-BNO_fXDEXnbE-3HOA4I/w400-h174/08b-2nd-Degree%20AV%20Blocks.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span><b style="color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; font-family: arial; text-align: justify;"> The <b>3 types</b> of <b>2nd-degree AV block</b>. </span></span><span class="dig-Theme dig-Theme--bright dig-Mode--bright In-Theme-Provider" style="caret-color: rgb(0, 0, 0); display: contents; text-align: start;"><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.0552978515625" lengthadjust="spacingAndGlyphs" textlength="39.9740295410156" x="349.435607910156" y="-555.420043945312"><u>Panel A:</u> </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="63.8891296386719" x="404.345550537109" y="-555.420043945312"><b>Mobitz I</b> 2nd </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="104.23509979248" x="79.8335647583008" y="-543.659973144531">degree AV block with </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="37.0298767089844" x="188.436325073242" y="-543.659973144531">gradual </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="239.001770019531" x="229.253021240234" y="-543.659973144531">prolongation of the PR interval until a P wave is </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="39.2340469360352" x="79.8335647583008" y="-531.900024414062">dropped</text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="1.12176513671875" lengthadjust="spacingAndGlyphs" textlength="2.22383117675781" x="210.026473999023" y="-531.900024414062">. </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.0552978515625" lengthadjust="spacingAndGlyphs" textlength="38.8128967285156" x="216.389984130859" y="-531.900024414062"><u>Panel B:</u> </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="172.630035400391" x="268.502105712891" y="-531.900024414062"><b>Mobitz II</b> with QRS widening and a </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="24.5823059082031" x="443.92138671875" y="-531.900024414062"><i><u>fixed</u></i> </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="247.04899597168" x="79.8827667236328" y="-520.380004882812">PR interval until sudden loss of conduction with </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="50.3188171386719" x="332.538452148438" y="-520.380004882812">successive </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="80.3101501464844" x="387.923370361328" y="-520.380004882812">nonconducted P </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="6.9962158203125" lengthadjust="spacingAndGlyphs" textlength="38.710563659668" x="79.4399642944336" y="-508.619995117188">waves</text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="6.9962158203125" lengthadjust="spacingAndGlyphs" textlength="5.90794372558594" x="204.833251953125" y="-508.619995117188">. </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.0552978515625" lengthadjust="spacingAndGlyphs" textlength="42.1880035400391" x="224.825698852539" y="-508.619995117188"><u>Panel C:</u> </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04541015625" lengthadjust="spacingAndGlyphs" textlength="181.746734619141" x="286.457092285156" y="-508.619995117188"><b>2nd-degree AV block with 2:1 AV </b></text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04544067382812" lengthadjust="spacingAndGlyphs" textlength="388.50757598877" x="79.8434066772461" y="-496.859985351562"><b>conduction</b>. It is impossible to be certain if 2:1 AV block represents Mobitz I or </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04544067382812" lengthadjust="spacingAndGlyphs" textlength="106.487510681152" x="79.9024429321289" y="-485.100006103516">Mobitz II — because we </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="4.83145141601562" lengthadjust="spacingAndGlyphs" textlength="26.2708282470703" x="191.346206665039" y="-485.100006103516"><i><u>never</u></i> </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04544067382812" lengthadjust="spacingAndGlyphs" textlength="168.214797973633" x="221.10612487793" y="-485.100006103516">see 2 conducted P waves in a row — </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04544067382812" lengthadjust="spacingAndGlyphs" textlength="17.8399353027344" x="402.502471923828" y="-485.100006103516">and, </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04544067382812" lengthadjust="spacingAndGlyphs" textlength="43.2753295898438" x="424.956298828125" y="-485.100006103516">therefore </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="6.25823974609375" lengthadjust="spacingAndGlyphs" textlength="31.7635192871094" x="80.2763671875" y="-473.339996337891">can <i><u>not</u></i> </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04544067382812" lengthadjust="spacingAndGlyphs" textlength="127.598190307617" x="121.611068725586" y="-473.339996337891">tell if the PR interval </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04544067382812" lengthadjust="spacingAndGlyphs" textlength="29.0280151367188" x="259.351287841797" y="-473.339996337891">would </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04544067382812" lengthadjust="spacingAndGlyphs" textlength="115.31689453125" x="299.227142333984" y="-473.339996337891">progressively lengthen </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="6.91751098632812" lengthadjust="spacingAndGlyphs" textlength="42.8689270019531" x="425.375671386719" y="-473.339996337891">prior to </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04544067382812" lengthadjust="spacingAndGlyphs" textlength="72.6861267089844" x="79.8040466308594" y="-461.579986572266">nonconduction </text><text class="_textbox_1titd_17" data-test="textbox" direction="ltr" height="7.04544067382812" lengthadjust="spacingAndGlyphs" textlength="138.427139282227" x="156.439987182617" y="-461.579986572266"><u>IF</u> given a chance to do so ... <b>(</b><i>That said — 90-95% of 2nd-degree AV Blocks are Mobitz I — and Mobitz I especially likely if the QRS is wide, with 1st-degree, in a patient with acute inferior MI</i><b>)</b>.</text></span></span></td></tr></tbody></table><p></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><br /></p><p></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjveeAKROE_Sbtco2OLS5DMq8kDxzQ5ADOECqn-ncdnOJDEGGxZ0_-rr8hzgtL0oO5VP1_dMtLd8W2ryZ1o-KmYcSeV7LrYQREt8wKX3qzyU1IVsEHbfH9L60hQEoTzqt0o5PEEfaTOY1OxiYPMDVuyThQjuHRoot9Wevn6SuWMET2rbHKBIxMgobYh5HI/s1360/08c-2-1%202nd%20Degree.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="276" data-original-width="1360" height="81" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjveeAKROE_Sbtco2OLS5DMq8kDxzQ5ADOECqn-ncdnOJDEGGxZ0_-rr8hzgtL0oO5VP1_dMtLd8W2ryZ1o-KmYcSeV7LrYQREt8wKX3qzyU1IVsEHbfH9L60hQEoTzqt0o5PEEfaTOY1OxiYPMDVuyThQjuHRoot9Wevn6SuWMET2rbHKBIxMgobYh5HI/w400-h81/08c-2-1%202nd%20Degree.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; font-family: arial; text-align: justify;"> 2nd-degree AV block with <b>2:1 AV conduction</b>.</span></span></td></tr></tbody></table><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><br /></span></div><br style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard;" /><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhut78R9SGDMu-Cn8vKOVj6zderCj7mzz0djZp2mYWymsM-ZlZtpacQe1BU8HPf7bXmnimmTZ3qJ2eSp3SmLeeHa8IN1k8Abnv1He8kHSI7vGQ7aEBexCVG38mL1rhH_rDOKx0UTeqN3qKldPmALQcmtdqF8e_oJfo1_gJWH7F0shyTNL6vFFRpXxDkcVc/s1356/06e-High-Grade%20copy.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="232" data-original-width="1356" height="69" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhut78R9SGDMu-Cn8vKOVj6zderCj7mzz0djZp2mYWymsM-ZlZtpacQe1BU8HPf7bXmnimmTZ3qJ2eSp3SmLeeHa8IN1k8Abnv1He8kHSI7vGQ7aEBexCVG38mL1rhH_rDOKx0UTeqN3qKldPmALQcmtdqF8e_oJfo1_gJWH7F0shyTNL6vFFRpXxDkcVc/w400-h69/06e-High-Grade%20copy.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(13, 13, 13); color: #0d0d0d; font-family: arial; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(13, 13, 13); color: #050505; font-family: arial; text-align: justify;"> This is <b><i><u>high</u>-grade</i> 2nd-degree AV Block</b> — as identified by the finding of at least 2 consecutive <i>on-time</i> P waves that <u style="font-style: italic;">fail</u> to conduct <u style="font-style: italic;">despite</u> adequate opportunity to do so (<i>occurring here between beats #2-3</i>).</span></span></td></tr></tbody></table><p></p><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><span style="text-align: justify;">=======================================================</span></div><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEga1lFc4kEPENqXPaGp68gJDuBffU-IJUcQDXpShjHfn-wxdRSG-pYQq61VtramjcOl0EBQAjIivGH8lomHyjpJmJHfIOJTS4t99INFmMOPmSonZ7cdSl65WanWHxQ_-KZZGjO6DTQKCt0L6hHLnKIAenBxrEtP0W-LJDFoFF5cX1YnfdFAgxT9tEeYT-g/s2150/11a-Types%20of%20AV%20Diss-SMALL-USEx.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="864" data-original-width="2150" height="161" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEga1lFc4kEPENqXPaGp68gJDuBffU-IJUcQDXpShjHfn-wxdRSG-pYQq61VtramjcOl0EBQAjIivGH8lomHyjpJmJHfIOJTS4t99INFmMOPmSonZ7cdSl65WanWHxQ_-KZZGjO6DTQKCt0L6hHLnKIAenBxrEtP0W-LJDFoFF5cX1YnfdFAgxT9tEeYT-g/w400-h161/11a-Types%20of%20AV%20Diss-SMALL-USEx.png" width="400" /></a></div><br /><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0kV_pEetrAz6KHDWjC1zw-wF-w5uO2wcFEI3RdBnATNxD16Xl2dDK7Y4QzpgmbbR72dTCEjKqHOAHiuzm3dq2zr_PzBE6Vr3M03kqnK-rnoajkHeooiTfPMP5yKOguPY5y-6TWCz7aaqaXvaOOkYpoyZl7BkDsZVcVmhVqsK4jmp8sq2aJ-3EQihrZ7s/s3034/11c-AV%20Diss%20by%20Default-USEx.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="542" data-original-width="3034" height="71" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0kV_pEetrAz6KHDWjC1zw-wF-w5uO2wcFEI3RdBnATNxD16Xl2dDK7Y4QzpgmbbR72dTCEjKqHOAHiuzm3dq2zr_PzBE6Vr3M03kqnK-rnoajkHeooiTfPMP5yKOguPY5y-6TWCz7aaqaXvaOOkYpoyZl7BkDsZVcVmhVqsK4jmp8sq2aJ-3EQihrZ7s/w400-h71/11c-AV%20Diss%20by%20Default-USEx.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; font-family: arial; text-align: justify;"> AV dissociation by <i><b>"</b><u style="font-weight: bold;">default</u><b>"</b> — </i>because the SA node slows, with result takeover by the AV node. <i>There is <u>not</u> necessarily any degree of AV block with this!</i> </span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13);"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9SRS3nQXdNDwHU2ruGnQiysICj86G-enS43lt8n2oAdUKLEie_JOlDrd6spG7VILKSw1GHqFTutLQaysO-Ff0fZiUKgdSScndwJA4863IxHGqPFalLIQQcZiryUk7VpjU4fAc-KsLfmNotbr0AS9y6oN_bgWlt1v-uG6J5Li6mN7j1WxbVirW_qEOmL0/s2888/11aacc-AV%20Diss%20by%20Usurpation.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="458" data-original-width="2888" height="64" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9SRS3nQXdNDwHU2ruGnQiysICj86G-enS43lt8n2oAdUKLEie_JOlDrd6spG7VILKSw1GHqFTutLQaysO-Ff0fZiUKgdSScndwJA4863IxHGqPFalLIQQcZiryUk7VpjU4fAc-KsLfmNotbr0AS9y6oN_bgWlt1v-uG6J5Li6mN7j1WxbVirW_qEOmL0/w400-h64/11aacc-AV%20Diss%20by%20Usurpation.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; font-family: arial; text-align: justify;"> AV dissociation by <i style="font-weight: bold;">"<u>usurpation</u>"</i> — because either the AV node or the ventricles <i>speed up</i>, and take over the rhythm from the SA node. <i>There is <u>not</u> necessarily any degree of AV block with this! (and the KEY is to figure out WHY the AV node or ventricles have "taken over" the rhythm</i>). </span></span></td></tr></tbody></table><br /></div><div style="caret-color: rgb(13, 13, 13);"><br /></div><div style="caret-color: rgb(13, 13, 13);"><span style="font-family: arial; font-size: medium;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhM8maj6GLjJ6mZcXHZ4YLjcv_G9PUpM2S_vpiyF1IaYl_nxKwc3a3nVPnrKA-oJoWe0R6xfV7Omy50D7bty44jcbyVDrdvt31mhrS9et8qV97XYKamSn7xh4-RHiS8dhAmL1LdEUH3GVgNjueQxO7pu1Q1AH_rRWxk8qYunjcZ2Fa6arrIaj21iER7CQ0/s2188/Anatomic%20Level%20of%20Complete%20AV%20Block-2.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="778" data-original-width="2188" height="143" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhM8maj6GLjJ6mZcXHZ4YLjcv_G9PUpM2S_vpiyF1IaYl_nxKwc3a3nVPnrKA-oJoWe0R6xfV7Omy50D7bty44jcbyVDrdvt31mhrS9et8qV97XYKamSn7xh4-RHiS8dhAmL1LdEUH3GVgNjueQxO7pu1Q1AH_rRWxk8qYunjcZ2Fa6arrIaj21iER7CQ0/w400-h143/Anatomic%20Level%20of%20Complete%20AV%20Block-2.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> Anatomic levels of 3rd-degree AV Block. <u>Panel A:</u> <b>Complete AV Block</b> at the <b><u style="font-style: italic;">ventricular</u> level</b>. There is a regular atrial rhythm — and the QRS is wide with an idioventricular <i>escape</i> rhythm at a rate <i>between </i>20-40/minute. <u>Panel B:</u> <b>Complete AV Block</b> at a <b><u style="font-style: italic;">higher</u> level (</b><i>probably in the AV node</i><b>)</b> — as suggested by the presence of a <i>narrow </i>QRS escape rhythm at a rate <i>between </i>40-60/minute.<br /><br /><u style="font-weight: bold;">NOTE:</u> The <i>KEY</i> criterion for diagnosing complete AV block — is that <u style="font-style: italic;">none</u> of the on-time sinus P waves are being conducted to the ventricles <u style="font-style: italic;">despite</u> having more than adequate opportunity to do so! <b>(</b><i>which usually requires a long enough rhythm strip at a slow enough rate = <50-55/minute — in order to guarantee that on-time P waves are occurring at <u>all</u> points in the cycle — but still fail to conduct</i><b>)</b>.</span></span></td></tr></tbody></table></span></div><div style="caret-color: rgb(13, 13, 13);"><br /></div><br /><div><br /></div><div>=======================================================</div><div><br /></div><div><br /></div><div class="separator" style="clear: both; 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font-family: -webkit-standard; margin: 0in;"><br /></p><div>=======================================================</div><br style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard;" /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrAyeHXVNQyGA8WujaZqFxYaI3Q6ujWx75p30ds7vlIml-Q2OLGh4NESplDTP2Q4tRkCig1Gf6sRCtn0gbLWtEX-HArJHeZVQiDdMA4LcY9aGlKgF7rG1QFC7ifVqvlKz0OKQlyRHOQXoQLaLIrf72sjcQ9xkqZgh63hORz_zlTlBWkhpp4vgJt9OzuSY/s2120/09-%20The%20Laddergram-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="468" data-original-width="2120" height="71" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrAyeHXVNQyGA8WujaZqFxYaI3Q6ujWx75p30ds7vlIml-Q2OLGh4NESplDTP2Q4tRkCig1Gf6sRCtn0gbLWtEX-HArJHeZVQiDdMA4LcY9aGlKgF7rG1QFC7ifVqvlKz0OKQlyRHOQXoQLaLIrf72sjcQ9xkqZgh63hORz_zlTlBWkhpp4vgJt9OzuSY/s320/09-%20The%20Laddergram-USE.png" width="320" /></a></div><span style="font-family: arial; font-size: medium;"><div><br /></div><br /></span><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEivVA3r6vpWMi62XlmfMGePA3jYwJhTLSpJ3fbSf5co2JT17QO9GQLqsTLX1yIQWQQlp8Jx_1zlM-2jCiRbpzNONgIgqhjnr6LdGlN1RbXMLZWr4iDkCNizdtbO7z9Nq98wjXganGE7qefsDv8m85wtEfB3LJ3k6t8LA3DOxSUJa6DYh-LAr454ZJwdkb8/s1920/10-Laddergram-thru%20Atrial%20Tier.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1080" data-original-width="1920" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEivVA3r6vpWMi62XlmfMGePA3jYwJhTLSpJ3fbSf5co2JT17QO9GQLqsTLX1yIQWQQlp8Jx_1zlM-2jCiRbpzNONgIgqhjnr6LdGlN1RbXMLZWr4iDkCNizdtbO7z9Nq98wjXganGE7qefsDv8m85wtEfB3LJ3k6t8LA3DOxSUJa6DYh-LAr454ZJwdkb8/w400-h225/10-Laddergram-thru%20Atrial%20Tier.jpg" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; font-family: arial; text-align: justify;"> Laddergram of today's rhythm through the Atrial Tier.</span></span></td></tr></tbody></table><br /><p></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixGFtmJWL8F48ArBFyVYpJaPz_sOjhZSZevCU0IAEQTWQ-NcJ4Ielt50eKJibl79wGtWJ1iPCOifJWZE0kalvsPnIfTxKaOc5AstJf8ZsomHzjSNFraxwtXcyE2ZtRp5ykTZzrelg2tKXiu_KtZHFh8DXvuTSbQFa0o1o5u71miUjvd1nP1qw1uxWmAXo/s3272/z-LADDERGRAM-long%20Rhythm%20(191).png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1626" data-original-width="3272" height="199" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixGFtmJWL8F48ArBFyVYpJaPz_sOjhZSZevCU0IAEQTWQ-NcJ4Ielt50eKJibl79wGtWJ1iPCOifJWZE0kalvsPnIfTxKaOc5AstJf8ZsomHzjSNFraxwtXcyE2ZtRp5ykTZzrelg2tKXiu_KtZHFh8DXvuTSbQFa0o1o5u71miUjvd1nP1qw1uxWmAXo/w400-h199/z-LADDERGRAM-long%20Rhythm%20(191).png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; font-family: arial; text-align: justify;"> Completed <b><i><u>laddergram</u></i></b> of today's rhythm. There is AV dissociation for the first 5 beats with ventricular escape (<i>AV dissociation as a result of AV block</i>). Because of underlying sinus arrhythmia — the P wave in front of beat #6 occurs at an opportune time, and is able to conduct to the ventricles. The remaining beats (<i> = beats #6-thru-9</i>) conduct with 2:1 AV block. Because Mobitz I is some much more common than Mobitz II — and especially because the QRS complex for these conducted beats is narrow — there is almost certainly <b>2nd-degree AV Block</b> of the <b>Mobitz I Type ( </b>= <i>AV Wenckebach</i><b>)</b> — here with AV dissociation initially, and 2:1 AV block for the last few beats in the tracing.</span></span></td></tr></tbody></table><div class="separator" style="clear: both; text-align: center;"><br /></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><br /></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in; text-align: center;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1YwNX4Pgn2HbCNcLCEN20_vF-M0zgHzIa9FFUfC5qlvgirrxgeaNQRYghKydgXM0uJLyUBJYWO8_kZvEmNq7M_H_m3OYDuJWlFQUHxiAtgJ69Dng8fcWG6wIV9CKJvZVRn52XfEkNwBU/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1YwNX4Pgn2HbCNcLCEN20_vF-M0zgHzIa9FFUfC5qlvgirrxgeaNQRYghKydgXM0uJLyUBJYWO8_kZvEmNq7M_H_m3OYDuJWlFQUHxiAtgJ69Dng8fcWG6wIV9CKJvZVRn52XfEkNwBU/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div class="separator" style="clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><br /></div><div class="separator" style="clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><br /></div><div class="separator" style="clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><br /></div><div class="separator" style="clear: both; color: #050505; font-family: -webkit-standard;"><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;">==================================</span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><div style="text-align: justify;"><b style="font-family: arial;"><u><i><span style="color: red;">A</span>dditional</i> <span style="color: red;">M</span>aterial on <i><span style="color: red;">T</span>oday's</i> <span style="color: red;">C</span>ASE:</u></b></div><div style="text-align: justify;"><b style="font-family: arial;"><u><br /></u></b></div></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(0, 0, 0); margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td><div class="separator" style="clear: both;"><a href="https://dl.dropboxusercontent.com/s/p5o4fsrvt6mzqv3/z-ECG%20Audio%20Pearl-4%20%282-12.1-2021%29-USE-Faster.m4a?dl=0" target="_blank"><span style="font-family: arial; font-size: medium;">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1470" data-original-width="2048" height="288" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUAcJgawC2j9KDwKlACfTSKiiFHIo_a9sS0f1ZnbphiPfeBWj2mSS913KvLr_WX6iCOOpF-G8Bprw20u8pN73MMgyBaMr4Q21EXsDMgYLbRZSWW-bKbUSMQjiEFEj72JNPtxlA1iLfHe8/w400-h288/MP-4+%2528186%2529-Suspect+Mobitz+I-USE.png" width="400" /></span> —</span></a></div><span style="font-family: arial; font-size: medium;"><br /></span></td></tr><tr><td class="tr-caption"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span><span>4</span></u></b><b style="text-align: justify;"> (</b><i><span style="text-align: justify;">4:3</span><span style="text-align: justify;">0</span></i><i style="text-align: justify;"> minutes <b><u>Audio</u></b></i><b style="text-align: justify;">)<span style="color: red;">:</span></b><span style="text-align: justify;"> — takes a brief look at the <b>AV Blocks</b> — and focuses on <i>WHEN</i> to <i>suspect</i> <b>Mobitz I</b>.</span></span></td></tr></tbody></table><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><br /></p><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwH4zab67Smbft7R9OPI1Qt_EIabvd1wkRjbtgdprf9x2DTzFyxpfip8X5v1FQ1JRipbXXDMjNsoFUG5Ly7O5PM-dQypN1q5O7es89cSBR7bLiSIyXgqgKiPOE4sddPqpzEmyZ97L5eak/s3070/MP-8+%2528191-Video%2529+AV+Diss+vs+Complete+AV+Block-USE+copy.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="314" data-original-width="3070" height="41" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgwH4zab67Smbft7R9OPI1Qt_EIabvd1wkRjbtgdprf9x2DTzFyxpfip8X5v1FQ1JRipbXXDMjNsoFUG5Ly7O5PM-dQypN1q5O7es89cSBR7bLiSIyXgqgKiPOE4sddPqpzEmyZ97L5eak/w400-h41/MP-8+%2528191-Video%2529+AV+Diss+vs+Complete+AV+Block-USE+copy.png" width="400" /></a></div><b style="text-align: justify;"><br /></b></span></div><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dzQiWbbqUXndiiN3MIEqpHbeXOGuxZFeJH9CK1hbyHR0tkPR8S1cSx9calwdnlW_C6GcCNwr7jDZBIsjI28pQ' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div></span></div><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;">ECG Media Pearl <span style="color: red;">#</span>8 (</b><i style="text-align: justify;">8:20 minutes <b><u>Video</u></b></i><b style="text-align: justify;">)</b><span style="text-align: justify;"> — <b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-191-ecg-mp-8-is-av-block.html" target="_blank">ECG Blog #191</a></b> — Distinguishing between <b><span style="color: red;">A</span>V <span style="color: red;">D</span>issociation</b> <u>vs</u> <b>Complete AV Block (</b><i>2/6/2021</i><b>)</b>.</span></span></div><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><br /></b></span></div><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><br /></b></span></div><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><br /></b></span></div><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWChGeXVP0DDrXM8tMWCDsC8lzeWBDX5T2oTgH0eNbHd-3kACbTcZt7FA8E8Q4cXmYXNr4kd0o3agQkVm2qppt2tqHgxvK3t-e1wWlOM66onmMH8RPofPZHAKJkp48slLOL4tTcTYDvTk/s2736/MP-9+%2528192-Video%2529+Causes+of+AV+Dissociatio-USE+copy.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="292" data-original-width="2736" height="43" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjWChGeXVP0DDrXM8tMWCDsC8lzeWBDX5T2oTgH0eNbHd-3kACbTcZt7FA8E8Q4cXmYXNr4kd0o3agQkVm2qppt2tqHgxvK3t-e1wWlOM66onmMH8RPofPZHAKJkp48slLOL4tTcTYDvTk/w400-h43/MP-9+%2528192-Video%2529+Causes+of+AV+Dissociatio-USE+copy.png" width="400" /></a></div><b style="text-align: justify;"><br /></b></span></div><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dxyQxDutW6rVfcAXkolKPqkAVCMpA6D5o8DlFVYbDIFmRv7xOaS0di8Tk9QigeKm_26YCAcnPCMfSdfnyZg1g' class='b-hbp-video b-uploaded' frameborder='0'></iframe></div></span></div><div style="caret-color: rgb(0, 0, 0); color: black; text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;">ECG Media Pearl <span style="color: red;">#</span>9 (</b><i style="text-align: justify;">5:40 minutes <b><u>Video</u></b></i><b style="text-align: justify;">)</b><span style="text-align: justify;"> — <b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" target="_blank">ECG Blog #192</a></b> — Reviews the <b>3 Causes</b> of <b>AV Dissociation (</b><i>2/9/2021</i><b>)</b>.</span></span></div><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><br /></p><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://www.dropbox.com/s/v01yvlqafd5c6z2/AV%20Blocks-Pg%2060-66%20ECG-PB%20%281-16.22-2021%29-USE.pdf?dl=0" target="_blank">Section 2F</a> (</b><i>6 pages = the <b>"<u>short</u>" Answer</b></i><b>)</b> from my ECG-2014 Pocket Brain book provides quick written review of the <b>AV Blocks (</b><i>This is a free download</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><span><b><a href="https://www.dropbox.com/s/k1jk1y4o4uu48ab/20.0-%20ACLS-2013-e-PUB-AV%20Block-Dissociaton-%2810-15.11-2014%29-LOCK.pdf?dl=0" target="_blank">Section 20</a></b> </span><b>(</b><i>54</i><i> pages = the <b>"<u>long</u>" Answer</b></i><b>)</b> from my ACLS-2013-Arrhythmias <i>Expanded</i> Version provides <i>detailed</i> discussion of <i>WHAT</i> the <b>AV Blocks</b> ar</span><span style="font-family: arial;">e — and what they are <u>not</u>! </span>(<i>This is a free download</i>). </li></ul></div></span></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;">=======================<o:p></o:p></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><i><u>Related</u></i></b><b><u> ECG Blog Posts to <i>Today’s</i> Case:</u> </b></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"></p><ul style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — Review of the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach</b> for systematic rhythm interpretation.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> <b><i>draw</i></b> </span><span style="font-family: arial; font-size: medium;"><b>L</b></span><b style="font-family: arial;">addergrams (</b><i style="font-family: arial;">with LINKS to more than 50 laddergram cases — many with step-by-step sequential illustration</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2019/05/ecg-blog-164-pacs-blocked-pacs.html" target="_blank">ECG Blog #164</a></b> — Which reviews <i>step-by-step</i> the diagnosis of a <b>Mobitz I 2nd-degree AV block (</b><i>with sequential laddergram illustration</i><b>)</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2019/09/ecg-blog-168-stemi-complex-av-block.html" target="_blank">ECG Blog #168</a></b> — A complex <b><i>dual-level </i>AV Wenckebach (</b><i>Laddergram</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2018/07/ecg-blog-154-stemi-inferior-mobitz.html" target="_blank">ECG Blog #154</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2012/11/ecg-interpretation-review-55-mobitz-i.html" target="_blank">ECG Blog #55</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2021/05/the-12-lead-ecg-and-long-lead-ii-rhythm.html" target="_blank">ECG Blog #224</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2021/06/ecg-blog-232-47-what-is-bigeminy.html" target="_blank">ECG Blog #232 </a></b>— <b><i>Acute</i> MI</b> with <b>AV Wenckebach</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2013/03/ecg-interpretation-review-63-av-block.html" target="_blank">ECG Blog #63</a></b> — <b>Mobitz I</b> with <b>Junctional <i>Escape</i> Beats</b>.</span></li></ul><p style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><div class="separator" style="caret-color: rgb(0, 0, 0); clear: both; color: black; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgToTJ6lth3lK5od4oIJM19G0r2sow_0nRRUfJIWtbXsVgI9VRfD_2l6pDgP7KomUFRc9OxYFCdMVG557HCCvVB_1UBm2WrVZA2bq_4rZu3uIWAFGZUsD8V-_ZempjCZoodyin28DOEj7Y/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgToTJ6lth3lK5od4oIJM19G0r2sow_0nRRUfJIWtbXsVgI9VRfD_2l6pDgP7KomUFRc9OxYFCdMVG557HCCvVB_1UBm2WrVZA2bq_4rZu3uIWAFGZUsD8V-_ZempjCZoodyin28DOEj7Y/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div><br /></div></div></span></div><div style="caret-color: rgb(13, 13, 13);"><br /></div></div></span></span></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-68774955294631478612023-11-18T09:36:00.002-05:002023-11-18T16:10:01.448-05:00ECG Video Blog #404 (344) — Mobitz I, Mobitz II ... or neither?<div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div><span style="color: #050505;"><span style="font-family: arial; font-size: medium;">======================================</span></span></div><div><span><span style="font-family: arial; font-size: medium;"><span style="color: #050505;"> —</span><i style="color: #050505;"> </i><b style="color: #050505;"><a href="https://youtu.be/sP3tab_zsTI" target="_blank">CLICK HERE</a></b><i style="color: #050505;"> — for a </i><u style="font-weight: bold;"><span style="color: red;">V</span><span style="color: #050505;">ideo</span></u><span style="color: #050505;"> presentation of this case! (<i>15 minutes</i>)</span></span></span></div><p class="MsoNormal" style="margin: 0in;"></p><ul><li><span style="color: #050505;">Below are slides used in my video presentation.</span></li><li><span style="color: #050505;">For full discussion of this case — <i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-344-mobitz-i-mobitz-ii-or.html" target="_blank">ECG Blog #344</a> </b>—</span></li></ul><p></p><div><span style="color: #050505;"><span style="font-family: arial; font-size: medium;">======================================</span></span></div><div><br /></div></div></span><div><span style="font-size: medium;"><span style="background-color: white; white-space: pre-wrap;"><div style="text-align: justify;"><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><span style="font-family: arial; font-size: medium;"><i>How would YOU interpret</i> the lead II rhythm strip shown in <b><u>Figure-1</u>?</b></span></div><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: left;"><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Is the rhythm <b>Mobitz I</b> <i><u>or</u></i> <b>Mobitz II 2nd-degree AV Block?</b> </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Or —<i> Is it “<u>something</u> <u>else</u>”?</i></span></li></ul></div><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td style="text-align: justify;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEim0kBvBWQtQd82nG98iedzezYePGq7BJh47cdB-rSXLnRf07ssG0cGuTwe3iwXwqrTqI6uJwqfrCqyLObLgXT68dTJChom1qOYQW_X5-qquk-ITgpwcFfE35e49l1si49SLMT53xd628-ra_zFKZPjWyd-xxUWzi-2ego3Bt2EbQrx8ohWkNOUtSYk/s3320/Figure-1%20%20Lead%20II%20(11-1.21-2022)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="618" data-original-width="3320" height="75" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEim0kBvBWQtQd82nG98iedzezYePGq7BJh47cdB-rSXLnRf07ssG0cGuTwe3iwXwqrTqI6uJwqfrCqyLObLgXT68dTJChom1qOYQW_X5-qquk-ITgpwcFfE35e49l1si49SLMT53xd628-ra_zFKZPjWyd-xxUWzi-2ego3Bt2EbQrx8ohWkNOUtSYk/w400-h75/Figure-1%20%20Lead%20II%20(11-1.21-2022)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b style="text-align: start;"><u>Figure-1:</u></b><span style="text-align: start;"> </span></span>How would <i>YOU</i> interpret this lead II rhythm strip?</span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><div><br /></div></span></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><br /></p><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkBwStZToiVjQgNtzyxpnJJVVa58VFOi892f3riQmKFJQD_gdnWv4k8dhmWPqCHoOjjkhljDRgQGPs72ohQ0vK_09_Khnhz1ul8Y4DsgMuLNYavfOJ2G3DXpqgiAXCSbVjqeAZ64X1xSsAoc326XRfw1kXBehLqJd7_bPh5XDuD4PL31a6hygbZFkSSu8/s2052/The%20System%20I%20Favor%20for%20Rhythm%20Interp-2-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="776" data-original-width="2052" height="151" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkBwStZToiVjQgNtzyxpnJJVVa58VFOi892f3riQmKFJQD_gdnWv4k8dhmWPqCHoOjjkhljDRgQGPs72ohQ0vK_09_Khnhz1ul8Y4DsgMuLNYavfOJ2G3DXpqgiAXCSbVjqeAZ64X1xSsAoc326XRfw1kXBehLqJd7_bPh5XDuD4PL31a6hygbZFkSSu8/w400-h151/The%20System%20I%20Favor%20for%20Rhythm%20Interp-2-USE.png" width="400" /></a></div><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(13, 13, 13); font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEga0L7nl2q9_WPHky_9grar9pqlgfjqsWG-CGIVxxdIMuUyv3acj_6l9wHuGw0xUDZSyngIq_gRn3WFW4EqSQIt65w4DfTEcJ9dXCw1XUOXiKhj1_PrX6v564Z9H9nXCGqMDSwyTNfBkZtcUEaaWUvZd3w2mOt4QGLGN2MhHVz2vQco3iV0UQT6aoK-40I/s2494/03-%20System-Watch%20Ps,Qs,3Rs%20copy.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1732" data-original-width="2494" height="278" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEga0L7nl2q9_WPHky_9grar9pqlgfjqsWG-CGIVxxdIMuUyv3acj_6l9wHuGw0xUDZSyngIq_gRn3WFW4EqSQIt65w4DfTEcJ9dXCw1XUOXiKhj1_PrX6v564Z9H9nXCGqMDSwyTNfBkZtcUEaaWUvZd3w2mOt4QGLGN2MhHVz2vQco3iV0UQT6aoK-40I/w400-h278/03-%20System-Watch%20Ps,Qs,3Rs%20copy.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> The <b><u>P</u></b>s, <b><u>Q</u></b>s, <b>3<u>R</u> Approach</b> to Rhythm Interpretation.</span></span></td></tr></tbody></table><br /><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(13, 13, 13); font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjHykEhQ3dNdimg2khr6J04BTmrwYljyV0XSD-p1bbZvYOVJOHppBl4np0NPzzHuaLZI-4W6wqp8W617kXAsrsiKuqE5o79Rnb5A33EckBhcug1rCmS8C1F5-YyKyyP2sh5DSVan_8DDymiVUzgG1AypCoXpX1vtAmdChOjuvRTvkn9mP4EGXcdu1YI_eU/s2494/04-%20System-%20Doesn't%20Matter%20what%20Sequence%20copy.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1732" data-original-width="2494" height="278" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjHykEhQ3dNdimg2khr6J04BTmrwYljyV0XSD-p1bbZvYOVJOHppBl4np0NPzzHuaLZI-4W6wqp8W617kXAsrsiKuqE5o79Rnb5A33EckBhcug1rCmS8C1F5-YyKyyP2sh5DSVan_8DDymiVUzgG1AypCoXpX1vtAmdChOjuvRTvkn9mP4EGXcdu1YI_eU/w400-h278/04-%20System-%20Doesn't%20Matter%20what%20Sequence%20copy.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> It does <u style="font-style: italic;">not</u> matter in what sequence you assess the 5 Parameters <b>(</b><i>and I often <u>change</u> the sequence, depending on the rhythm ... </i><b>)</b>.</span></span></td></tr></tbody></table><br /><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial;">=======================================================</div><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjp6E-qHwwogUZ4JitYah2_wlwyZ6TfsYUAQEoHVaEpa6NO0plhOTCt7Htuahy0gJ45pCDKDvGna-2rq9R0yIhHYnFU8sWTe9GRj-V81NJuvPYe4DlrrkBgInk7CzHyprub0JiBdTqeJh8iQVTb7XkUAk4Yi9hXNtVQN_1R9E___SKTA2FUavH6Jf-ALdg/s2322/04a-%20Let's%20Get%20to%20Todays%20Case-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1246" data-original-width="2322" height="215" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjp6E-qHwwogUZ4JitYah2_wlwyZ6TfsYUAQEoHVaEpa6NO0plhOTCt7Htuahy0gJ45pCDKDvGna-2rq9R0yIhHYnFU8sWTe9GRj-V81NJuvPYe4DlrrkBgInk7CzHyprub0JiBdTqeJh8iQVTb7XkUAk4Yi9hXNtVQN_1R9E___SKTA2FUavH6Jf-ALdg/w400-h215/04a-%20Let's%20Get%20to%20Todays%20Case-USE.png" width="400" /></a></div><br /><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEheXh07oTnbZJFLGcmgAsVS4guHTkVjI_r43U7CAUe46oW4lcBabwdH6JDWfyOzQkcf_UcP7nHSRTgnAKXIPmKDscfFPnIbSg5i98hcXyou-5ZR__adQoTMeg_VfqexJiJzwlbpr7hZwrO7pyiWCPtT_9Kw973dEDK_amvjMHVA5S7H6hlmtjS9l-GeORw/s1076/05-%20Todays%20CASE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="486" data-original-width="1076" height="181" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEheXh07oTnbZJFLGcmgAsVS4guHTkVjI_r43U7CAUe46oW4lcBabwdH6JDWfyOzQkcf_UcP7nHSRTgnAKXIPmKDscfFPnIbSg5i98hcXyou-5ZR__adQoTMeg_VfqexJiJzwlbpr7hZwrO7pyiWCPtT_9Kw973dEDK_amvjMHVA5S7H6hlmtjS9l-GeORw/w400-h181/05-%20Todays%20CASE.png" width="400" /></a></div><br /><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><br /></div><p style="caret-color: rgb(13, 13, 13); font-family: arial;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"></span></span></p><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEggQHx5PCvYKmK_u_pEN0nLGyk_-sOJNah7FN0QB-FiSVEqoYS7UMcBTB9cOy8P2oitVN-prpPz5Had10XMgfWZZBSZ8aQIQAlNUwjXAN7qw740A2anmx7l2cMDQjCPQpI8eNmi3ehehhFmROy1k3H9zcoierdn_WkePeHU3Q838FE_GHUjqPA926Hmhxg/s2386/05c-Figure-Take%20Another%20LOOK-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1076" data-original-width="2386" height="180" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEggQHx5PCvYKmK_u_pEN0nLGyk_-sOJNah7FN0QB-FiSVEqoYS7UMcBTB9cOy8P2oitVN-prpPz5Had10XMgfWZZBSZ8aQIQAlNUwjXAN7qw740A2anmx7l2cMDQjCPQpI8eNmi3ehehhFmROy1k3H9zcoierdn_WkePeHU3Q838FE_GHUjqPA926Hmhxg/w400-h180/05c-Figure-Take%20Another%20LOOK-USE.png" width="400" /></a></span></span></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></span></span></p><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></div><span style="caret-color: rgb(13, 13, 13); color: #050505; font-family: arial;"><span style="font-family: arial; font-size: medium;"> </span><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjo0wQ8NydpZb7Ws7zOXvd-8bnabDtaEQ5SLQdN_dFkfZ8yWAjWd6xpNlFtEM_lC2e00PEMVs4ADa9QkCoG7ZpsNU-zx1oKTa4UDLdYoBLo1upiNnWzEPzmVqUf_OP_YvVSgUepAWwhaToPq3G8AobXStpft5L8IMkVV2RKKy_r7jFMJ7WNiI4InFwigg/s2482/05aa-%20The%205%20KEY%20Parameters-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1140" data-original-width="2482" height="184" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjjo0wQ8NydpZb7Ws7zOXvd-8bnabDtaEQ5SLQdN_dFkfZ8yWAjWd6xpNlFtEM_lC2e00PEMVs4ADa9QkCoG7ZpsNU-zx1oKTa4UDLdYoBLo1upiNnWzEPzmVqUf_OP_YvVSgUepAWwhaToPq3G8AobXStpft5L8IMkVV2RKKy_r7jFMJ7WNiI4InFwigg/w400-h184/05aa-%20The%205%20KEY%20Parameters-USE.png" width="400" /></a></div><br /></span><p style="caret-color: rgb(13, 13, 13); font-family: arial;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbseza1sg1iQC2OP4J9ow3mtJ_etxCU9haaK6BpH1aojV-j2g_wcX52ZaPS2UcedOKjRen-uxaaV4E0ETTgnvNEg2FlZ3TztcoaNJMeZePgJmdfdEdTRdwLgBUdAJJXHJ01jQkYq-CTM4NMtxNoqf9z1IMBMr1nDrZMVcmIZ8XIfXSYf8egWlUFW2LETU/s3344/5e-%20What%20Next-%20Rhythm%20-%205%20Parameters-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1850" data-original-width="3344" height="221" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjbseza1sg1iQC2OP4J9ow3mtJ_etxCU9haaK6BpH1aojV-j2g_wcX52ZaPS2UcedOKjRen-uxaaV4E0ETTgnvNEg2FlZ3TztcoaNJMeZePgJmdfdEdTRdwLgBUdAJJXHJ01jQkYq-CTM4NMtxNoqf9z1IMBMr1nDrZMVcmIZ8XIfXSYf8egWlUFW2LETU/w400-h221/5e-%20What%20Next-%20Rhythm%20-%205%20Parameters-USE.png" width="400" /></a></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><br /></p><br /><span style="caret-color: rgb(13, 13, 13); font-family: arial; font-size: medium;"><br /></span><p style="caret-color: rgb(13, 13, 13); font-family: arial;"></p><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgBNN8XS9rOIfhVtymuX69TPPiuYhoxFN6St6Q18vfvO4reMWqboyWUdkPHZwXs40mJWX_d_ESZGFXDi_V-iACuEWxLIyRJ0QqzpekhGGROWfQiEAL2kCMSwYMZv350SDu14UlINQg_-3s-uBXo3lpBdr8s0KnOVVGkTkgFZunqw7cyn8uE2bFDvBtcXEY/s3338/06aab-%20Label%20the%20P%20Waves-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1930" data-original-width="3338" height="231" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgBNN8XS9rOIfhVtymuX69TPPiuYhoxFN6St6Q18vfvO4reMWqboyWUdkPHZwXs40mJWX_d_ESZGFXDi_V-iACuEWxLIyRJ0QqzpekhGGROWfQiEAL2kCMSwYMZv350SDu14UlINQg_-3s-uBXo3lpBdr8s0KnOVVGkTkgFZunqw7cyn8uE2bFDvBtcXEY/w400-h231/06aab-%20Label%20the%20P%20Waves-USE.png" width="400" /></a></div><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: justify;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: justify;"><br /></div><br /><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(13, 13, 13); font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6rO47TZ_Moe6shxtzqPyXEsukTDqqhHi_0xDxBXQSNfykKwgs_7BTKLs0pFHnhuo7ZSPrLj_oDGh56Ub5KJvHOdfnjf5WmKhSjA_BnlP1sGlgUuhsU9Guzhd4uthcq7kQ9mlnWwwGkcfL6LmSKV5U3BIZku_t3QTYmKBOHenHNRAf6XxpwmSaIuR5Y8k/s1920/06b-Rhythm-1%20-without%20beats%201,2.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1080" data-original-width="1920" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6rO47TZ_Moe6shxtzqPyXEsukTDqqhHi_0xDxBXQSNfykKwgs_7BTKLs0pFHnhuo7ZSPrLj_oDGh56Ub5KJvHOdfnjf5WmKhSjA_BnlP1sGlgUuhsU9Guzhd4uthcq7kQ9mlnWwwGkcfL6LmSKV5U3BIZku_t3QTYmKBOHenHNRAf6XxpwmSaIuR5Y8k/w400-h225/06b-Rhythm-1%20-without%20beats%201,2.jpg" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> Let's for the moment <u style="font-style: italic;">forget</u> about beats #1 and 2 ...</span></span></td></tr></tbody></table><br /><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8VZ7hHn-U1dXqCzHGxQoLtDtMNYrtm6DveXPJI5H0NA6u4_rwEwaY-t7jewJaLoOPYdivkG_b2xtarnGI9VIswmELP6CHs4qr9UtFSRhK4icJ3vw0WXQpQCrQDoB5M5OH2eD9CV2cZ0M1puUOwei6X5DrNEWh34aTgNFRUWNKNxGvWvNqyNqFp8nG3e4/s2282/06c-The%20AV%20Blocks-1st,2nd,3rd%20degree%20blocks-SMALL.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1374" data-original-width="2282" height="241" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi8VZ7hHn-U1dXqCzHGxQoLtDtMNYrtm6DveXPJI5H0NA6u4_rwEwaY-t7jewJaLoOPYdivkG_b2xtarnGI9VIswmELP6CHs4qr9UtFSRhK4icJ3vw0WXQpQCrQDoB5M5OH2eD9CV2cZ0M1puUOwei6X5DrNEWh34aTgNFRUWNKNxGvWvNqyNqFp8nG3e4/w400-h241/06c-The%20AV%20Blocks-1st,2nd,3rd%20degree%20blocks-SMALL.png" width="400" /></a></div><br /><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><br /></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(13, 13, 13); font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixMxOH-_00Yi2i0ybeHxI9Y-QP-nMeZIWzKy4V9PSyCwWzslrDVQBIoUg-I-48fybWgn3f1hhdjt6ZAy9Ta3w4trH10KiEyrs08xgef9cEs3c_O0nDC_nzjhdyqHGdBjAHWXxHc1YKx9QRwHRdjFN7h3z-lR3dp3p2ov50vJnaNyD-XzrokKK3xWwSxkg/s1364/06-1st-Degree.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="258" data-original-width="1364" height="76" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEixMxOH-_00Yi2i0ybeHxI9Y-QP-nMeZIWzKy4V9PSyCwWzslrDVQBIoUg-I-48fybWgn3f1hhdjt6ZAy9Ta3w4trH10KiEyrs08xgef9cEs3c_O0nDC_nzjhdyqHGdBjAHWXxHc1YKx9QRwHRdjFN7h3z-lR3dp3p2ov50vJnaNyD-XzrokKK3xWwSxkg/w400-h76/06-1st-Degree.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> 1st-degree AV Block — is simply a sinus rhythm with a long PR interval <b>(</b>ie, <i><u>more</u> than 1 large box in duration = >0.20 second</i><b>)</b>.</span></span></td></tr></tbody></table><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><br /></p><br /><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(13, 13, 13); font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlqmKlgIeeFa3aFPYq95zxgUl-uH0qsQgEYcBS4o2-JoZ5QNhX0qha3hyYcgpIfUCZ4_8V2ZQaYuPhe8q9aozryv3-aLbYBQCGksd3VXobTtIIFVYc9N7fanH_xuFr_SJFnLugUbG613zzdk-zzQjtlha53o92DhVG_wkAB_o-BNO_fXDEXnbE-3HOA4I/s1358/08b-2nd-Degree%20AV%20Blocks.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="590" data-original-width="1358" height="174" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhlqmKlgIeeFa3aFPYq95zxgUl-uH0qsQgEYcBS4o2-JoZ5QNhX0qha3hyYcgpIfUCZ4_8V2ZQaYuPhe8q9aozryv3-aLbYBQCGksd3VXobTtIIFVYc9N7fanH_xuFr_SJFnLugUbG613zzdk-zzQjtlha53o92DhVG_wkAB_o-BNO_fXDEXnbE-3HOA4I/w400-h174/08b-2nd-Degree%20AV%20Blocks.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="color: #0d0d0d; font-family: arial; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; font-family: arial; text-align: justify;"> The 3 types of 2nd-degree AV block.</span></span></td></tr></tbody></table><p style="caret-color: rgb(13, 13, 13); font-family: arial;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><br /></p><span style="caret-color: rgb(13, 13, 13); font-family: arial; font-size: medium;"><br /></span><p style="caret-color: rgb(13, 13, 13); font-family: arial;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(13, 13, 13); font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjveeAKROE_Sbtco2OLS5DMq8kDxzQ5ADOECqn-ncdnOJDEGGxZ0_-rr8hzgtL0oO5VP1_dMtLd8W2ryZ1o-KmYcSeV7LrYQREt8wKX3qzyU1IVsEHbfH9L60hQEoTzqt0o5PEEfaTOY1OxiYPMDVuyThQjuHRoot9Wevn6SuWMET2rbHKBIxMgobYh5HI/s1360/08c-2-1%202nd%20Degree.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="276" data-original-width="1360" height="81" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjveeAKROE_Sbtco2OLS5DMq8kDxzQ5ADOECqn-ncdnOJDEGGxZ0_-rr8hzgtL0oO5VP1_dMtLd8W2ryZ1o-KmYcSeV7LrYQREt8wKX3qzyU1IVsEHbfH9L60hQEoTzqt0o5PEEfaTOY1OxiYPMDVuyThQjuHRoot9Wevn6SuWMET2rbHKBIxMgobYh5HI/w400-h81/08c-2-1%202nd%20Degree.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="color: #0d0d0d; font-family: arial; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; font-family: arial; text-align: justify;"> 2nd-degree AV block with 2:1 AV conduction.</span></span></td></tr></tbody></table><br /><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(13, 13, 13); font-family: arial; margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpxFuXSjFbRiGk10OsF775jVoJZTGAY5w94T2y5KowwHd74ujypsL9JrCLwsYLkkf_3SIi8zyZbBeS-hOhqDmbeQgAHU-akxvarUmMRcu4Py34_FFVrdt5dwdHFwB-uQy2sTpU0In_Rkq1tJ6sfcXXSSFKcWqgV_VUorZ2ucg_pQeGLvCIJ_wA3hjZthA/s1338/08d-3rd-Degree.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="272" data-original-width="1338" height="81" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgpxFuXSjFbRiGk10OsF775jVoJZTGAY5w94T2y5KowwHd74ujypsL9JrCLwsYLkkf_3SIi8zyZbBeS-hOhqDmbeQgAHU-akxvarUmMRcu4Py34_FFVrdt5dwdHFwB-uQy2sTpU0In_Rkq1tJ6sfcXXSSFKcWqgV_VUorZ2ucg_pQeGLvCIJ_wA3hjZthA/w400-h81/08d-3rd-Degree.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="caret-color: rgb(0, 0, 0); color: #0d0d0d; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="caret-color: rgb(0, 0, 0); color: #050505; font-family: arial; text-align: justify;"> 3rd-degree AV block with ventricular escape.</span></span></td></tr></tbody></table><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: justify;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: justify;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: justify;">=======================================================</div><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: justify;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: justify;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: justify;"><br /></div><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: justify;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmiJLG8bNsGEVs5rkz5IqgMOjjU3vxSqZ60Rs1YdUrYsxKrpc_BSjYu_s483BmNHz8QbcAuaJFOmyjuRnikOjU26gzM76zkfQiKz6n4PyzfA1lhN_hiJxdweWxsL5h1BFnXtMEPe2zkUyqVSI7ySfInigzIO_igQ0jGGL4RY65-BZMWn0MFtmVfYb4GlY/s2148/08a-Back%20to%20Today's%20Tracing-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="742" data-original-width="2148" height="139" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhmiJLG8bNsGEVs5rkz5IqgMOjjU3vxSqZ60Rs1YdUrYsxKrpc_BSjYu_s483BmNHz8QbcAuaJFOmyjuRnikOjU26gzM76zkfQiKz6n4PyzfA1lhN_hiJxdweWxsL5h1BFnXtMEPe2zkUyqVSI7ySfInigzIO_igQ0jGGL4RY65-BZMWn0MFtmVfYb4GlY/w400-h139/08a-Back%20to%20Today's%20Tracing-USE.png" width="400" /></a></div><br /><span style="font-family: arial; font-size: medium;"><br /></span><p></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><br /></div><br /><span style="font-family: arial; font-size: medium;"><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td style="text-align: justify;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEim0kBvBWQtQd82nG98iedzezYePGq7BJh47cdB-rSXLnRf07ssG0cGuTwe3iwXwqrTqI6uJwqfrCqyLObLgXT68dTJChom1qOYQW_X5-qquk-ITgpwcFfE35e49l1si49SLMT53xd628-ra_zFKZPjWyd-xxUWzi-2ego3Bt2EbQrx8ohWkNOUtSYk/s3320/Figure-1%20%20Lead%20II%20(11-1.21-2022)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="618" data-original-width="3320" height="75" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEim0kBvBWQtQd82nG98iedzezYePGq7BJh47cdB-rSXLnRf07ssG0cGuTwe3iwXwqrTqI6uJwqfrCqyLObLgXT68dTJChom1qOYQW_X5-qquk-ITgpwcFfE35e49l1si49SLMT53xd628-ra_zFKZPjWyd-xxUWzi-2ego3Bt2EbQrx8ohWkNOUtSYk/w400-h75/Figure-1%20%20Lead%20II%20(11-1.21-2022)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: justify;"><br /><br /><br /></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"></span></span><p></p></div><div style="caret-color: rgb(13, 13, 13); font-family: arial; text-align: justify;"><br /></div><br /><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrAyeHXVNQyGA8WujaZqFxYaI3Q6ujWx75p30ds7vlIml-Q2OLGh4NESplDTP2Q4tRkCig1Gf6sRCtn0gbLWtEX-HArJHeZVQiDdMA4LcY9aGlKgF7rG1QFC7ifVqvlKz0OKQlyRHOQXoQLaLIrf72sjcQ9xkqZgh63hORz_zlTlBWkhpp4vgJt9OzuSY/s2120/09-%20The%20Laddergram-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="468" data-original-width="2120" height="71" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgrAyeHXVNQyGA8WujaZqFxYaI3Q6ujWx75p30ds7vlIml-Q2OLGh4NESplDTP2Q4tRkCig1Gf6sRCtn0gbLWtEX-HArJHeZVQiDdMA4LcY9aGlKgF7rG1QFC7ifVqvlKz0OKQlyRHOQXoQLaLIrf72sjcQ9xkqZgh63hORz_zlTlBWkhpp4vgJt9OzuSY/s320/09-%20The%20Laddergram-USE.png" width="320" /></a></div><span style="caret-color: rgb(13, 13, 13); font-family: arial; font-size: medium;"><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><br /></span><p style="caret-color: rgb(13, 13, 13); font-family: arial;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgAkk1Y1z5ueNoPTnWeuIwhcrpYFpYSHnyCbFxNSggvZKc3vNsVPPPDiFTbbsa24hE1rPhSFdx-Myt19uOuymkVTwxLqP2Ymp0FR_WU8hci0GzRYh9yTSm07eCU612Rvkuku77fBIGt3vcr-Iyt2qtzMWEn6TmHyOD7_5OcVtLVecKn-8lD9gjzHK6pXw/s3348/Figure-4%20Ladder-1.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1412" data-original-width="3348" height="169" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhgAkk1Y1z5ueNoPTnWeuIwhcrpYFpYSHnyCbFxNSggvZKc3vNsVPPPDiFTbbsa24hE1rPhSFdx-Myt19uOuymkVTwxLqP2Ymp0FR_WU8hci0GzRYh9yTSm07eCU612Rvkuku77fBIGt3vcr-Iyt2qtzMWEn6TmHyOD7_5OcVtLVecKn-8lD9gjzHK6pXw/w400-h169/Figure-4%20Ladder-1.png" width="400" /></a></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1420" data-original-width="3346" height="170" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhP7KUnG4pSC70hVhuc5RoPWT_zC9jd9knls4eGJZlxPxZ_nmXKeEzIwYCM2wuf1WqOuk9WGbJr8XTd5LJQNldYC0YB5l0_95rcW9_g1gENewN9QOMUymnS0u0eTHDko1Nm6_mtMqSU02U7TGcn9UL9Y_A8Y4nqPrWKEFodShJ3TMN6InnkykFZq092dOo/w400-h170/Figure-5%20Ladder-2.png" style="caret-color: rgb(13, 13, 13); color: #0000ee; text-align: center; text-decoration: underline;" width="400" /></span></p><div style="caret-color: rgb(13, 13, 13); font-family: arial;"><span style="font-family: arial; font-size: medium;"><br /></span></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in; text-align: center;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1YwNX4Pgn2HbCNcLCEN20_vF-M0zgHzIa9FFUfC5qlvgirrxgeaNQRYghKydgXM0uJLyUBJYWO8_kZvEmNq7M_H_m3OYDuJWlFQUHxiAtgJ69Dng8fcWG6wIV9CKJvZVRn52XfEkNwBU/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1YwNX4Pgn2HbCNcLCEN20_vF-M0zgHzIa9FFUfC5qlvgirrxgeaNQRYghKydgXM0uJLyUBJYWO8_kZvEmNq7M_H_m3OYDuJWlFQUHxiAtgJ69Dng8fcWG6wIV9CKJvZVRn52XfEkNwBU/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; color: #050505; font-family: -webkit-standard; text-align: justify;"><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;">==================================</span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><div style="text-align: justify;"><b style="font-family: arial;"><u><i><span style="color: red;">A</span>dditional</i> <span style="color: red;">M</span>aterial on <i><span style="color: red;">T</span>oday's</i> <span style="color: red;">C</span>ASE:</u></b></div><div style="text-align: justify;"><b style="font-family: arial;"><u><br /></u></b></div></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(0, 0, 0); margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td><div class="separator" style="clear: both;"><a href="https://dl.dropboxusercontent.com/s/p5o4fsrvt6mzqv3/z-ECG%20Audio%20Pearl-4%20%282-12.1-2021%29-USE-Faster.m4a?dl=0" target="_blank"><span style="font-family: arial; font-size: medium;">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1470" data-original-width="2048" height="288" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUAcJgawC2j9KDwKlACfTSKiiFHIo_a9sS0f1ZnbphiPfeBWj2mSS913KvLr_WX6iCOOpF-G8Bprw20u8pN73MMgyBaMr4Q21EXsDMgYLbRZSWW-bKbUSMQjiEFEj72JNPtxlA1iLfHe8/w400-h288/MP-4+%2528186%2529-Suspect+Mobitz+I-USE.png" width="400" /></span> —</span></a></div><span style="font-family: arial; font-size: medium;"><br /></span></td></tr><tr><td class="tr-caption"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span><span>4</span></u></b><b style="text-align: justify;"> (</b><i><span style="text-align: justify;">4:3</span><span style="text-align: justify;">0</span></i><i style="text-align: justify;"> minutes <b><u>Audio</u></b></i><b style="text-align: justify;">)<span style="color: red;">:</span></b><span style="text-align: justify;"> — takes a brief look at the <b>AV Blocks</b> — and focuses on <i>WHEN</i> to <i>suspect</i> <b>Mobitz I</b>.</span></span></td></tr></tbody></table><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><br /></p><div style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://www.dropbox.com/s/v01yvlqafd5c6z2/AV%20Blocks-Pg%2060-66%20ECG-PB%20%281-16.22-2021%29-USE.pdf?dl=0" target="_blank">Section 2F</a> (</b><i>6 pages = the <b>"<u>short</u>" Answer</b></i><b>)</b> from my ECG-2014 Pocket Brain book provides quick written review of the <b>AV Blocks (</b><i>This is a free download</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><span><b><a href="https://www.dropbox.com/s/k1jk1y4o4uu48ab/20.0-%20ACLS-2013-e-PUB-AV%20Block-Dissociaton-%2810-15.11-2014%29-LOCK.pdf?dl=0" target="_blank">Section 20</a></b> </span><b>(</b><i>54</i><i> pages = the <b>"<u>long</u>" Answer</b></i><b>)</b> from my ACLS-2013-Arrhythmias <i>Expanded</i> Version provides <i>detailed</i> discussion of <i>WHAT</i> the <b>AV Blocks</b> are — and what they are <u>not</u>! </span>(<i>This is a free download</i>).</li></ul></div></span></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;">=======================<o:p></o:p></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><i><u>Related</u></i></b><b><u> ECG Blog Posts to <i>Today’s</i> Case:</u> </b></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"></p><ul style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — Review of the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach</b> for systematic rhythm interpretation.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> <b><i>draw</i></b> <b>L</b></span><b style="font-family: arial;">addergrams (</b><i style="font-family: arial;">with LINKS to more than 50 laddergram cases — many with step-by-step sequential illustration</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2019/05/ecg-blog-164-pacs-blocked-pacs.html" target="_blank">ECG Blog #164</a></b> — Which reviews <i>step-by-step</i> the diagnosis of a <b>Mobitz I 2nd-degree AV block (</b><i>with sequential laddergram illustration</i><b>)</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2019/09/ecg-blog-168-stemi-complex-av-block.html" target="_blank">ECG Blog #168</a></b> — A complex <b><i>dual-level </i>AV Wenckebach (</b><i>Laddergram</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2018/07/ecg-blog-154-stemi-inferior-mobitz.html" target="_blank">ECG Blog #154</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2012/11/ecg-interpretation-review-55-mobitz-i.html" target="_blank">ECG Blog #55</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2021/05/the-12-lead-ecg-and-long-lead-ii-rhythm.html" target="_blank">ECG Blog #224</a></b> and <b><a href="https://ecg-interpretation.blogspot.com/2021/06/ecg-blog-232-47-what-is-bigeminy.html" target="_blank">ECG Blog #232 </a></b>— <b><i>Acute</i> MI</b> with <b>AV Wenckebach</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2013/03/ecg-interpretation-review-63-av-block.html" target="_blank">ECG Blog #63</a></b> — <b>Mobitz I</b> with <b>Junctional <i>Escape</i> Beats</b>.</span></li></ul><p style="caret-color: rgb(0, 0, 0); color: black; text-align: left;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><div class="separator" style="caret-color: rgb(0, 0, 0); clear: both; color: black; text-align: center;"><span style="font-family: arial; font-size: medium; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgToTJ6lth3lK5od4oIJM19G0r2sow_0nRRUfJIWtbXsVgI9VRfD_2l6pDgP7KomUFRc9OxYFCdMVG557HCCvVB_1UBm2WrVZA2bq_4rZu3uIWAFGZUsD8V-_ZempjCZoodyin28DOEj7Y/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgToTJ6lth3lK5od4oIJM19G0r2sow_0nRRUfJIWtbXsVgI9VRfD_2l6pDgP7KomUFRc9OxYFCdMVG557HCCvVB_1UBm2WrVZA2bq_4rZu3uIWAFGZUsD8V-_ZempjCZoodyin28DOEj7Y/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><br /></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><span style="caret-color: rgb(0, 0, 0); color: black; font-family: arial; font-size: medium; text-align: left;"><div style="text-align: center;"> </div></span></div><div class="separator" style="caret-color: rgb(13, 13, 13); clear: both; font-family: arial; text-align: center;"><br /></div><br /></span></span></div><div style="text-align: justify;"><br /></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-43275027670800327212023-11-11T00:00:00.002-05:002023-11-16T19:14:32.600-05:00ECG Video Blog #403 (220) — Ps,Qs,3Rs Approach to this Tachycardia ...<div style="text-align: justify;"><br /></div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;">======================================</span></span></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span><span style="font-family: arial; font-size: medium;"><span style="color: #050505;"> —</span><i style="color: #050505;"> </i><b style="color: #050505;"><a href="https://www.youtube.com/watch?v=2NW7i4YqI7o" target="_blank">CLICK HERE</a></b><i style="color: #050505;"> — for a </i><u style="font-weight: bold;"><span style="color: red;">V</span><span style="color: #050505;">ideo</span></u><span style="color: #050505;"> presentation of this case! (<i>22 minutes</i>)</span></span></span></p><p class="MsoNormal" style="margin: 0in;"></p><ul><li><span style="color: #050505;"><span style="caret-color: rgb(5, 5, 5);">Below are slides used in my video presentation.</span></span></li><li><span style="color: #050505;"><span style="caret-color: rgb(5, 5, 5);">For full discussion of this case — <i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-220-ecg-mp-37-vt-or-aberrancy.html" target="_blank">ECG Blog #220</a> </b>—</span></span></li></ul><p></p><p class="MsoNormal" style="font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;">======================================</span></span></p><div><br /></div></div></span><div><span style="font-family: arial; font-size: medium;"><span style="background-color: white; caret-color: rgb(13, 13, 13); white-space: pre-wrap;"><div style="text-align: justify;"><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;">The long lead II rhythm strip shown in <b><u>Figure-1</u></b> was obtained from an 51-year-old man who presented to the ED (<i>Emergency Department</i>) with "palpitations" that began 1 hour earlier.<o:p></o:p></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"></p><ul style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i><span style="color: #050505;">HOW </span></i><span style="color: #050505;">would you interpret this tracing?</span></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><u><span style="color: #050505;">Clinically</span></u><span style="color: #050505;"> — <i>What would YOU do?</i></span></span></li></ul><p style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; text-align: left;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(0, 0, 0); color: #0d0d0d; font-family: -webkit-standard; margin-left: auto; margin-right: auto; text-align: justify;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgl1buVN6wZw7eDZuEUArlwEs8jpIfjOUgsjuMv1dVpxsELvWV9MBhX0KXcJPF3ZjqLc4yOt08Q3Cr8egu1822wSLVGpNUm_HVYNdsvzEl3YCvK5Uqy_EfeddIR9nk10H5k9J4zn-e9AKg/s3610/Figure-1++Lead+II+in+ED+%25284-28.21-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="864" data-original-width="3610" height="96" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgl1buVN6wZw7eDZuEUArlwEs8jpIfjOUgsjuMv1dVpxsELvWV9MBhX0KXcJPF3ZjqLc4yOt08Q3Cr8egu1822wSLVGpNUm_HVYNdsvzEl3YCvK5Uqy_EfeddIR9nk10H5k9J4zn-e9AKg/w400-h96/Figure-1++Lead+II+in+ED+%25284-28.21-2021%2529-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #050505;">Figure-1:</span></u></b><span style="color: #050505; text-align: justify;"> Long lead II rhythm strip, obtained from an 51-year-old man with palpitations.</span></span></td></tr></tbody></table><span style="caret-color: rgb(0, 0, 0); color: black; font-family: arial; font-size: medium; text-align: left;"><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div></span><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnCa5XfMmZiNBwOj-1gO7J00BujfSWhyphenhyphenejI_Fz07CXe-WjWzjfkZ4vep7iEk8F60QK3ImLLX26RNKif-cHbxQjyctqB9J_pgy3GkV9ebt3FV7gMiT1SWcrLU2w24e33LtqNAVsVqDLUmzEz9GzFLJx6v9T75a8THZog4cZhMlZsYrWzf1fpB4SJyhgQ6M/s1664/02a-%20The%20Most%20Common%20Oversight.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="890" data-original-width="1664" height="214" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnCa5XfMmZiNBwOj-1gO7J00BujfSWhyphenhyphenejI_Fz07CXe-WjWzjfkZ4vep7iEk8F60QK3ImLLX26RNKif-cHbxQjyctqB9J_pgy3GkV9ebt3FV7gMiT1SWcrLU2w24e33LtqNAVsVqDLUmzEz9GzFLJx6v9T75a8THZog4cZhMlZsYrWzf1fpB4SJyhgQ6M/w400-h214/02a-%20The%20Most%20Common%20Oversight.png" width="400" /></a></div><div class="separator" style="clear: both; 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text-align: center;"><br /></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkBwStZToiVjQgNtzyxpnJJVVa58VFOi892f3riQmKFJQD_gdnWv4k8dhmWPqCHoOjjkhljDRgQGPs72ohQ0vK_09_Khnhz1ul8Y4DsgMuLNYavfOJ2G3DXpqgiAXCSbVjqeAZ64X1xSsAoc326XRfw1kXBehLqJd7_bPh5XDuD4PL31a6hygbZFkSSu8/s2052/The%20System%20I%20Favor%20for%20Rhythm%20Interp-2-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="776" data-original-width="2052" height="151" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhkBwStZToiVjQgNtzyxpnJJVVa58VFOi892f3riQmKFJQD_gdnWv4k8dhmWPqCHoOjjkhljDRgQGPs72ohQ0vK_09_Khnhz1ul8Y4DsgMuLNYavfOJ2G3DXpqgiAXCSbVjqeAZ64X1xSsAoc326XRfw1kXBehLqJd7_bPh5XDuD4PL31a6hygbZFkSSu8/w400-h151/The%20System%20I%20Favor%20for%20Rhythm%20Interp-2-USE.png" width="400" /></a></div><div style="text-align: justify;"><br /></div><p></p><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="-webkit-text-stroke-width: 0px; caret-color: rgb(0, 0, 0); color: #0d0d0d; font-family: -webkit-standard; margin-left: auto; margin-right: auto; orphans: auto; widows: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvshp7TNcNBjqv69SKorVvT-qBtr4Fl0WSSGzvbmxcVTmWaNgRym5sWkIzYnxXOUeZFN1BuiMYZq2_i08UzSsgW91Zi4IJ0PQ6oGx9FfGEDg_9C80gKU44oNdWwIEn2l73RzGyXxNpmN2zFUVh9c9MMEqEd1DFQMryQcFAqqj8KahM1HS6qiKIlI5xhuw/s2422/Ps,%20Qs,%203R%20Approach-%20from%20185-%20for%20220.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="2156" data-original-width="2422" height="356" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhvshp7TNcNBjqv69SKorVvT-qBtr4Fl0WSSGzvbmxcVTmWaNgRym5sWkIzYnxXOUeZFN1BuiMYZq2_i08UzSsgW91Zi4IJ0PQ6oGx9FfGEDg_9C80gKU44oNdWwIEn2l73RzGyXxNpmN2zFUVh9c9MMEqEd1DFQMryQcFAqqj8KahM1HS6qiKIlI5xhuw/w400-h356/Ps,%20Qs,%203R%20Approach-%20from%20185-%20for%20220.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; font-family: arial; text-align: justify;"> The <b><u>P</u></b>s, <b><u>Q</u></b>s, <b>3<u>R</u> Approach</b> to Rhythm Interpretation.</span></span></td></tr></tbody></table><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"> </span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhjwElXkNaf0Q94_nYOZbGpQaz4icnK47cmkQv9DL_MQAu7nHd58jx2Fr4B31MKerWkNIFoO2JKuqozZghQLXJqF13Zg1I07ofBQ4ZmImi9DiuQZiwfrGf4UN_5Gtm-SG_4nwoSyQbrD-Sp09blstetR0Q8cBMP45HSB8W-4olX9xMLtyH09x5ueGfoiX4/s3182/04-%20Figure-1%20-%20in%20Blog%20220-Lead%20II%20Rhythm.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="752" data-original-width="3182" height="95" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhjwElXkNaf0Q94_nYOZbGpQaz4icnK47cmkQv9DL_MQAu7nHd58jx2Fr4B31MKerWkNIFoO2JKuqozZghQLXJqF13Zg1I07ofBQ4ZmImi9DiuQZiwfrGf4UN_5Gtm-SG_4nwoSyQbrD-Sp09blstetR0Q8cBMP45HSB8W-4olX9xMLtyH09x5ueGfoiX4/w400-h95/04-%20Figure-1%20-%20in%20Blog%20220-Lead%20II%20Rhythm.png" width="400" /></a></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh7vQCRCjTpBzw2ks57IK6GZBwvUvBFt3fA7zoi-c88H1PmnqRF8icIQHR-J3TgK8jqNAtfzSH7VVoT7ddeK7ix87hneMZAYtH9HZUMXgq26jk_1UJZm9rKuyVctPGFuOUfRsu5Lakb4ZsrlMxd2Tp_Sahon2VWhmYCPRmeRm1xpIMabwLSooMPQzaYZKg/s2856/05-%20Neither%20VT%20nor%20SVT%20is%20Best%20Answer.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1754" data-original-width="2856" height="246" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh7vQCRCjTpBzw2ks57IK6GZBwvUvBFt3fA7zoi-c88H1PmnqRF8icIQHR-J3TgK8jqNAtfzSH7VVoT7ddeK7ix87hneMZAYtH9HZUMXgq26jk_1UJZm9rKuyVctPGFuOUfRsu5Lakb4ZsrlMxd2Tp_Sahon2VWhmYCPRmeRm1xpIMabwLSooMPQzaYZKg/w400-h246/05-%20Neither%20VT%20nor%20SVT%20is%20Best%20Answer.png" width="400" /></a></div><br /><span style="font-family: arial; font-size: medium;"><br /></span><p></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhxA4f6Pv-OWb8Hw1uGT0BK2T8DziLUwT_J1eIZp3_gP3fja1MW5KV2eYC1MJ4FOXXEESGZiLnUFOjP0K2QF_ln9sIcf24N_-l1TxTN2Pd0M3PVQm9rwEOEV7jeyfcNvylWwE7atjMWFFiZmxAk8SkvSt5Z9FpILChIxjJqKPjdKnojcgYEATDvAfuGyiI/s2986/06b-%20Is%20the%20QRS%20Wide-Half%20Large%20Box.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1694" data-original-width="2986" height="228" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhxA4f6Pv-OWb8Hw1uGT0BK2T8DziLUwT_J1eIZp3_gP3fja1MW5KV2eYC1MJ4FOXXEESGZiLnUFOjP0K2QF_ln9sIcf24N_-l1TxTN2Pd0M3PVQm9rwEOEV7jeyfcNvylWwE7atjMWFFiZmxAk8SkvSt5Z9FpILChIxjJqKPjdKnojcgYEATDvAfuGyiI/w400-h228/06b-%20Is%20the%20QRS%20Wide-Half%20Large%20Box.png" width="400" /></a></div><br /><span style="font-family: arial; font-size: medium;"><br /><br /></span><p></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUVPH_W2Gq00-lKRrqEipM27IGiP1Ape3yYpwACRggC6Ou_Np5cN_qZJckWdmfJP092MsCYgHcKNnFsUC1lOB_oN5QjXTexQUn-gdee8aEKlcOb_xeLk_WforeFweP8cgTTmEb0oc2gTIjyBpzxMN3Xovtr7GOQqWBS_mM9fIl8InA6_YT1Dlu2Zd7TxU/s1564/The%20Every-Other-Beat%20Method-2-USE.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="742" data-original-width="1564" height="190" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgUVPH_W2Gq00-lKRrqEipM27IGiP1Ape3yYpwACRggC6Ou_Np5cN_qZJckWdmfJP092MsCYgHcKNnFsUC1lOB_oN5QjXTexQUn-gdee8aEKlcOb_xeLk_WforeFweP8cgTTmEb0oc2gTIjyBpzxMN3Xovtr7GOQqWBS_mM9fIl8InA6_YT1Dlu2Zd7TxU/w400-h190/The%20Every-Other-Beat%20Method-2-USE.png" width="400" /></a></div><br /><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnZljhYaawrsx_2BuCpG7xyMTLdd5aSX8AKYq_TvjMldEHXhyF9GswnuI5JGyabYWI_PmqJomCVgfhzLXg_Ua0iF9PIbpNrnxj7zP56EVi6bfCl4YX0MUOfUqF1_2YDcP7Ffsd0cW8uGJ4qs3DjZYM3_CeCqzppzO1m2FQrFTQ1p1-lH10VwHe0dQ9ufM/s1920/06d-More%20than%20Half%20a%20Large%20Box.jpg" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1080" data-original-width="1920" height="225" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhnZljhYaawrsx_2BuCpG7xyMTLdd5aSX8AKYq_TvjMldEHXhyF9GswnuI5JGyabYWI_PmqJomCVgfhzLXg_Ua0iF9PIbpNrnxj7zP56EVi6bfCl4YX0MUOfUqF1_2YDcP7Ffsd0cW8uGJ4qs3DjZYM3_CeCqzppzO1m2FQrFTQ1p1-lH10VwHe0dQ9ufM/w400-h225/06d-More%20than%20Half%20a%20Large%20Box.jpg" width="400" /></a></div><br /><p></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in; text-align: center;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"> </span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><p style="font-family: -webkit-standard; text-align: left;"></p><p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="-webkit-text-stroke-width: 0px; caret-color: rgb(13, 13, 13); color: #050505; font-family: -webkit-standard; letter-spacing: normal; margin-left: auto; margin-right: auto; text-align: center; text-decoration: none; text-transform: none; word-spacing: 0px;"><tbody><tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXCctvVFX5r2zL5hD_zfA9mEeGrfdf8243T7s9ak1euSmISNo6EvrnKBZ1r3D-j5kh93ebsZV1MF934Jr7_U0wgWF3rgYvejawQxqL9-AwE2_X4HAF8a9yt4NQNElCW-H8kAhHIBT14ws/s3610/Figure-2++Lead+II+in+ED-RATE+%25284-28.21-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="864" data-original-width="3610" height="96" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXCctvVFX5r2zL5hD_zfA9mEeGrfdf8243T7s9ak1euSmISNo6EvrnKBZ1r3D-j5kh93ebsZV1MF934Jr7_U0wgWF3rgYvejawQxqL9-AwE2_X4HAF8a9yt4NQNElCW-H8kAhHIBT14ws/w400-h96/Figure-2++Lead+II+in+ED-RATE+%25284-28.21-2021%2529-USE.png" style="cursor: move;" width="400" /></span></a></td></tr><tr><td class="tr-caption"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; text-align: justify;"> I've labeled <u>Figure-1</u> to illustrate estimation of <b>heart rate (</b><i>by the "every-third-beat" Method</i><b>)</b> — <u>and</u> — assessment of <b>QRS duration (</b><i>the solid PURPLE box showing that onset and offset of the QRS measures at least 0.12 second</i><b>)</b>.</span></span></td></tr></tbody></table><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjCumF5NRCITuDdHR-BvuCbD5xU7lAF80NDcb2r6SpaWcWvDz02BlrJPZe0FYry-zAIVLA8UYkUw_0cawlLjCkuM1EKumZL1ycY_sNIq1ijEBgv6Kc1BPnWFq-U71oN1kYCX1wxg63FB8_ACxSs50dQRFyXwmKBR8vC3DR6nC9LFRYUXOTklSoBTSgq2jQ/s1736/Differential%20Dx%20of%20Regular%20WCT.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="540" data-original-width="1736" height="125" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjCumF5NRCITuDdHR-BvuCbD5xU7lAF80NDcb2r6SpaWcWvDz02BlrJPZe0FYry-zAIVLA8UYkUw_0cawlLjCkuM1EKumZL1ycY_sNIq1ijEBgv6Kc1BPnWFq-U71oN1kYCX1wxg63FB8_ACxSs50dQRFyXwmKBR8vC3DR6nC9LFRYUXOTklSoBTSgq2jQ/w400-h125/Differential%20Dx%20of%20Regular%20WCT.png" width="400" /></a></div><div style="text-align: justify;"><br /></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><div class="separator" style="clear: both; color: #0d0d0d; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0wNsKci0Xh-ysYS48N9yEkf4LCP859_EDZ0rY8gjeeozFNZc1M0vmW0IfHXyZpiLsUs0WpAq0VhCHFadruGYA5ja9Wy7CAcw4MGpZRpALd7HMLwskpwJO2K3QCWU1mdPS0rwPrhjaoZfVKB0lFRs4siufl5GR_vZ67wpCoHmg69hUx9hWvOvbqS8Iw7A/s1720/09-Diff%20Dx%20of%20Regular%20WCT.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1106" data-original-width="1720" height="258" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi0wNsKci0Xh-ysYS48N9yEkf4LCP859_EDZ0rY8gjeeozFNZc1M0vmW0IfHXyZpiLsUs0WpAq0VhCHFadruGYA5ja9Wy7CAcw4MGpZRpALd7HMLwskpwJO2K3QCWU1mdPS0rwPrhjaoZfVKB0lFRs4siufl5GR_vZ67wpCoHmg69hUx9hWvOvbqS8Iw7A/w400-h258/09-Diff%20Dx%20of%20Regular%20WCT.png" width="400" /></a></div><div style="color: #0d0d0d; text-align: justify;"><br /></div><div style="color: #0d0d0d; text-align: justify;"><br /></div><br /><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><div class="separator" style="clear: both; color: #0d0d0d; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgvvHhc7igLdQZQDfNS7w6PX7W-6a1pJe2MI5j3sjQ39ipTqYrFwgtu2HuOrSwszJV6X4ZjupKIsrBhY4qY-12zJDDY6YpmPNi4NKOU4snglb0anCksidUdRrsGWzR9bBLlBVwzomCgpjlqIaCSU2QtFnnh9s2oN2intTei8DCcEGK-Syr1DsMvkuKdaFk/s2856/15-%20Can%20I%20Get%20Beyond%2090%20per%20cent%20Likelihood.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1754" data-original-width="2856" height="246" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgvvHhc7igLdQZQDfNS7w6PX7W-6a1pJe2MI5j3sjQ39ipTqYrFwgtu2HuOrSwszJV6X4ZjupKIsrBhY4qY-12zJDDY6YpmPNi4NKOU4snglb0anCksidUdRrsGWzR9bBLlBVwzomCgpjlqIaCSU2QtFnnh9s2oN2intTei8DCcEGK-Syr1DsMvkuKdaFk/w400-h246/15-%20Can%20I%20Get%20Beyond%2090%20per%20cent%20Likelihood.png" width="400" /></a></div><br /><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in; text-align: center;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"> </span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><b><span style="font-family: arial; font-size: medium;"></span></b></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"></p><p style="text-align: left;"></p><p></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="-webkit-text-stroke-width: 0px; caret-color: rgb(13, 13, 13); color: #050505; font-family: -webkit-standard; letter-spacing: normal; margin-left: auto; margin-right: auto; text-align: center; text-decoration: none; text-transform: none; word-spacing: 0px;"><tbody><tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMvxp3uInw_UUnXv_myFa8mOCYUg3T1jgBp6MjdRcs-lgqufPY34V207clCU2ey-PRMtZ_6HMLPgcal98HWEsMJrZtr3LYEuF8kAzlDTr6-E2CYBJx4MSl07Rat9oSRIpgxt3HrtQLMks/s2048/Figure-3++ECG-1+in+ED+%25284-23.21-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1086" data-original-width="2048" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjMvxp3uInw_UUnXv_myFa8mOCYUg3T1jgBp6MjdRcs-lgqufPY34V207clCU2ey-PRMtZ_6HMLPgcal98HWEsMJrZtr3LYEuF8kAzlDTr6-E2CYBJx4MSl07Rat9oSRIpgxt3HrtQLMks/w400-h213/Figure-3++ECG-1+in+ED+%25284-23.21-2021%2529-USE.png" style="cursor: move;" width="400" /></span></a></td></tr><tr><td class="tr-caption"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; text-align: justify;"> 12-lead ECG obtained from an 51-year-old man with palpitations.</span></span></td></tr></tbody></table><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in; text-align: left;"><span style="font-family: arial; font-size: medium;"></span></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(0, 0, 0); color: #0d0d0d; font-family: -webkit-standard; margin-left: auto; margin-right: auto; text-align: justify;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiWTSL32BJAjxVvQbxqLv5GgJUbW6pMm6LemSwljx8-1KnWV77UbCnooNRKPM6-CHGX0I3rLXzVOhsNLCj9cARFDDFdwHhbtz9eUWV4ehco4VPooif9s4PJrtWE4I0T80aAhyMpceIv9oA/s2048/Figure-6++3+Simple+Rules+%25284-29.21-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1345" data-original-width="2048" height="263" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiWTSL32BJAjxVvQbxqLv5GgJUbW6pMm6LemSwljx8-1KnWV77UbCnooNRKPM6-CHGX0I3rLXzVOhsNLCj9cARFDDFdwHhbtz9eUWV4ehco4VPooif9s4PJrtWE4I0T80aAhyMpceIv9oA/w400-h263/Figure-6++3+Simple+Rules+%25284-29.21-2021%2529-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; text-align: justify;"> Use of the <b><i>"3 <u>Simple</u> Rules"</i></b> for distinction between SVT <u>vs</u> VT <b>(</b><i>taken from</i><b> </b></span><b style="text-align: justify;"><span style="color: #050505;"><a href="https://ecg-interpretation.blogspot.com/2021/02/blog-196-ecg-mp-13-is-this-vt-or-svt.html" target="_blank">ECG Blog #196</a></span></b><b style="text-align: justify;"><span style="color: #050505;">)</span></b><span style="color: #050505; text-align: justify;">.</span></span></td></tr></tbody></table><p style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; text-align: left;"></p><div style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard;"><span style="font-family: arial; font-size: medium;"> </span></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="caret-color: rgb(0, 0, 0); color: black; font-family: arial; font-size: medium; text-align: left;"></span></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(0, 0, 0); color: #0d0d0d; font-family: -webkit-standard; margin-left: auto; margin-right: auto; text-align: justify;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh9TOWaTmOfqGuDUiKWb0eDjnKR2BK67iht_KgRu-w8z-LklZPJR6qv_tB8wHf-yeLYIEfqNUM06GqjQhC60sFveMAJv_JtuvmlIR97P3mDkecZltnrZTa88iRuhioOR0N-4j3wiWw5uVw/s2794/Figure-4++Rhythm+post-shock+%25284-28.21-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1125" data-original-width="2794" height="161" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh9TOWaTmOfqGuDUiKWb0eDjnKR2BK67iht_KgRu-w8z-LklZPJR6qv_tB8wHf-yeLYIEfqNUM06GqjQhC60sFveMAJv_JtuvmlIR97P3mDkecZltnrZTa88iRuhioOR0N-4j3wiWw5uVw/w400-h161/Figure-4++Rhythm+post-shock+%25284-28.21-2021%2529-USE.png" style="cursor: move;" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; text-align: justify;"> Lead II rhythm strips obtained <i><u>during</u></i> the WCT rhythm (<b><u>Panel A</u></b>) — and immediately <i><u>after</u> </i>synchronized cardioversion with 100 joules (<i>the RED arrow shows the point where cardioversion was applied</i>). <b><u>Panel B</u></b> — was obtained moments after cardioversion.</span></span></td></tr></tbody></table><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"> </span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><span style="caret-color: rgb(0, 0, 0); color: black; font-family: arial; font-size: medium; text-align: left;"></span></span></span></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(0, 0, 0); color: #0d0d0d; font-family: -webkit-standard; margin-left: auto; margin-right: auto; text-align: justify;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-4dualRB8TZNVrmgMWwAti5SUYxeuCN5dp7WqnSuiSE1T0c7EOQ_yp18zPPgyUngPoJHDHlOOJisdHNYbe4X3SfrVPQd7iCRx-Q1J-a3QHzp3D1x_He5S9nJ6VtgNgcvl8KoasXIOx-Y/s2523/Figure-5++ECG-3+repeat+%25284-23.21-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1246" data-original-width="2523" height="198" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi-4dualRB8TZNVrmgMWwAti5SUYxeuCN5dp7WqnSuiSE1T0c7EOQ_yp18zPPgyUngPoJHDHlOOJisdHNYbe4X3SfrVPQd7iCRx-Q1J-a3QHzp3D1x_He5S9nJ6VtgNgcvl8KoasXIOx-Y/w400-h198/Figure-5++ECG-3+repeat+%25284-23.21-2021%2529-USE.png" style="cursor: move;" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505; text-align: justify;"> Following treatment with Atropine — the patient stabilized, and this 12-lead ECG was obtained.</span></span></td></tr></tbody></table><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;">=======================================<o:p></o:p></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><u><br /></u></b></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><u><i><span style="color: red;">A</span>dditional</i> <span style="color: red;">M</span>aterial on <i><span style="color: red;">T</span>oday's</i> <span style="color: red;">C</span>ASE:</u></b><o:p></o:p></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in; text-align: center;"><span lang="ES-US"><span style="font-family: arial; font-size: medium;"> </span></span></p><div class="separator" style="caret-color: rgb(0, 0, 0); clear: both; color: black; font-family: -webkit-standard; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropbox.com/s/tua438vvhicadaa/z-ECG%20Audio%20Pearl-37%20Is%20Patient%20Stable%20%284-26.21-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1502" data-original-width="2048" height="294" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgozv3YIGrR79emqJ7_D2jCl52OpZxa6sSJF9aduxgfmrcAiHlZOC5lPgs6oIJwde3tgxviMScvfhyphenhyphenKBrXsOVl799rFtCDiy12AZWV9YoePQiOrmz9iiIqVR477rFKKsX5_C3jfaSrl0vs/w400-h294/ECG+MP-37+Hemodyn.+Stable+%25284-26.21-2021%2529-USE.png" width="400" /></span> —</a><i style="text-align: justify;"><span lang="ES-US"> </span></i></span></div><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in; text-align: center;"><span style="font-family: arial; font-size: medium;"><i>Today’s</i> <b><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>37 (</b><i>6:00 minutes <b><u>Audio</u></b></i><b>)</b> — Reviews how to determine IF Your Patient with an Arrhythmia is <b><i><u>Hemodynamically</u></i> Stable</b>!<o:p></o:p></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><br /></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"></span></p><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="caret-color: rgb(0, 0, 0); color: #0d0d0d; font-family: -webkit-standard; margin-left: auto; margin-right: auto; text-align: justify;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0rS2q8YoANCHRuBzun8pchBJ-MgYoajTQln_WbFz15MamRJiJeAvcsErjnEbK9xsb6O8wwCqrH6WGzCXXjZ7scwxGk43gIf4drrwJUuja5ddXhqsqQPYttUq9COZgRj5_K8kjHXQzDE4/s2048/Figure-7+Lead+V1+Morphology+%25284-29.21-2021%2529-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1088" data-original-width="2048" height="213" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0rS2q8YoANCHRuBzun8pchBJ-MgYoajTQln_WbFz15MamRJiJeAvcsErjnEbK9xsb6O8wwCqrH6WGzCXXjZ7scwxGk43gIf4drrwJUuja5ddXhqsqQPYttUq9COZgRj5_K8kjHXQzDE4/w400-h213/Figure-7+Lead+V1+Morphology+%25284-29.21-2021%2529-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium; text-align: justify;"><b><u><span style="color: #050505;">Figure:</span></u></b><span style="color: #050505;"> Use of <b>lead V1</b> for assessing <b>QRS morphology</b> during a WCT rhythm <b>(</b><i>taken from</i><b> </b></span><b><span style="color: #050505;"><a href="https://ecg-interpretation.blogspot.com/2021/02/blog-196-ecg-mp-13-is-this-vt-or-svt.html" target="_blank">ECG Blog #196</a></span></b><b><span style="color: #050505;">)</span></b></span><span style="color: #050505; text-align: justify;"><span style="font-family: arial; font-size: medium;">.<br /></span></span></td></tr></tbody></table><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"> </span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"> </span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;">=======================<o:p></o:p></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><span style="font-family: arial; font-size: medium;"><b><i><u>Related</u></i></b><b><u> ECG Blog Posts to <i>Today’s</i> Case: </u></b></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"></p><ul style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; text-align: left;"><li style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a> </b>— Reviews my System for <b><i>Rhythm</i></b> <b>Interpretation</b>, usin</span></span><span style="font-family: arial;">g the </span><b style="font-family: arial;"><span style="color: red;">P</span>s, <span style="color: red;">Q</span>s & 3<span style="color: red;">R</span> Approach</b><span style="font-family: arial;">.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/04/blog-210-ecg-mp-27-regular-wct-how-fast.html " target="_blank">ECG Blog #210</a></b> — Reviews the <b>Every-Other-Beat (</b><i>or Every-Third-Beat</i><b>) Method</b> for estimation of <i>fast</i> heart rates — and discusses another case of a <i>regular</i> WCT rhythm.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/blog-196-ecg-mp-13-is-this-vt-or-svt.html" target="_blank">ECG Blog #196</a></b> — Reviews another Case with a <i>Regular</i> WCT Rhythm. </span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/blog-197-ecg-mp-14-svt-with-aberrancy.html" target="_blank">ECG Blog #197</a></b> — Reviews the concept of <b><i>Idiopathic</i></b> <b>VT</b>, of which <b><i><u>Fascicular</u></i></b> <b>VT</b> is one of the 2 most common types.</span><b><span style="font-family: arial; font-size: medium;"> </span></b></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-204-ecg-mp-22-bundle-branch.html" target="_blank">ECG Blog #204</a></b> — Reviews the ECG diagnosis of the <b>Bundle Branch Blocks (</b><i>RBBB/LBBB/IVCD</i><b>)</b>.</span><b><span style="font-family: arial; font-size: medium;"> </span></b></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-203-ecg-mp-2021-axis.html " target="_blank">ECG Blog #203</a> </b>— Reviews ECG diagnosis of Axis and the <b>Hemiblocks</b>. For review of QRS morphology with the <b><i>Bifascicular</i></b> <b>Blocks (</b><i>RBBB/LAHB; RBBB/LPHB</i><b>)</b> — See the video <b>ECG Media Pearl #21</b> in this blog post.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/04/ecg-blog-211-ecg-mp-28-why-does.html" target="_blank">ECG Blog #211</a> </b>— <i>WHY</i> does <b><i>Aberrant</i></b> <b>Conduction</b> occur?</span></li></ul><p style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; text-align: left;"></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"><br /></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in; text-align: center;"><span style="color: #050505;"><span style="font-family: arial; font-size: medium;"><br /></span></span></p><p class="MsoNormal" style="caret-color: rgb(0, 0, 0); color: black; font-family: -webkit-standard; margin: 0in;"></p><div class="separator" style="clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1YwNX4Pgn2HbCNcLCEN20_vF-M0zgHzIa9FFUfC5qlvgirrxgeaNQRYghKydgXM0uJLyUBJYWO8_kZvEmNq7M_H_m3OYDuJWlFQUHxiAtgJ69Dng8fcWG6wIV9CKJvZVRn52XfEkNwBU/s613/0++++-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1YwNX4Pgn2HbCNcLCEN20_vF-M0zgHzIa9FFUfC5qlvgirrxgeaNQRYghKydgXM0uJLyUBJYWO8_kZvEmNq7M_H_m3OYDuJWlFQUHxiAtgJ69Dng8fcWG6wIV9CKJvZVRn52XfEkNwBU/w400-h16/0++++-RED+LINE-+Use+in+Blogs.png" width="400" /></span></a></div><div class="separator" style="clear: both; color: #050505; font-family: -webkit-standard; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><span style="caret-color: rgb(0, 0, 0); color: black; font-family: arial; font-size: medium; text-align: left;"><div style="text-align: center;"><span style="caret-color: rgb(5, 5, 5); color: #050505;"><br /></span></div></span><span style="color: #0d0d0d; font-family: arial; font-size: medium; text-align: left;"></span></div></span></span></div><div style="text-align: justify;"><br /></div><div><br /></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-22545061919061634932023-11-04T08:40:00.001-04:002023-11-04T08:40:24.781-04:00ECG Blog #402 — Will Adenosine Convert This? <div><span style="font-family: arial; font-size: medium;"><br /></span></div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><p class="MsoNormal" style="margin: 0in;">You are told that the patient next door is in the <b><i><u>regular</u></i></b> <b>SVT (</b><i><u>S</u>upra<u>V</u>entricular <u>T</u>achycardia</i><b>) rhythm</b> shown in <u style="font-weight: bold;">Figure-1</u>.</p><p class="MsoNormal" style="margin: 0in;"><br /></p><p class="MsoNormal" style="margin: 0in;"><b><u>QUESTIONS:</u></b></p><p class="MsoNormal" style="margin: 0in;"></p><ul><li>Is the rhythm AVNRT <u>or</u> AVRT? </li><li><i>Is Adenosine likely to convert this rhythm?</i></li></ul><p></p></div></span><div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjLoFbamzeswyX53r_QkuvZX1njt199I4zFHn7JnZJBvJ27fDwaU2ORSytlYYNBuV1peA_g36TBQ_U7Gzxj1iiRQnF2QftHlzpPDYOPWlSCIU1p9dF1nn9MgA2RH_iGEVuu9VhzuBZQxvFYQMWX8fyGqez9WQjlWhVnJrQIROCdLnjNy-6YZ4gjexQFCsA/s3782/Figure-1%20%20ECG-1%20Fast%20AFib%20(88-26.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2204" data-original-width="3782" height="233" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjLoFbamzeswyX53r_QkuvZX1njt199I4zFHn7JnZJBvJ27fDwaU2ORSytlYYNBuV1peA_g36TBQ_U7Gzxj1iiRQnF2QftHlzpPDYOPWlSCIU1p9dF1nn9MgA2RH_iGEVuu9VhzuBZQxvFYQMWX8fyGqez9WQjlWhVnJrQIROCdLnjNy-6YZ4gjexQFCsA/w400-h233/Figure-1%20%20ECG-1%20Fast%20AFib%20(88-26.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-1:</u></b><span style="text-align: justify;"> <i>How would YOU interpret this ECG?</i></span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span><div style="text-align: justify;"><span style="font-family: arial;"><b><u><span style="font-size: medium;"><i>MY Thoughts</i> on the ECG in Figure-1:</span></u></b></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">When faced with a challenging cardiac arrhythmia — It is a "luxury" to have access to a long lead rhythm strip containing <b>3 <i><u>simultaneously</u>-recorded</i> leads</b>. This provides the optimal chance that QRS size and atrial activity (<i>if present</i>) will be readily detectable.</span></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="text-align: left;"><b><u>PEARL <span style="color: red;">#</span>1:</u></b> The 3 leads I favor for rhythm determination are precisely the leads that are shown in </span><u style="text-align: left;">Figure-1</u><span style="text-align: left;">. These are: </span></span></div></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><b><u>Lead II</u></b> — which is clearly the <i>BEST</i> lead in most cases for visualing P waves and/or other atrial activity. <b><i>Sinus</i></b> <b>rhythm</b> is defined by the presence of an <i>upright</i> P wave with constant PR interval in lead II.</span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><b><u>Lead V1</u></b> — which is the 2nd-best lead for visualizing P waves <b>(</b><i>although the P wave will not necessarily be upright in lead V1 with sinus rhythm</i><b>)</b>. Lead V1 offers the best perspective of <i><u>right</u>-sided</i> QRS morphology.</span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><b><u>Lead V5</u></b> — which offers an excellent perspective of <i><u>left</u>-sided </i>QRS morphology.</span></span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">And then I took a <u>c</u><i><u>loser</u> LOOK</i> — at the rhythm in <u>Figure-1</u>.</span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">==============================</span></span></div><div style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><b><u><span style="color: red;">Q</span>UESTION:</u></b></span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">Is the rhythm in </span><u style="text-align: left;">Figure-1</u><span style="text-align: left;"> <i>truly</i> regular?</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"> — <u style="font-weight: bold;">HINT:</u> Before answering — <i>LOOK</i> at <u style="font-weight: bold;">Figure-2</u>.</span></span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiYQm0mWPWhWsK0zuws9KY8gG6uI-2kBRPjxcKda0pwv1CgnETc4gfPqMUdnorqhZS3gVDn58-B3fM6k5pU-xeRQc4as1Bl4_vI18cjacgrTH1KwHjiU7L0j4xu-G3NQVp6hCxECAMBIJEfKnADhAeBtXLsUghBKC-D4xyWAHa17DHo50j4rhedvhOP6CM/s3782/Figure-2%20%20ECG-1%20Fast%20AFib%20(88-26.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2204" data-original-width="3782" height="233" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiYQm0mWPWhWsK0zuws9KY8gG6uI-2kBRPjxcKda0pwv1CgnETc4gfPqMUdnorqhZS3gVDn58-B3fM6k5pU-xeRQc4as1Bl4_vI18cjacgrTH1KwHjiU7L0j4xu-G3NQVp6hCxECAMBIJEfKnADhAeBtXLsUghBKC-D4xyWAHa17DHo50j4rhedvhOP6CM/w400-h233/Figure-2%20%20ECG-1%20Fast%20AFib%20(88-26.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-2:</u></b><span style="text-align: justify;"> Is the rhythm <i>truly</i> regular? (<i>See text</i>).</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><br /></u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>Is <i>Today's</i> Rhythm <i>Truly</i> Regular?</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Although today's rhythm looks regular — it is <u style="font-style: italic;">not</u> completely regular, as I highlight in <u>Figure-2</u>:</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Even without calipers — <i>Doesn't it appear that the R-R intervals within the RED dotted ovals are a little bit longer than the R-R intervals within the BLUE ovals? </i>This establishes that the rhythm is <i><b>irregularly</b></i> <b>irregular</b>. Otherwise:</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">The <b><i>rate</i></b> of today's rhythm is <b>fast (</b><i>close to ~150/minute</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;">The <b>QRS</b> complex is <b><i>narrow</i></b> in all 12 leads.</span></li><li><span style="font-family: arial; font-size: medium;">Although difficult to assess atrial activity given all of the baseline artifact — it appears that <b><u style="font-style: italic;">no</u> P waves</b> are seen.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">Therefore:</u> The finding of an irregularly irregular rhythm with a narrow QRS complex, and the complete absence of P waves — establishes the diagnosis as <b>A<span style="color: red;">F</span>ib (</b><i><u>A</u>trial <u>F</u>ibrillation</i><b>)</b>, here with a <b><i>rapid</i> ventricular response</b>.</span></li><li><span style="font-family: arial; font-size: medium;">Otherwise — the axis is normal — R wave progression is appropriate — there is no chamber enlargement — and some nonspecific ST depression is seen in the lateral chest leads that is probably <i>rate-related</i>.</span></li></ul><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;"><div style="text-align: justify;"><u style="font-weight: bold;"><br /></u></div>PEARL <span style="color: red;">#</span>2:</u> When the rate of <b>AFib </b>is rapid — this irregular tachycardia may look regular when it is <u>not</u>. <br /></span><ul><li><span style="font-family: arial; font-size: medium;">That the rhythm is AFib — is easier to appreciate in <u style="font-weight: bold;">Figure-3</u>.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0L4p5p3KagPRfooE_bblG6zRNG5uxzmGc1krvJGJ07hJlVaGGKRzs3OZDbiSQXFfcv5uKDw0-n74mVAq85vZedkKA063BDNdPJlAWAehRsmdmlRM2GX6bPEJF88-R1a69xNmaVVfs99RozLSQ-G54EzU-5-02KeoKyCJ6rfAgd62msFmxUPula1FJjoM/s3664/Figure-3%20%20ECG-1%20Arrows-Irreg%20(8-26.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2134" data-original-width="3664" height="233" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0L4p5p3KagPRfooE_bblG6zRNG5uxzmGc1krvJGJ07hJlVaGGKRzs3OZDbiSQXFfcv5uKDw0-n74mVAq85vZedkKA063BDNdPJlAWAehRsmdmlRM2GX6bPEJF88-R1a69xNmaVVfs99RozLSQ-G54EzU-5-02KeoKyCJ6rfAgd62msFmxUPula1FJjoM/w400-h233/Figure-3%20%20ECG-1%20Arrows-Irreg%20(8-26.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-3:</u></b><span style="text-align: justify;"> Today's rhythm is <i><u>not</u> </i>regular (<i>See text</i>).</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><b><u>Figure-3 shows <i>Today's</i> Rhythm is <i>Not</i> Regular</u></b></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">The <i>double RED </i>arrows that I've drawn near the middle of the long lead V5 rhythm strip are all the <i><u>same</u></i> length.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Although extremely subtle — the 5 double arrows in the top 2 rows of the long <b>lead V5 <i>rhythm</i> strip</b> — are each a little bit <i>shorter</i> than the 2 double arrows in the lower row.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>The <span style="color: red;">C</span>ASE <span style="color: red;">C</span>ontinues:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Today's patient was treated with IV, and then PO Metoprolol. The <b><i><u>repeat</u></i></b> <b>ECG</b> after this treatment is shown in <u style="font-weight: bold;">Figure-4</u>.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Following treatment with a ß-blocker — <b><i>the rate of today's rhythm has slowed considerably</i></b>. Although baseline artifact remains — it should be evident that <u style="font-style: italic;">no</u> P waves are present.</span></li><li><span style="font-family: arial; font-size: medium;">The irregular irregularity of today's rhythm in <u>Figure-4</u> is now obvious. Clearly, the rhythm is <b>AFib </b>— here with a <b><i>controlled</i> ventricular response</b>.</span></li><li><span style="font-family: arial; font-size: medium;">Note that the ST depression that was previously seen in the lateral chest leads of <u>Figure-3</u> — has now resolved, confirming that this ST depression was indeed <i>rate-related.</i></span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6GD1ToIEInx9oJos5dldJeaD8X3z7b2oO707uF60fBmAO5QnUIKQMIwcWnAa5v3WXxz_08dWLAidH63kZHXxtD-lrAC0CrLfAafpJLuMC1p8oqOSZBpzQjy9ktb-0FGEe5l4FulyggCBh8H7LsBXBcnYJWamvspLFJW7C6OK69r3RCOgRz7ERvYtiSU4/s3784/Figure-3%20%20ECG-2%20Irreg%20AFib%20(8-26.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1830" data-original-width="3784" height="194" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg6GD1ToIEInx9oJos5dldJeaD8X3z7b2oO707uF60fBmAO5QnUIKQMIwcWnAa5v3WXxz_08dWLAidH63kZHXxtD-lrAC0CrLfAafpJLuMC1p8oqOSZBpzQjy9ktb-0FGEe5l4FulyggCBh8H7LsBXBcnYJWamvspLFJW7C6OK69r3RCOgRz7ERvYtiSU4/w400-h194/Figure-3%20%20ECG-2%20Irreg%20AFib%20(8-26.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-4:</u></b><span style="text-align: justify;"> Repeat ECG <i><u>after</u></i> IV and PO Metoprolol.</span></span></td></tr></tbody></table></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i><br /></i></u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>Would <span style="color: red;">A</span>denosine have Worked</i> for <i>Today's</i> Rhythm?</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Adenosine was not used in today's case. Instead — rate control of this patient's AFib, as well as confirmation of this rhythm diagnosis was obtained by treatment with a ß-blocker.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">To EMPHASIZE:</u> It would be extremely easy <i><u>not</u></i> to realize that the <b><i>rapid</i></b> <b>SVT (</b><i><u>S</u>upra<u>V</u>entricular <u>T</u>achycardia</i><b>) rhythm</b> that today's patient presented with was irregular — because <b>(</b><i>as per PEARL #2</i><b>)</b><i> — </i><b>When AFib is rapid, it may <i><u>look</u></i> quite regular</b>. Clinically, this is usually not problematic — since initial emergency treatment of many SVT rhythms is similar.</span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">The above said — When possible, optimal management of SVT rhythms is much easier to achieve when you <u style="font-style: italic;">know</u> what the <i>specific</i> rhythm diagnosis is.</span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/07/ecg-blog-240-55-what-kind-of-regular-svt.html" target="_blank">ECG Blog #240</a></b> — reviews my approach to the ECG assessment of <b><i>regular</i></b> <b>SVT rhythms</b>.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><span><b><u>Adenosine</u> —</b> is a wonderful drug for emergency treatment of <i>reentry</i> SVTs. Even in cases in which Adenosine does not convert the rhythm — it will often facilitate rhythm diagnosis by its transient <i>rate-slowing</i> effect. <b>Although the drug is usually safe (</b><i>because of its ultra-short half-life</i><b>) — side effects <i><u>can</u></i> occur,</b> and these are <i>not</i> uniformly short-lived</span></span><span style="font-family: arial;">. Therefore — Adenosine is probably best <i>avoided</i> for treatment of rhythms</span><span style="font-family: arial;"> for which the drug has </span><i style="font-family: arial;">little</i><span style="font-family: arial;"> to no chance of being effective </span><b style="font-family: arial;">(</b><span style="font-family: arial;">ie, </span><i style="font-family: arial;">If you <u>know</u> that the SVT you are treating is AFib — then <b>its better to use some <u>other</u> rate-slowing or antiarrhythmic agent</b> — rather than risking side effects from a drug that is unlikely to work</i><b style="font-family: arial;">)</b><span style="font-family: arial;">.</span></span></li><li style="text-align: justify;"><span style="font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><i>See </i><u style="font-weight: bold;">Figure-5</u> and <b><u>-6</u> </b>— <i>for more on </i><b>Adenosine</b>. </span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: justify;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDWoBVW9ISujK12jmZqjkV4JhiNO5P6E3LKF4BIzUxtE9gn8TMhO0CoE_ccazCJv3rPbI1M0mpEjhVcBtGf_tWzR9Vci_4MRNCnV3_Et5f7VBsBDPaxvKwVt-vY6AhEgeDR46w9KEqo2Y/s2048/Figure-5++Adenosine+pp+1-2-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1858" data-original-width="2048" height="363" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDWoBVW9ISujK12jmZqjkV4JhiNO5P6E3LKF4BIzUxtE9gn8TMhO0CoE_ccazCJv3rPbI1M0mpEjhVcBtGf_tWzR9Vci_4MRNCnV3_Et5f7VBsBDPaxvKwVt-vY6AhEgeDR46w9KEqo2Y/w400-h363/Figure-5++Adenosine+pp+1-2-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-5:</u></b><span style="text-align: justify;"> Pages 1 and 2 on Pros & Cons of using <b>Adenosine (</b><i>excerpted from my ACLS-2013-ePub</i><b>)</b>.</span></span></td></tr></tbody></table><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"> </span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><table cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody><tr><td><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiO-S4E-pmy58maGyzrobyrPQFmR-_diPG-JGkgu9cPHsqSLwAkadrte-XLKia6BN-iAAkwRAyOjCkUdqSdw43VLS-Gbr3bBLhDsAH5VwPxeJgwpY9dF0iKKZiY-_10ReI735jLMiZxslE/s2048/Figure-6+Adenosine+pp+3-4-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1705" data-original-width="2048" height="333" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiO-S4E-pmy58maGyzrobyrPQFmR-_diPG-JGkgu9cPHsqSLwAkadrte-XLKia6BN-iAAkwRAyOjCkUdqSdw43VLS-Gbr3bBLhDsAH5VwPxeJgwpY9dF0iKKZiY-_10ReI735jLMiZxslE/w400-h333/Figure-6+Adenosine+pp+3-4-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-6:</u></b><span style="text-align: justify;"> Pages 3 and 4 on Pros & Cons of using <b>Adenosine (</b><i>excerpted from my ACLS-2013-ePub</i><b>)</b>.</span></span></td></tr></tbody></table></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div><span style="font-family: arial; font-size: medium;"><p class="MsoNormal" style="margin: 0in;"><span style="color: #333333;">==================================<o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in;"><span><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Mubarak Al-Hatemi (<i>from Qatar</i>) for the case and this tracing. </span></p><div><span style="color: #333333;">==================================</span></div></span></div><div><span style="font-family: arial; font-size: medium;"><div><span><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span></span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span></span></span></p><ul><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span style="color: red;">S</span>ystematic</i></b> <b><span style="color: red;">A</span>pproach</b> to 12-lead ECG Interpretation.</span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — Reviews the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach</b> to Rhythm Interpretation.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/07/ecg-blog-240-55-what-kind-of-regular-svt.html" target="_blank">ECG Blog #240</a></b> — Reviews the approach to a <b><i>regular</i> SVT rhythm</b>.</span></li></ul><p class="MsoNormal" style="margin: 0in; text-align: justify;"><br /></p><div><br /></div><div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><span style="font-size: medium;"><br /></span></div><div class="separator" style="clear: both; text-align: center;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><br /></p></div></div></span></div></span></div></div><div><div class="separator" style="clear: both; text-align: center;"></div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"></span><span style="font-family: arial; font-size: medium;"></span><span style="font-family: arial; font-size: medium;"></span><span style="font-family: arial; font-size: medium;"></span><span style="font-family: arial; font-size: medium;"></span><span style="font-family: arial; font-size: medium;"></span></p><div class="separator" style="clear: both; text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com2tag:blogger.com,1999:blog-3364570834099131201.post-15367450628715601902023-10-28T00:07:00.000-04:002023-10-28T00:07:24.287-04:00ECG Blog #401 — What Kind of Block? <span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;">The ECG in <b style="text-decoration: underline;">Figure-1</b> was obtained from an elderly woman — who presented to the ED (<i><u>E</u>mergency <u>D</u>epartment</i>) for <b><i>dyspnea</i></b> on exertion over <b><i>recent</i></b> <b>weeks</b>. </div><div style="text-align: justify;"><ul><li>What are <i>YOUR</i> <b><i>"Quick Thoughts" </i></b>about this case?</li></ul></div></span><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj44dhcR-hI3wETivG785L0oxI3YQjJfp8p3UOf8YxuOLeTZsWe-WQK2rUnuTB_diMFbBjhSTIoOyxjks8icqEAFWGLMXd07Zp8a8PlDyp4k5nKC-E7-KL0Yc07PYloCMddZ0cI_Nnuqitt54uHNXT4CI9vKShdKF333huFSgC_EE9DwLqw-iRsBSwDW7Y/s3780/Figure-1%20%20ECG-1%20(10-7.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1948" data-original-width="3780" height="206" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj44dhcR-hI3wETivG785L0oxI3YQjJfp8p3UOf8YxuOLeTZsWe-WQK2rUnuTB_diMFbBjhSTIoOyxjks8icqEAFWGLMXd07Zp8a8PlDyp4k5nKC-E7-KL0Yc07PYloCMddZ0cI_Nnuqitt54uHNXT4CI9vKShdKF333huFSgC_EE9DwLqw-iRsBSwDW7Y/w400-h206/Figure-1%20%20ECG-1%20(10-7.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><span><u style="font-weight: bold; text-align: left;">Figure-1:</u><span style="text-align: left;"> </span></span><span>The initial ECG in today's case. </span><b>(</b><i>To improve visualization — I've digitized the original ECG using</i><span> </span><b><a href="https://www.powerfulmedical.com/" target="_blank">PMcardio</a>)</b><span>.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>MY "<span style="color: red;">Q</span>uick <span style="color: red;">T</span>houghts"</i> on <i>Today's </i>CASE:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">The ECG in </span><u style="text-align: left;">Figure-1</u><span style="text-align: left;"> is highly concerning — so it is indeed fortunate that this elderly woman came to the ED when she did!</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><b style="text-align: left;">The rhythm in <u>Figure-1</u> is complex</b><span style="text-align: left;"> — and </span><i style="text-align: left;">defies precise interpretation</i><span style="text-align: left;"> without careful study. That said — obvious findings include: </span><b style="text-align: left;">i<span style="color: red;">)</span> </b><span style="text-align: left;"><b><i>Marked</i></b> <b>bradycardia!</b> — </span><b style="text-align: left;">ii<span style="color: red;">)</span></b><span style="text-align: left;"> <i>Tiny-but-definitely</i> present <b>P waves</b> in the long lead V1 rhythm strip — which at 1st glance look like they may (?) be regular! — <b>iii<span style="color: red;">)</span></b> Non-conduction of a number of these regular P waves — suggesting <i>at least some form</i> of <b><i>significant</i></b> <b>AV block</b>; — </span><u style="text-align: left;">and</u><span style="text-align: left;">, </span><b style="text-align: left;">iv<span style="color: red;">)</span> </b><span style="text-align: left;">At least <b>3 different QRS morphologies (</b><i>if not more</i><b>)</b> — which considering that the lead monitored is </span><b style="text-align: left;">lead V1</b><span style="text-align: left;">, may represent variations of </span><b style="text-align: left;"><i>normal</i></b><span style="text-align: left;">, </span><b style="text-align: left;">RBBB</b><span style="text-align: left;"> and </span><b style="text-align: left;">LBBB conduction! (</b><span style="text-align: left;"><i><u>R</u>ight and <u>L</u>eft <u>B</u>undle <u>B</u>ranch <u>B</u>lock conduction</i></span><b style="text-align: left;">)</b><span style="text-align: left;">.</span></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>1:</u> The goal of <u style="font-style: italic;">clinical</u> ECG interpretation of a tracing such as this one is to <b><u style="font-style: italic;">expedite</u> interpretation of "the essentials"</b> — and to leave <i>details</i> of the ECG and rhythm strip shown in <u>Figure-1</u> until later, when time is available. I therefore intentionally did <i><u>not</u></i> dive deeper than the 4 general conclusions noted above in the 1st bullet — which took me <u style="font-style: italic;">no</u><i> </i><u>more</u> than seconds to arrive at! <b><u>My</u> <i style="text-decoration: underline;">Immediate</i> <u>Impression</u></b> — was that this elderly woman with a several week history of symptoms would most likely leave the hospital with a <b>pacemaker</b>.</span></span></li></ul><span style="font-family: arial; font-size: medium;"><span style="text-align: left;"><u style="font-weight: bold;"><div style="text-align: justify;"><span style="text-align: left;"><u style="font-weight: bold;"><br /></u></span></div>PEARL <span style="color: red;">#</span>2:</u> Interpretation of the 12-lead ECG in <u>Figure-1</u> is no easy task! This is because there are <i>multiple</i> QRS morphologies — and we do <u style="font-style: italic;">not</u> yet know which are supraventricular (<i>nor with what kind of conduction propoerties</i>). That said — <i>LOOK to see if there is an <u>underlying</u> rhythm!</i></span><br /></span><ul><li><span style="font-size: medium;"><span style="text-align: left;"><span style="font-family: arial;"><b>Beats #5</b> and <b>#7</b> look to be narrow <u>and</u> are both preceded by P waves with a constant and normal PR interval. This suggests that beats #5 and #7 are probably <b>normal <i><u>sinus</u>-conducted</i> beats</b>. This means that we <i><u>can</u></i> assess ST-T wave morphology for ischemic changes in <i>simultaneously-recorded</i> </span></span><b style="font-family: arial; text-align: left;">leads V1,V2,V3</b><span style="font-family: arial; text-align: left;"> for </span><b style="font-family: arial; text-align: left;">beat #5</b><span style="font-family: arial; text-align: left;"> — and in </span><b style="font-family: arial; text-align: left;">leads V4,V5,V6</b><span style="font-family: arial; text-align: left;"> for </span><b style="font-family: arial; text-align: left;">beat #7</b><span style="font-family: arial; text-align: left;">.</span></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;">There is <b>deep, <i>symmetric</i> T wave <u>inversion</u></b> with a prolonged QTc interval in <b><i>anterior</i></b> <b>leads</b> V1,V2,V3. This suggests <i>ischemia</i> of uncertain duration.</span></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;">The ST-T wave appearance in leads V4,V5,V6 is less worrisome — with shallow T inversion in V4 — and ST segment flattening with slight depression in leads V5,V6 — but which does <u style="font-style: italic;">not</u> look acute.</span></span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><u style="font-style: italic; font-weight: bold;"><span style="color: red;">B</span>eyond-<span style="color: red;">t</span>he-<span style="color: red;">C</span>ore:</u> Advanced interpreters may already suspect that <b>beat #2</b> in the long lead V1 rhythm strip is <i>sinus-conducted </i>with <b>RBBB (</b><i>given its rSR' morphology in lead V1 — and being preceded by the same PR interval before this beat as was seen for sinus beats #5 and 7</i><b>)</b>. </span></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;">Similarly — Advanced interpreters may also suspect that <b>beat #4</b> in the long lead V1 is <i>sinus-conducted</i> with <b>LBBB (</b><i>given its all negative QRS in lead V1, and its monophasic positive morphology in lead aVL — also preceded by the same PR interval as for the other sinus-conducted beats</i><b>)</b>.</span></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;">The <i>"good news"</i> — is that ST-T wave appearance in <i>simultaneously-recorded</i> leads I,II,III for <b>beat #2</b> — and in leads aVR,aVL,aVF for <b>beat #4</b> — does <u style="font-style: italic;">not</u> look acute.</span></span></li></ul><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">I</span>MPRESSION of <i><span style="color: red;"><span style="caret-color: rgb(255, 0, 0);">T</span></span>oday’s</i> <span style="color: red;"><span style="caret-color: rgb(255, 0, 0);">T</span></span>racing:</u></b></span></div><div style="text-align: justify;"><span style="text-align: left;"><span style="font-family: arial; font-size: medium;">The main problem in today's case of this elderly woman with a several week history of dyspnea on exertion — is the <b>markedly <i>bradycardic</i> rhythm</b> with some form of <b>AV block</b>. </span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">Given this patient's older age — if nothing "fixable" is found, she most likely has </span><b style="text-align: left;">SSS (</b><i style="text-align: left;"><u>S</u>ick <u>S</u>inus <u>S</u>yndrome</i><b style="text-align: left;">)</b><span style="text-align: left;"> and will need a <b>pacemaker</b></span><span style="text-align: left;"> </span><b style="text-align: left;">(</b><i style="text-align: left;">See </i><b style="text-align: left;"><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-342-this-is-12-lead-ecg.html" target="_blank">ECG Blog #342</a></b><i style="text-align: left;"> for more on SSS</i><span style="text-align: left;"><b>)</b>.</span></span></li><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">Given the history of dyspnea on exertion over a several week period (<i>but no mention of chest pain</i>) </span><i style="text-align: left;">— </i><span style="text-align: left;"><u>and</u> — the finding of <b>deep, <i>symmetric</i> T wave inversion</b> in the <b><i>anterior</i></b> <b>leads</b> <b>(</b><i>as per Pearl #2</i>) —<i> </i></span><span style="text-align: left;">it is possible that the onset of her symptoms is the result of a <b><i>"Silent MI"</i> (</b></span><i style="text-align: left;">See </i><b style="text-align: left;"><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-228-44-what-is-main-problem.html" target="_blank">ECG Blog #228</a></b><i style="text-align: left;"> for more on "Silent" MI</i><b style="text-align: left;">)</b><span style="text-align: left;">. </span></span></li><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left;"><u style="font-weight: bold;"><i>KEY</i> Point:</u> As fascinating as today’s rhythm disorder is — a detailed explanation for the mechanism of this rhythm is <u style="font-style: italic;">not</u> needed for optimal clinical management. Instead — <i>the clinical points summarized in the above 2 bullets suffice!</i> That said — I believe appreciation of the probable mechanism for today's rhythm <i><u>is</u></i> instructive, and reinforces our interpretation. For those with an interest in learning more — <i>Follow along with me below!</i></span></span></li></ul></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;">=================================</span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i><span style="color: red;">L</span>ooking <span style="color: red;">C</span>loser</i> at <i>Today's</i> <span style="color: red;">R</span>hythm:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">Regardless of whether you recognized the advanced points I raised above under <i>"Beyond-the-Core" </i>— <b>the <i>KEY</i> is to recognize the marked bradycardia </b><u>with</u><b> <i>some form</i> of significant AV block, </b><i><u>with</u></i><b> need for referral for possible (</b><i>probable</i><b>) pacemaker implantation</b>.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><i>CREDIT</i> if you also recognized the deep, symmetric anterior T wave inversion — suggestive of possible "silent MI" several weeks earlier at the time this patient's symptoms began.</span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><i><u>Next</u> <u>Steps</u> for Determination of the Rhythm:</i></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">The easiest next step in interpretation — is to <b><i><u>label</u> </i>P waves</b> in the long lead V1 rhythm strip. It is because of the small amplitude of P wave deflections in this lead — that <b><i><u><span style="color: red;">c</span>alipers</u></i></b> so greatly facilitate (<i>and speed up</i>) detection of atrial activity.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>3:</u> I've labeled with <i>RED</i> arrows in <u style="font-weight: bold;">Figure-2</u> — the P waves in the long lead V1 rhythm strip. Some of these P waves are partially hidden within some of the T waves. <i>This is precisely where <b>calipers</b> assist:</i> — Select 2 P waves in a row that you <i>definitely </i>see. Then<b><i> "walk out" this caliper setting </i></b>throughout the entire lead V1 rhythm strip.</span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>4:</u> <i>Take another LOOK</i> at the long lead V1 rhythm strip in <u>Figure-2</u>. Now that all P waves are labeled — <i>Isn't it much easier to appreciate </i>that the PR intervals before <b>beats #1</b>,<b>2</b>; <b>4</b>; <b>5</b>; <b>6</b>; <b>7</b>; and <b>8</b> are <u style="font-style: italic;">all</u> the same! This tells us that <u style="font-style: italic;">despite</u> the different QRS morphologies — <u style="font-style: italic;">each</u> of these beats <u style="font-style: italic;">is</u> <b>sinus-conducted</b>!</span></li></ul><div><br /></div></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhz5_Leo_OTrprGFJy3BhQ8_dNXJRqhQ03KriDxFaun4Ikh5V78QWSy2sqxjPOHmQH0Oh6lLvAvsxZrzxlVeZylu_y0Pm-V-kF8JJK-hBeF2vbi_KA0YsELgq4tgEe5sWlL4ziOiIZh5HviM7AdUZUCZpp6r0Xbnjcn3tMNBi6FPzCvo_HPH-uZJIlHKLY/s3788/Figure-2%20%20ECG-1%20P%20waves%20(10-7.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1952" data-original-width="3788" height="206" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhz5_Leo_OTrprGFJy3BhQ8_dNXJRqhQ03KriDxFaun4Ikh5V78QWSy2sqxjPOHmQH0Oh6lLvAvsxZrzxlVeZylu_y0Pm-V-kF8JJK-hBeF2vbi_KA0YsELgq4tgEe5sWlL4ziOiIZh5HviM7AdUZUCZpp6r0Xbnjcn3tMNBi6FPzCvo_HPH-uZJIlHKLY/w400-h206/Figure-2%20%20ECG-1%20P%20waves%20(10-7.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold; text-align: left;">Figure-2:</u><span style="text-align: left;"> I've labeled all P waves in today's rhythm with <i>RED </i>arrows.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;"><b><u><i>WHY</i> <i><span>s</span>o <span>m</span>any</i> <span style="color: red;">Q</span>RS <span style="color: red;">M</span>orphologies?</u></b></div><div style="text-align: justify;"><span style="text-align: left;">I've already alluded to why there are multiple QRS morphologies. <i>LOOK</i> at <u style="font-weight: bold;">Figure-3</u> — in which I've added <b><i>colored</i></b> <b>labels</b> to facilitate discussion.</span></div><div style="text-align: justify;"><ul><li><i style="text-align: left;"><b>RED</b></i><span style="text-align: left;"><b> arrows</b> in </span><u style="text-align: left;">Figure-3</u><span style="text-align: left;"> highlight </span><b style="text-align: left;"><i>sinus-conducted</i></b><span style="text-align: left;"> <b>P waves</b> — because <u style="font-style: italic;">each</u> of the QRS complexes that follow these P waves <b>(</b>ie, <i>beats #1,2,4,5,6,7 and 8</i><b>)</b> is preceded by a constant and normal PR interval.</span></li><li><span style="text-align: left;"><br /></span></li><li><span style="text-align: left;"><b><i>YELLOW</i> arrow P waves</b> are <u style="font-style: italic;">not</u> conducted. It should be apparent that there is <b><i>"<u>high</u>-<u>grade</u>" </i>2nd-degree AV block </b>— because in the presence of a regular atrial rhythm, we see several instances in which <i><u>consecutive</u></i> <i>YELLOW </i>arrow P waves do not conduct <u style="font-style: italic;">despite</u> adequate opportunity to do so <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2023/10/ecg-blog-399-which-laddergram-is-correct.html" target="_blank">ECG Blog #399</a></b> — <i>for more on "high-grade" AV block</i><b>)</b>.</span></li><li><br /></li><li><span style="text-align: left;">I distinguish the remaining P wave with a <b><i>BLUE</i> arrow</b> — because this P wave has a <b><i>longer</i></b> <b>PR interval</b> than all of the <i>RED</i> arrow P waves — and is followed by a <i>non-conducted</i> (ie, <i>YELLOW arrow</i>) </span><span style="text-align: left;">P wave after beat #3. This suggests that </span><b style="text-align: left;">beats #2</b><span style="text-align: left;"> and </span><b style="text-align: left;">#3</b><span style="text-align: left;"> form a </span><b style="text-align: left;">3:2 cycle</b><span style="text-align: left;"> of </span><b style="text-align: left;">AV Wenckebach (</b><span style="text-align: left;">ie, </span><i style="text-align: left;">Mobitz I 2nd-degree AV block</i><b style="text-align: left;">)</b><span style="text-align: left;">.</span></li></ul></div></span></div><div><span style="font-size: medium;"> </span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">I have also labeled the <b><i>different</i></b> <b>QRS morphologies</b> in <u>Figure-3</u>:</span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><u style="font-family: arial; font-weight: bold; text-align: left;">PEARL <span style="color: red;">#</span>5:</u><span style="font-family: arial; text-align: left;"> The beauty of having a 12-lead ECG with a <i>simultaneously-recorded</i> long lead rhythm strip below it — is that this provides us with "4 looks" at QRS morphology for each of the 8 beats in today's rhythm.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><br /></span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><b>Beats #1</b>,<b>4</b>,<b>6</b> and <b>8</b> — all look similar in the long lead V1 rhythm strip <b>(</b>ie,<i> they all manifest a wide negative QRS complex</i><b>)</b>. The reason that I <u style="font-style: italic;">know</u> this is consistent with <b>LBBB conduction</b> — is that we see the typical <i>all-positive</i>, wide upright QRS for <b>beat #1</b> in simultaneously-recorded lead I — for <b>beat #4</b> in lead aVL — and for <b>beat #8</b> in lead V6. QRS morphology for <b>beat #6</b> is also consistent with LBBB conduction — because the QRS is predominantly negative in each of the anterior leads.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><b>Beat #2</b> is consistent with <b>RBBB conduction</b> — because it manifests an rSR' in the long lead V1 — with a wide terminal S wave in <i>simultaneously-recorded</i> lateral lead I.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">I also labeled </span><b style="font-family: arial; text-align: left;">beat #3</b><span style="font-family: arial; text-align: left;"> as consistent with RBBB conduction — because of its similarity to the QRS appearance of beat #2 in the long lead V1 rhythm strip.</span></span></li><li><span style="font-size: medium;"><b style="font-family: arial; text-align: left;">Beat #5</b><span style="font-family: arial; text-align: left;"> is not wide, but manifests a small r' deflection in the long lead V1 — so this beat most probably reflects <b><i>incomplete</i></b> <b>RBBB conduction</b>.</span></span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>6:</u> Indication for permanent pacing is justified in today's case on multiple grounds, including: <b>i<span style="color: red;">)</span> </b>This elderly patient with marked bradycardia has been symptomatic for weeks; <b>ii<span style="color: red;">)</span> </b>Her rhythm is <i>high-grade</i> 2nd-degree AV block; <u>and</u>, <b>iii<span style="color: red;">)</span></b> There is <b><i><u>alternating</u></i></b> <b>BBB (</b><i><u>B</u>undle <u>B</u>ranch <u>B</u>lock</i><b>)</b> — which of itself is indication of severe conduction system disease at risk of developing ventricular standstill. </span></span></li></ul></div><div><span style="font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzUWh_C5qsfMdiM7-iDyGGiVPhXrEJe_8nrsebGHatxwWdCe1IYYwF-smwo6IvH-Zi1Y27Ei2h-JGmrrcXvl0JAJLL49IsLLpYvBDg_VrmJ7B6wTHsKMZDEHnaZSFSUrnJJDZ7w1HP4wuzCl2FlXLurSMGxayTeCudylLNqyBhjiyQL9KendL8LH8dy_Q/s3786/Figure-3%20%20ECG-1%20P%20waves-colors%20(10-7.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="1948" data-original-width="3786" height="206" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjzUWh_C5qsfMdiM7-iDyGGiVPhXrEJe_8nrsebGHatxwWdCe1IYYwF-smwo6IvH-Zi1Y27Ei2h-JGmrrcXvl0JAJLL49IsLLpYvBDg_VrmJ7B6wTHsKMZDEHnaZSFSUrnJJDZ7w1HP4wuzCl2FlXLurSMGxayTeCudylLNqyBhjiyQL9KendL8LH8dy_Q/w400-h206/Figure-3%20%20ECG-1%20P%20waves-colors%20(10-7.21-2023)-USE.png" width="400" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><u style="font-weight: bold; text-align: left;">Figure-3:</u><span style="text-align: left;"> I've added colored labels of P waves and QRS complexes to facilitate discussion of conduction properties (<i>See text</i>).</span></span></td></tr></tbody></table><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span>=================================</span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><div><b><u><span style="font-family: arial; font-size: medium;"><i><span style="color: red;">L</span>addergram</i> <span style="color: red;">I</span>llustration<span style="color: red;">:</span></span></u></b></div><div><div><span style="font-family: arial; font-size: medium;">At this point — I needed to work out, and <i>then draw a <u>laddergram</u></i> that I could then <i>verify</i> to ensure a plausible mechanism for today's arrhythmia.</span></div><div><ul><li><span style="font-family: arial; font-size: medium;">Sequential legends over the next 4 Figures illustrate my thought process. <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b><i> for review on how to read and/or draw Laddergrams</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><b><u>To EMPHASIZE:</u></b> Today's laddergram was challenging. I fully acknowledge needing several attempts until I could finally derive a plausible mechanism involving <b><i>dual-level</i></b> <b>block</b><i> out of the </i><b>AV node</b>. That said — my hope is that even readers with limited experience with laddergrams <i><u>will</u></i> be able to follow the mechanism I propose in my final <u>Figure-7</u>.</span></li></ul>=================================</div></div></span></span></div><div><br /></div><div>Beginning the <b>Laddergram:</b></div><div><br /></div></span></div><div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEivwc5diFWVDlScqqc8RVrUFb89vBBRzFH8bULlr3f6Tpe89Xc-_XnbgpJfLSQHrdpKhrz2BzN0Lcf6AhII6y4IYk9_uLN-KgMzKPQMFd8MRGPQ33BvtU9FtWHIDRyes23yl1ElKC1PG2UTaFM3ukS1iTaXy3nK8Ch9q7RO1XeR2Mzg8rap-Pjhoc52lLk/s3746/Figure-4%20%20Ladder-1%20(10-7.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1574" data-original-width="3746" height="168" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEivwc5diFWVDlScqqc8RVrUFb89vBBRzFH8bULlr3f6Tpe89Xc-_XnbgpJfLSQHrdpKhrz2BzN0Lcf6AhII6y4IYk9_uLN-KgMzKPQMFd8MRGPQ33BvtU9FtWHIDRyes23yl1ElKC1PG2UTaFM3ukS1iTaXy3nK8Ch9q7RO1XeR2Mzg8rap-Pjhoc52lLk/w400-h168/Figure-4%20%20Ladder-1%20(10-7.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><u style="font-weight: bold; text-align: left;">Figure-4:</u><span style="text-align: left;"> </span></span><span style="font-family: arial; text-align: justify;">It is usually easiest to begin a laddergram by marking the path of </span><b style="font-family: arial; text-align: justify;"><i>sinus</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">P waves</b><span style="font-family: arial; text-align: justify;"> through the </span><b style="font-family: arial; text-align: justify;"><i>Atrial</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">Tier (</b><i style="font-family: arial; text-align: justify;">as per the RED lines drawn directly below the onset of each of the P waves — as shown here by the large GREEN arrows</i><b style="font-family: arial; text-align: justify;">)</b><span style="font-family: arial; text-align: justify;">. Note that these </span><i style="font-family: arial; text-align: justify;"><u>RED</u></i><span style="font-family: arial; text-align: justify;"> lines in the </span><i style="font-family: arial; text-align: justify;">Atrial</i><span style="font-family: arial; text-align: justify;"> Tier are nearly vertical — since conduction of sinus P waves through the atria is rapid. Note also that the </span><b style="font-family: arial; text-align: justify;">P-P interval between successive P waves (</b><i style="font-family: arial; text-align: justify;">vertical RED lines</i><b style="font-family: arial; text-align: justify;">) is similar, albeit <i><u>not</u></i> quite equal (</b><span style="font-family: arial; text-align: justify;">ie,<i>There is slight sinus arrhythmia</i></span><b style="font-family: arial; text-align: justify;">)</b><span style="font-family: arial; text-align: justify;">.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-size: medium;"><br /></span></div><div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1AwGk6TuWiXzCjVDG8zljgSDAQiOZJgMp57GSA5nT-cNYMDWnKxc8g95RBzRQ8hFtxZ0ytLNmUlqmHRnQA0g0LwInGe2KXMaGiFN8BOQRxXtm67qvhQC_JPYEx0U22SBMPyoNzjv6inSaFTlqkFN3qwGw7byKLEHWQI56Nnx-LaGd_UaZysajDMHdMqA/s3760/Figure-5%20%20Ladder-2%20(10-7.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1626" data-original-width="3760" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg1AwGk6TuWiXzCjVDG8zljgSDAQiOZJgMp57GSA5nT-cNYMDWnKxc8g95RBzRQ8hFtxZ0ytLNmUlqmHRnQA0g0LwInGe2KXMaGiFN8BOQRxXtm67qvhQC_JPYEx0U22SBMPyoNzjv6inSaFTlqkFN3qwGw7byKLEHWQI56Nnx-LaGd_UaZysajDMHdMqA/w400-h173/Figure-5%20%20Ladder-2%20(10-7.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><u style="font-weight: bold; text-align: left;">Figure-5:</u><span style="text-align: left;"> </span></span><span style="font-family: arial; text-align: justify;">The most challenging part of most laddergrams is construction of the AV Nodal Tier — so </span><i style="font-family: arial; text-align: justify;">I typically save that for last</i><span style="font-family: arial; text-align: justify;">. Therefore, after drawing in all P waves into the </span><i style="font-family: arial; text-align: justify;">Atrial</i><span style="font-family: arial; text-align: justify;"> Tier — It's easiest to next add in the <b><i>Ventricular</i></b> <b>Tier</b> the indication of all</span><span style="font-family: arial; text-align: justify;"> QRS complexes that are conducted</span><span style="font-family: arial; text-align: justify;">. Perhaps the most complex aspect of today's rhythm — is realization that <i><u>despite</u></i> the changing QRS morphologies — <b><u style="font-style: italic;">each</u> of the 8 beats in the long lead V1 rhythm strip <u style="font-style: italic;">are</u> sinus-conducted beats!</b> The large </span><i style="font-family: arial; text-align: justify;">GREEN</i><span style="font-family: arial; text-align: justify;"> arrows show that I use the </span><i style="font-family: arial; text-align: justify;">onset</i><span style="font-family: arial; text-align: justify;"> of each QRS complex as my landmark for entering beats #1-thru-8 into the <i>Ventricular</i> Tier.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-size: medium;"><br /></span></div></div></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtgMmYYeOi0Ecbvg7k2rd-8SSm3TdDUl4yeWSBHu7QGDg84H7eho7CdnvJRLR0856WA_mRijSN6-KFuyPnlwzeOTLqVaALo4pakq-onUEzu3G6cMBVbwF42mi5APSZbzSgChO63rJZdbCEqgZpiaptWz1HKERvsjXeL-48kS0M668yQIj3y8HAeu0DHXM/s3748/Figure-6%20%20Ladder-3%20(10-7.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1632" data-original-width="3748" height="174" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtgMmYYeOi0Ecbvg7k2rd-8SSm3TdDUl4yeWSBHu7QGDg84H7eho7CdnvJRLR0856WA_mRijSN6-KFuyPnlwzeOTLqVaALo4pakq-onUEzu3G6cMBVbwF42mi5APSZbzSgChO63rJZdbCEqgZpiaptWz1HKERvsjXeL-48kS0M668yQIj3y8HAeu0DHXM/w400-h174/Figure-6%20%20Ladder-3%20(10-7.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold; text-align: left;">Figure-6:</u><span style="text-align: left;"> As noted — <u style="font-style: italic;">each</u> of the 8 beats in today's rhythm <u style="font-style: italic;">are</u> sinus-conducted beats, albeit with different conduction properties! To better illustrate normal, RBBB or LBBB conduction — I've added <i>light</i> <i>BLUE</i> and <i>PINK</i> butt ends into the <b><i>Ventricular</i> Tier</b> to schematically show the conduction defects. With completion of the <i>Atrial</i> and <i>Ventricular</i> Tiers — I was ready to begin <u style="font-style: italic; font-weight: bold;">solving</u> the<b> laddergram</b> — which entailed postulating which of the P waves from the <i>Atrial</i> Tier would be able to make it through the <b><i>AV Nodal</i> Tier</b> to be conducted to the ventricles. </span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><span><span style="text-align: justify;">=================================</span></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>7:</u> Because of the complexity of today's rhythm — I went through some <i>trail-and-error </i>before arriving at the laddergram I propose below in <u style="font-weight: bold;">Figure-7</u>. Two <i>KEY</i> principles figured in my arriving at this laddergram:</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">Principle #1:</u> It is extremely unusual for a patient to alternate between Mobitz I and Mobitz II. As a result — IF there is clear evidence of 2nd-degree AV block, Mobitz Type I <i>somewhere</i> <u>on</u> the tracing you are interpreting <b>(</b><i>or somewhere in other recently-obtained telemetry monitoring rhythm strips</i><b>)</b> — then it becomes highly likely that <b><i>some form of</i></b> <b>Wenckebach conduction</b> is responsible for other <i>unknown</i> forms of AV block that you see on that patient's ECG. </span></li><li><span style="font-size: medium;"><span style="font-family: arial;">As noted earlier — the increasing PR interval from beat #2-to-beat #3, followed by the non-conducted (<i>YELLOW arrow</i>) P wave after beat #3 — is consistent with a <b>3:2 cycle </b></span><span style="font-family: arial; text-align: left;">of</span><span style="font-family: arial; text-align: left;"> </span><b style="font-family: arial; text-align: left;">AV Wenckebach (</b><span style="font-family: arial; text-align: left;">ie,</span><span style="font-family: arial; text-align: left;"> </span><i style="font-family: arial; text-align: left;">Mobitz I 2nd-degree AV block</i><b style="font-family: arial; text-align: left;">)</b><span style="font-family: arial; text-align: left;">. This makes it highly likely that the 2:1 block of beats #1,4,5,6,7 and 8 are <i><u>also</u></i> a manifestation of Wenckebach conduction.</span></span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">Principle #2:</u> Simple AV Wenckebach results in non-conduction of a <i>single</i> on-time P wave. But as per the <i>YELLOW</i> arrow P waves in <u style="font-weight: bold;">Figure-7</u> — we see <u style="font-style: italic;">consecutive</u> on-time, non-conducted P waves within several of the R-R intervals — which strongly suggests there is <b><i><u>dual</u>-level</i> block </b><i>out of the </i><b>AV node! (</b><i>See</i><b> <a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-347-why-non-conducted-p-waves.html" target="_blank">ECG Blog #347</a></b><i> for more on dual-level AV Wenckebach</i><b>)</b>.</span></li></ul></div><div><div><span style="font-family: arial; font-size: medium;"><span style="text-align: justify;">=================================</span></span></div><div><span style="font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><i><u><span style="color: red;">P</span>utting <span style="color: red;">I</span>t <span style="color: red;">A</span>ll <span style="color: red;">T</span>ogether:</u></i></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial;"><span style="font-size: medium;">As discussed in ECG Blog #347 — the <i>DOTTED</i> line in the <i>AV Nodal</i> Tier in <u>Figure-7</u> schematically illustrates the 2 levels of exit block out of the AV Node.</span></span></li><li><span style="font-family: arial;"><span style="font-size: medium;">We <u style="font-style: italic;">know</u> that beats #2 and 3 are conducted to the ventricles in a 3:2 AV Wenckebach cycle.</span></span></li><li><span style="font-family: arial;"><span style="font-size: medium;">We <u style="font-style: italic;">know</u> that beats #1,4,5,6,7 and 8 are also all conducted beats, albeit with alternating bundle branch block.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;">This leaves us with having to postulate a path of transmission for each of the non-conducted (<i>YELLOW arrow</i>) P waves — in which the 3 R-R intervals that contain <i><u>consecutive</u></i> <i>YELLOW</i> arrow P wave</span><span style="font-family: arial;">s — <i><u>must</u></i> manifest block of 1 of these P waves at <i><u>each</u></i> of the 2 levels within the AV Nodal Tier <b>(</b><i>which I schematically show in Figure-7</i><b>)</b>.</span></span></li></ul></div><div><span style="font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEij4pE0sh84SP2vV3Mv5JiZyofX1-nsslXyxR4SJwJxOWOQO0H5CaXWqEu8f7Wxl3KO2yuAIiWcXrvf7QfHwoIPCZM4xxXvnl9lheZcm5gnrwDsDKyJvzwBAKXL8B8__S-pfxqctn7bcWg09hrcGLGK-OGsUghAgJkWt7iDSWdTEVaq5Fma2D3eOV3ggAI/s3760/Figure-7%20%20Ladder-4%20(10-7.1-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1630" data-original-width="3760" height="174" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEij4pE0sh84SP2vV3Mv5JiZyofX1-nsslXyxR4SJwJxOWOQO0H5CaXWqEu8f7Wxl3KO2yuAIiWcXrvf7QfHwoIPCZM4xxXvnl9lheZcm5gnrwDsDKyJvzwBAKXL8B8__S-pfxqctn7bcWg09hrcGLGK-OGsUghAgJkWt7iDSWdTEVaq5Fma2D3eOV3ggAI/w400-h174/Figure-7%20%20Ladder-4%20(10-7.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold; text-align: left;">Figure-7:</u><span style="text-align: left;"> My proposed <i style="font-weight: bold;">laddergram</i> for today's complex rhythm.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div><span style="font-size: medium;"><span style="font-family: arial;"><span style="caret-color: rgb(51, 51, 51); color: #333333; text-align: justify;">==================================</span></span></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><b><u><span style="color: red;"><br /></span></u></b></span></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><b><u><span style="color: red;">C</span>ASE <span style="color: red;">F</span>ollow-<span style="color: red;">U</span>p:</u></b></span></span></div><div style="text-align: justify;"><span style="text-align: left;"><span style="font-family: arial; font-size: medium;">Following assessment of this patient's initial rhythm — she was admitted to a monitored floor with plans for pacemaker placement. Unfortunately, before this could be accomplished — the patient went into cardiac arrest. She was successfully resuscitated — with a post-arrest rhythm similar to that seen in <u>Figure-1</u>.</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><i><span style="text-align: left;"><b>Cardiac cath</b> did </span><u style="text-align: left;">not</u></i><span style="text-align: left;"><i> reveal significant coronary disease!</i> So although I initially suspected that the deep anterior T wave inversion in the 12-lead tracing shown in </span><u style="text-align: left;">Figure-1</u><span style="text-align: left;"> <b>(</b><i>in association with the several week history of dyspnea</i><b>)</b> might reflect the occurence of a <b><i>"silent"</i></b> <b>infarction</b> at the time this patient's symptoms began — the negative cath argues against this. Instead — the negative cath favors more of a pure history of <b>SSS (</b><i><u>S</u>ick <u>S</u>inus <u>S</u>yndrome</i><b>)</b> in this elderly woman <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-342-this-is-12-lead-ecg.html" target="_blank">ECG Blog #342</a></b><i> for more on SSS — and </i><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-228-44-what-is-main-problem.html" target="_blank">ECG Blog #228</a></b><i> for more on "Silent" MI</i><b>)</b>.</span></span></li><li><span style="text-align: left;"><span style="font-family: arial; font-size: medium;"><br /></span></span></li><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">A </span><b style="text-align: left;"><i>permanent</i></b><span style="text-align: left;"> </span><b style="text-align: left;"><u>pacemaker</u></b><span style="text-align: left;"> was placed.</span></span></li></ul><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></div>As always — <b>I <i>welcome</i> questions</b> <i>and/or</i> <b>comments</b> on today's ECG Blog post! <i>THANK YOU for your interest! </i></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-size: medium;"><br /></span></div></div></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><div><div><span style="font-family: arial;"><div><span style="color: #333333; font-family: arial;">==================================</span></div><div><span style="font-family: arial;"><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Hans Helseth (<i>from Minnesota, USA</i>) for the case and this tracing (<i>and CREDIT to Hans for his well-drawn laddergram that I have slightly modified</i>).</span></div><div><span style="color: #333333; font-family: arial; text-align: left;">==================================</span></div><div><span style="color: #333333; font-family: arial; text-align: left;"><br /></span></div></span></div><div><span style="text-align: left;"><span><div style="text-align: justify;"><div><span><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></div><div><p class="MsoNormal"></p><ul><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span style="color: red;">S</span>ystematic</i></b> <b><span style="color: red;">A</span>pproach</b> to 12-lead ECG Interpretation.</span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — Reviews the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach</b> to Rhythm Interpretation.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> draw <b><span style="color: red;">L</span>addegrams </b></span><span><b>(</b><i>w</i></span><i>ith LINKS to more than 90 laddergram cases — many with step-by-step sequential illustration</i><b>)</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" target="_blank">ECG Blog #192</a></b> — The <b>3 <i><u>Causes</u></i></b> of <b>AV Dissociation</b>.</li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-191-ecg-mp-8-is-av-block.html" target="_blank">ECG Blog #191</a></b> — Reviews the difference between <b>AV Dissociation</b> <u>vs</u> <b><i>Complete</i> AV Block</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2023/08/ecg-blog-389-quote-from-sherlock-holmes.html" target="_blank">ECG Blog #389</a></b> — <b><a href="https://ecg-interpretation.blogspot.com/2023/04/ecg-blog-373-86yo-and-this-rhythm.html" target="_blank">ECG Blog #373</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-344-mobitz-i-mobitz-ii-or.html" target="_blank">ECG Blog #344</a></b> — for review of some cases that illustrate <b><i>"AV block problem-solving"</i></b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-259-71-what-is-dual-level-block.html" target="_blank">ECG Blog #259</a></b> — Reviews the concept of <b><i><span style="color: red;">D</span>ual-<span style="color: red;">L</span>evel </i><span style="color: red;">A</span>V <span style="color: red;">B</span>lock</b>.</span></li><li style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;">The </span><b><a href="https://hqmeded-ecg.blogspot.com/2021/10/acute-pulmonary-edema-pea-arrest-lbbb.html" target="_blank">October 25, 2021</a> post</b><span style="font-family: arial;"> in Dr. Smith's ECG Blog — My Comment (</span><i>at the bottom of the page</i><span style="font-family: arial;">) reviews my approach to another case of a </span><b><i>Dual-Level</i> Wenckebach block</b><span style="font-family: arial;">.</span><b><span style="font-family: arial;"> </span></b></span></li><li style="text-align: justify;"><span style="font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-226-42-variable-form-of.html" target="_blank">ECG Blog #226</a></b><span style="font-family: arial;"> — Works through a complex </span><b>Case Study (</b><i>including an 11:00 minute</i><span style="font-family: arial;"> </span><b>ECG</b><span style="font-family: arial;"> </span><b><i><u>Video</u></i></b><span style="font-family: arial;"> </span><b>Pearl</b><span style="font-family: arial;"> </span><i>that walks you through</i><span style="font-family: arial;"> </span><b><i>step-by-step</i></b><span style="font-family: arial;"> </span><i>in the construction of a</i><span style="font-family: arial;"> </span><b><u>laddergram</u></b><span style="font-family: arial;"> </span><i>with Wenckebach conduction and <u>dual</u>-level block within the AV node</i><b>)</b><span style="font-family: arial;">.</span></span></li><li style="text-align: justify;"><span style="font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/07/ecg-blog-243-47-why-group-beating-av.html" target="_blank">ECG Blog #243</a></b><span style="font-family: arial;"> — Reviews a case of <b>AFlutter</b> with </span><b><i>Dual-Level</i></b><span style="font-family: arial;"> </span><b>Wenckebach</b><span style="font-family: arial;"> out of the </span><b>AV Node</b><span style="font-family: arial;">.</span></span></li></ul></div></div></span></span></div></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: center;"><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"></div><span style="font-family: arial;"> <br /><div style="text-align: justify;"><b><u><span face="Arial, sans-serif" style="color: red;">A</span></u></b><span face="Arial, sans-serif"><b style="text-decoration: underline;">DDENDUM</b><b> </b><b style="text-decoration: underline;"><span style="color: red;">(</span></b><i>10/28/2023</i><b><span style="color: red;">)</span>:</b></span></div><div style="text-align: justify;"><span face="Arial, sans-serif"><b><br /></b></span></div></span></div><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; text-align: left;"></span></p><div><div style="text-align: center;"><span style="font-family: arial;"><br /></span></div><div style="text-align: center;"><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM6IE0axC-_2vJMD4d9lTnIIy2zqJZkybwADlcZyqs9SldX9AUMWa62snq9l2lgm14vb-Gtc47amXBkyV69cZd9C7oNg2BCBeRl64i1sHZm2e3DCYB5fs4bv04vDojyI5H7FabD9EOiu0/s2222/ECG-MP-52+-+2nd+Degree+AV+Blocks+%25286-24.1-2021%2529.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="462" data-original-width="2222" height="84" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM6IE0axC-_2vJMD4d9lTnIIy2zqJZkybwADlcZyqs9SldX9AUMWa62snq9l2lgm14vb-Gtc47amXBkyV69cZd9C7oNg2BCBeRl64i1sHZm2e3DCYB5fs4bv04vDojyI5H7FabD9EOiu0/w400-h84/ECG-MP-52+-+2nd+Degree+AV+Blocks+%25286-24.1-2021%2529.png" width="400" /></a></div></div><div style="text-align: center;"><span style="font-family: arial;"><br /></span></div><div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dzS5FkyrvKlqEq5iEcb4SCkWlaleXQasAuqmUx7FbIhTH7yGOTchC6pJcx7FyEHPthCXZzNgcqtZdMYcl-9Xg' class='b-hbp-video b-uploaded' frameborder='0'></iframe></span></div><span style="font-family: arial;"><div style="text-align: justify;"><span>This <b>15</b>-minute <b>ECG Video (<span style="color: red;">M</span>edia <span style="color: red;">P</span>EARL <span style="color: red;">#</span>52)</b> — Reviews the <b>3 Types</b> of <b>2nd-Degree AV Block</b> — <u>plus</u> — the <i>hard-to-define</i> term of <b><i>"high-grade"</i></b> <b>AV block</b>. I supplement this material with the following 2 PDF handouts.</span></div><div style="text-align: justify;"><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://www.dropbox.com/s/v01yvlqafd5c6z2/AV%20Blocks-Pg%2060-66%20ECG-PB%20%281-16.22-2021%29-USE.pdf?dl=0" target="_blank">Section 2F</a> (</b><i>6 pages = the <b>"<u>short</u>" Answer</b></i><b>)</b> from my ECG-2014 Pocket Brain book provides quick written review of the <b>AV Blocks</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial;"><span><b><a href="https://www.dropbox.com/s/k1jk1y4o4uu48ab/20.0-%20ACLS-2013-e-PUB-AV%20Block-Dissociaton-%2810-15.11-2014%29-LOCK.pdf?dl=0" target="_blank">Section 20</a></b> </span><b>(</b><i>54</i><i> pages = the <b>"<u>long</u>" Answer</b></i><b>)</b> from my ACLS-2013-Arrhythmias <i>Expanded</i> Version provides <i>detailed</i> discussion of <i>WHAT</i> th</span>e <b>AV Blocks</b> are — and what they are <u>not</u>!</li></ul><div><div style="text-align: left;"><span style="font-family: arial;"><ul><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://dl.dropbox.com/s/p5o4fsrvt6mzqv3/z-ECG%20Audio%20Pearl-4%20%282-12.1-2021%29-USE-Faster.m4a?dl=0" target="_blank">ECG Media Pearl #4</a></b><span> <b>(</b><i>4:30 minutes <u><b>Audio</b></u></i><b>) </b>— The <b><span style="color: red;">A</span>V <span style="color: red;">B</span>locks</b> & <i>When to Suspect <b>Mobitz I </b></i></span></span><b> </b>— <i>See</i> <b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-186-audio-pearl-4-av-blocks.html" target="_blank">ECG Blog #186</a></b> —</li></ul></span></div></div></div></span></div></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial;"><p></p></span></div></div></div></div></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://dl.dropbox.com/s/zin2ybkqkudn2ck/z-ECG-Audio%20Pearl-71%20Dual-Level%20Wenckebach%20%2810-31.1-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1456" data-original-width="2048" height="285" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiIeNsyLy4ronKJHYOwiYzX9XbB6wZmYqj8qGWpOq4txbqwmvzRNvYXVGuHe8KSyMIiRox1aI6megxL6ZyLuIukrYBFVqCEs73fX3ab1Y_ZWm6P7_yt9VFr7kRWJGkJYwhXYlxO8iFEio/w400-h285/ECG-MP-71+Dual-Level+Wenckebach+%252810-31.1-2021%2529-USE.png" width="400" /></span> —</a></span></div><div><span style="font-size: medium;"><b><span style="color: red;">E</span>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>71 (</b><i>5:45 minutes</i> <b><i><u>Audio</u></i>)</b> — Reviews the phenomenon of <b><i><span style="color: red;">D</span>ual-<span style="color: red;">L</span>evel </i></b><b><span style="color: red;">W</span>enckebach </b><i><u>out</u> of</i> the <b>AV Node (</b><i>HOW to recognize this phenomenon — and how to distinguish it from Mobitz II</i><b>)</b>.</span></div></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div></div></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><b style="font-family: arial;"><span face="Arial, sans-serif" style="font-size: medium;"><o:p> </o:p></span></b></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="font-family: arial;"><p style="margin: 0in;"><br /></p><p style="margin: 0in;"><span face="Arial, sans-serif"><br /></span></p><p style="font-family: "Times New Roman", serif; font-size: medium; margin: 0in;"><span face="Arial, sans-serif"><br /></span></p></span></span></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-19135243724831533552023-10-21T13:00:00.003-04:002023-10-22T16:55:43.664-04:00ECG Blog #400 — Is this a NSTEMI? <span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;">The ECG in <b><u>Figure-1</u></b> is from an older man with <i>known</i> coronary disease — who presents to the ED (<i><u>E</u>mergency <u>D</u>epartment</i>) with <b><i>new</i></b> <b>CP (</b><i><u>C</u>hest <u>P</u>ain</i><b>)</b> over the past several days. <i><b>Troponin is pending</b></i>.</div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>QUESTIONS:</u></b></div><div style="text-align: justify;"><ul><li>In view of this history — <i>How would you interpret</i> the ECG in <u>Figure-1</u>?</li><li><i>Should the cath lab be activated?</i></li></ul></div></span><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWxhQBZy1dm6BZ58jzCDbzwY89P9Hp2kL2_CXlqumNraor2eAEF-I-sWyoZ9U4cLD7v2ESSGIwoNWnprU38YB6xDTmylqsrO07rVNpb8EvQsM-r2Sdz1znYnUspuATPPq-6BqFtmyV6GvzBfVtD0TN-1xeP4JGjA0UiaF1fOmaFJCuvlt6Yi_UWTbpqtc/s3790/Figure-1%20ECG-1%20(10-6.42-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1842" data-original-width="3790" height="194" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhWxhQBZy1dm6BZ58jzCDbzwY89P9Hp2kL2_CXlqumNraor2eAEF-I-sWyoZ9U4cLD7v2ESSGIwoNWnprU38YB6xDTmylqsrO07rVNpb8EvQsM-r2Sdz1znYnUspuATPPq-6BqFtmyV6GvzBfVtD0TN-1xeP4JGjA0UiaF1fOmaFJCuvlt6Yi_UWTbpqtc/w400-h194/Figure-1%20ECG-1%20(10-6.42-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-1:</u></b><span style="text-align: justify;"> The <b><u style="font-style: italic;">initial</u> ECG</b> in today's case.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>MY Thoughts</i> on the ECG in Figure-1:</u></b></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">Unfortunately — there is significant </span><b style="font-family: arial; text-align: left;"><i>baseline</i></b><span style="font-family: arial; text-align: left;"> </span><b style="font-family: arial; text-align: left;">artifact</b><span style="font-family: arial; text-align: left;"> in today’s </span><span style="font-family: arial; text-align: left; text-decoration: underline;"><b><i>initial</i></b></span><span style="font-family: arial; text-align: left;"> </span><b style="font-family: arial; text-align: left;">ECG (</b><i style="font-family: arial; text-align: left;">especially in the limb leads</i><b style="font-family: arial; text-align: left;">)</b><span style="font-family: arial; text-align: left;">. That said — this artifact does </span><span style="font-family: arial; text-align: left; text-decoration: underline;"><i>not</i></span><span style="font-family: arial; text-align: left;"> prevent accurate assessment because despite the thick, limb lead baseline undulations — </span><b style="font-family: arial; text-align: left;"><i>overall QRST wave morphology remains consistent</i></b><span style="font-family: arial; text-align: left;"> throughout the tracing.</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">The rhythm is <b><i>sinus</i></b> at <b>~75/minute</b>. Intervals <b>(</b><i>PR, QRS, QTc</i><b>)</b> and the frontal plane axis are normal (<i>about 0 degrees, given the isoelectric QRS in lead aVF</i>). There is no chamber enlargement.</span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><br /></span></span></li><li><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><i>Regarding</i> <b><u>Q</u>-<u>R</u>-<u>S</u>-<u>T</u> Wave Changes:</b> There are no <b>Q</b> waves — and <b>R</b> wave progression is normal <b>(</b><i>with appropriate R wave amplitude in the anterior leads — and appropriate transition, in that the R wave becomes taller than the S wave is deep by lead V4</i><b>)</b>.</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;">
<p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-style: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px; min-height: 15px;"><br /></p><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px; min-height: 15px;"><b><i>Assessment of</i> <u>S</u>T-<u>T</u> Waves in <u>Figure-1</u>:</b></p><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px; min-height: 15px; text-align: justify;"><span style="font-style: normal;">In a patient with </span><i>new</i> CP — <i>this is an extremely <u>worrisome</u> ECG!</i></p><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px; min-height: 15px; text-align: justify;"></p><ul><li style="font-variant-caps: normal; text-align: justify;"><span style="text-align: left;">There is J-point </span><b style="text-align: left;">ST depression</b><span style="text-align: left;"> — with sharply angled <b><i>downsloping</i></b> <b>ST segments</b> in <b><i>multiple</i></b> <b>leads</b>. These depressed ST segments end with <b><i>terminal</i></b> <b>T wave positivity</b> in leads II,aVF; and in leads V2-thru-V6.</span></li><li style="font-variant-caps: normal; text-align: justify;"><span style="text-align: left;"><br /></span></li><li style="font-variant-caps: normal; text-align: justify;"><span style="text-align: left;">There is </span><b style="text-align: left;">ST elevation</b><span style="text-align: left;"> in </span><b style="text-align: left;">lead aVR > V1 (</b><i style="text-align: left;">dotted RED lines in leads in </i><b style="text-align: left;"><u>Figure-2</u>)</b><span style="text-align: left;">. The ST segment is flat in lead III.</span></li><li style="font-variant-caps: normal; text-align: justify;"><u style="font-weight: bold; text-align: left;"><br /></u></li><li style="font-variant-caps: normal; text-align: justify;"><u style="font-weight: bold; text-align: left;">IMPRESSION:</u><span style="text-align: left;"> Even without the benefit of a prior ECG for comparison in this patient with <i>known</i> coronary disease — the above noted ST-T wave changes in </span><u style="text-align: left;">Figure-2</u><span style="text-align: left;"> <i>look</i> acute. In this patient with <i><u>new</u></i> CP — <b><i>the cath lab should be activated!</i></b></span></li></ul><p></p><p></p>
<p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-style: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px; min-height: 15px;"><br /></p>
<div style="text-align: justify;"><u style="font-style: normal; font-weight: bold;">PEARL <span style="color: red;">#</span>1:</u> Although seeing an elevated Troponin would provide additional support for immediate cardiac catheterization — the clinical reality is that <b>the <i>initial</i> Troponin reading will <i><u>not</u></i> always be elevated in patients with acute coronary occlusion (</b><i>See</i> <b style="font-style: normal;"><a href="http://hqmeded-ecg.blogspot.com/2023/03/85-year-old-with-chest-pain-stemi.html" target="_blank">March 24, 2023</a> post</b> <i>in Dr. Smith's ECG Blog</i><b style="font-style: normal;">)</b>.</div><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px; text-align: justify;"></p><ul><li style="text-align: justify;"><span style="text-align: left;">Since the initial Troponin will </span><u style="font-style: italic; text-align: left;">not</u><span style="text-align: left;"> always be elevated in patients with </span><b style="text-align: left;"><i>acute</i></b><span style="text-align: left;"> </span><b style="text-align: left;">OMI (</b><span style="text-align: left;"> = </span><i style="text-align: left;">acute <u>O</u>cclusion-based <u>MI</u></i><b style="text-align: left;">)</b><span style="text-align: left;"> — <b>an <i>initial</i> normal high-sensitivity Troponin should <i><u>not</u></i> be used to rule out acute OMI in patients with <i>new</i> CP </b><u>and</u><b> an <i>abnormal</i> ECG</b>. </span></li><li style="text-align: justify;"><span style="text-align: left;">Therefore — <b>waiting until Troponin </b></span><i style="text-align: left;"><u><b>becomes</b></u></i><span style="text-align: left;"><b> elevated wastes precious time</b> <b>(</b><i>and risks loss of valuable myocardium</i><b>)</b>. Given the history in today's case </span><u style="text-align: left;">and</u><span style="text-align: left;"> the ECG shown in </span><u style="text-align: left;">Figure-2</u><span style="text-align: left;"> —</span><span style="text-align: left;"> </span><i style="text-align: left;"><b>The cath lab should be <u>immediately</u> activated!</b></i></li></ul><p></p><p></p><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-style: normal; font-variant-alternates: normal; font-variant-caps: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px; text-align: justify;"><br /></p></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5Z8I8LLP4gH4c5xdcH8I6r99TQdyx5FdNH_6H3kNqJvIDjp5QP3g-mVxaQsdPZfjAPjjGNtCsvNmTeWxu_h_r_5DL5RtGzN2j4XZf72tPuC76MsscbA3WrDknwYjGLjNBnQchbrjYyLiwWr7a8JbmNJc-lU1t1wLJAFfBux2qhAAf_Vnvs-r_tT7Ux74/s2366/Figure-2%20(Blog-400)%20labeled%20(10-15.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1154" data-original-width="2366" height="195" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5Z8I8LLP4gH4c5xdcH8I6r99TQdyx5FdNH_6H3kNqJvIDjp5QP3g-mVxaQsdPZfjAPjjGNtCsvNmTeWxu_h_r_5DL5RtGzN2j4XZf72tPuC76MsscbA3WrDknwYjGLjNBnQchbrjYyLiwWr7a8JbmNJc-lU1t1wLJAFfBux2qhAAf_Vnvs-r_tT7Ux74/w400-h195/Figure-2%20(Blog-400)%20labeled%20(10-15.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-2:</u></b><span style="text-align: justify;"> I've labeled some findings from Figure-1.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; text-align: justify;"><span style="font-size: medium;">=================================</span></span></div><div><span style="font-family: arial; font-size: medium;"><div style="margin: 0in 0in 0.0001pt; text-align: justify;"><span style="font-family: arial;"><span face=""arial" , sans-serif"><div style="margin: 0in 0in 0.0001pt;"><span style="font-family: arial;"><span face=""arial" , sans-serif"><b><u><span>P</span>EARL <span style="color: red;">#</span>2:</u></b> </span><span face=""arial" , sans-serif">As noted above — <u>ECG #1</u> is remarkable for the presence of <b><i>diffuse</i> ST depression</b> <b>(</b><i>in more than 7 leads!</i><b>)</b> — with <b>ST elevation</b> in <b>lead aVR (</b><i>as well as in lead V1</i><b>)</b>. This ECG pattern suggests <b><i><span style="color: red;">D</span>iffuse <u><span style="color: red;">S</span>ubendocardial</u></i> <span style="color: red;">I</span>schemia (</b><i>DSI</i><b>)</b> — and should immediately prompt the following <i><u>differential</u></i> Diagnosis:</span></span></div><div style="margin: 0in 0in 0.0001pt;"></div><ul style="text-align: start;"><li style="text-align: justify;"><span style="font-family: arial;"><b><i><span face=""arial" , sans-serif"><span>S</span>evere</span></i></b><b><span face=""arial" , sans-serif"> <span>C</span>oronary <span>D</span>isease (</span></b><i><span face=""arial" , sans-serif">due to LMain, proximal LAD, and/or severe 2- or 3-vessel disease</span></i><b><span face=""arial" , sans-serif">)</span></b><span face=""arial" , sans-serif"> — which in the right clinical context may indicate <b>ACS (</b><i><u>A</u>cute <u>C</u>oronary <u>S</u>yndrome</i><b>)</b>.</span></span></li><li style="text-align: justify;"><span style="font-family: arial;"><span face=""arial" , sans-serif"><b><i>Subendocardial</i></b> <b>Ischemia</b> from <b><i><u>another</u></i></b> <b>Cause (</b>ie, <i>sustained tachyarrhythmia; cardiac arrest; shock or profound hypotension; GI bleeding; anemia; "sick patient"</i>, etc.<b>)</b>.</span></span></li></ul></span></span></div><div style="margin: 0in 0in 0.0001pt; text-align: justify;"><b><u><br /></u></b></div><div style="margin: 0in 0in 0.0001pt; text-align: justify;"><b><u>To EMPHASIZE:</u></b> This pattern of <b><i>diffuse</i></b> <b><i>Subendocardial</i></b> <b>Ischemia</b> does <i><u>not</u></i> suggest acute coronary occlusion <b>(</b>ie, <i>it is <u>not</u> the pattern of an acute MI</i><b>)</b>. Instead — it suggests <b><i>ischemia</i></b> due to the above differential diagnosis!</div><div style="margin: 0in 0in 0.0001pt; text-align: justify;"><ul><li>That said, in today's patient, who presents with <i>new</i> CP <u>and</u> the ECG shown in <u>Figure-2</u> — <b>severe <i>coronary</i> disease</b> with potential need for acute reperfusion should be assumed <i><u>until</u></i> proven otherwise.</li></ul></div><div style="margin: 0in 0in 0.0001pt; text-align: justify;"><br /></div><div style="margin: 0in 0in 0.0001pt; text-align: justify;">=================================</div></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span style="text-decoration: underline;"><b>PEARL <span style="color: red;">#</span>3</b></span><span>: In today's initial ECG — <i>Did YOU notice</i> the </span><span style="text-decoration: underline;"><b><i>negative</i></b></span><span> </span><b>U waves</b><span> in </span><b>leads V3 </b><span>and </span><b>V4? </b><span><b>(</b></span><i>BLUE arrows in</i><span> <u>Figure-2</u></span><span><b>)</b>. </span></span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><span style="font-family: arial;">Having looked for negative U waves in patients with chest pain over a period of decades — I'll emphasize that this is <u style="font-style: italic;">not</u> a common finding. That said, when you do see <b><u style="font-style: italic;">inverted</u> U waves (</b><i>as we do in ECG #1</i><b>)</b> — this is a significant marker of <b><i>severe</i></b> <b>ischemia</b> <b>(</b><i>Duque-Gonzálex et al — </i></span><b style="font-family: arial;"><a href="https://www.medigraphic.com/cgi-bin/new/resumenI.cgi?IDARTICULO=102771" target="_blank">Cardiovascular Metal Sci 32(4), 2021</a>)</b><span style="font-family: arial;">.</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><span style="text-align: justify;">=================================</span></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><br /></u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i><span style="color: red;">T</span>oday's</i> <span style="color: red;">C</span>ASE <span style="color: red;">C</span>ontinues:</u></b></span></div><div style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">The worrisome findings in <u>ECG #1</u> were recognized.</span></span></div><div style="text-align: justify;"><ul><li style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">The initial Troponin came back significantly elevated. However while waiting for this initial Troponin value to come back — the patient reported that his CP had greatly decreased, and was almost gone. A <b><i><u>repeat</u></i></b> <b>ECG (</b><i>shown in </i><b><u>Figure-3</u>)</b> was obtained at this time.</span></span></li><li style="text-align: justify;"><span style="font-family: arial;"><span style="font-size: medium;"><br /></span></span></li><li style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;">Based on near resolution of the patient's CP </span><u style="font-family: arial;">and</u><span style="font-family: arial;"> the improvement on the repeat ECG </span><b style="font-family: arial;">(</b><i style="font-family: arial;">as seen in</i><span style="font-family: arial;"> </span><u style="font-family: arial;">Figure-3</u><b style="font-family: arial;">) </b><span style="font-family: arial;">— the diagnosis of </span><b style="font-family: arial;">NSTEMI (</b><i style="font-family: arial;"><u>N</u>on-<u>ST</u>-<u>E</u>levation <u>MI</u></i><b style="font-family: arial;">)</b><span style="font-family: arial;"> was made. The call for immediate cath lab activation was cancelled.</span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><br /></u></b></span></div><div><span style="font-family: arial; font-size: medium;"><b><u>QUESTIONS:</u></b></span></div><div><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial;"><span style="font-size: medium;"><i>Do YOU agree</i> with the above management decisions?</span></span></li><li style="text-align: justify;"><span style="font-family: arial;"><span style="font-size: medium;"><i>Why </i>or <i>why not?</i></span></span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAXz8Vfqt4-qEFvibxX2nLLpgvBo5F7yhCGoUsDJX5rMvl_UhzgXu9FnJhpHL4N2Ms2RVvfm0mPuBn6lPdkKaYaTHlNioIl9Xwh49fV7hgvzPuRQAp5Xu9Qx1YZuOn70s5LhjA3AvX9MT_XjzHMtfFVpyPcIosvTLxBSEYS1SWRknKnglL4ZrrTUOuGak/s3102/Figure-2%20%20ECGs-1,2%20(10-6.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="2872" data-original-width="3102" height="370" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjAXz8Vfqt4-qEFvibxX2nLLpgvBo5F7yhCGoUsDJX5rMvl_UhzgXu9FnJhpHL4N2Ms2RVvfm0mPuBn6lPdkKaYaTHlNioIl9Xwh49fV7hgvzPuRQAp5Xu9Qx1YZuOn70s5LhjA3AvX9MT_XjzHMtfFVpyPcIosvTLxBSEYS1SWRknKnglL4ZrrTUOuGak/w400-h370/Figure-2%20%20ECGs-1,2%20(10-6.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: justify;"><u>Figure-3:</u></b><span style="text-align: justify;"> Comparison of the <i>repeat</i> and <i>initial</i> ECGs in today's case.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u><i>MY Thoughts</i> on Seeing the <i>Repeat</i> ECG:</u></b></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial; text-align: left;">Lead-to-lead comparison in </span><u style="font-family: arial; text-align: left;">Figure-3</u><span style="font-family: arial; text-align: left;"> of the <b><i><u>initial</u></i></b> <b>ECG</b> in today's case — with the <b><i><u>repeat</u></i></b> <b>ECG (</b><i>done after the patient's CP had almost resolved</i><b>)</b> — shows marked improvement.</span></span></div><div style="text-align: justify;"><ul><li style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;">ST-T waves in <u>ECG #2</u> are now uniformly flat — with virtually no ST elevation or depression.</span></span></li><li style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><br /></span></span></li><li style="text-align: justify;"><span style="font-family: arial; text-align: left;"><span style="font-size: medium;"><u style="font-weight: bold;">IMPRESSION:</u> The fact that the patient's CP has virtually resolved in association with the ECG "improvements" shown in <u>Figure-3</u> — does <u style="font-style: italic;">not</u> mean that this was a "NSTEMI". Instead, <b>this change in ECG appearance</b> <b>(</b><i>in this patient who presented with new CP that has now almost completely resolved</i><b>)</b> — is indication of <b><i>"<u><span style="color: red;">d</span>ynamic</u>"</i></b> <b>ST-T wave changes!</b></span></span></li></ul><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><b><u><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial; text-align: left;"><b><u><br /></u></b></span></span></div>PEARL <span style="color: red;">#</span>4:</u></b> When the </span><span style="font-family: arial;">ECG changes evolve in a way that corresponds to the coming and going of chest pain symptoms</span><span style="font-family: arial;"> — <i>this </i></span><u style="font-family: arial;"><i>is</i></u><span style="font-family: arial;"><i> important information</i>. It tells us there </span><i style="font-family: arial;"><u>is</u></i><span style="font-family: arial;"> an </span><b style="font-family: arial;">active, <i>ongoing</i> process</b><span style="font-family: arial;"> — and that prompt cath with acute reperfusion is likely to be needed </span><i style="font-family: arial;"><u>regardless</u></i><span style="font-family: arial;"> of whether or not the </span><i style="font-family: arial;">millimeter-definition</i><span style="font-family: arial;"> of a STEMI has been satisfied.</span></span></div><div><span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><ul><li>The problem is — that the "culprit" artery may spontaneously open and close <i><u>more</u> than once</i> during its process of arriving at a final result — so that even if ST elevation resolves in association with resolution of chest pain — this <b>spontaneous reopening of the vessel, may <i>just-as-easily</i> be followed by spontaneous closure again</b> — and this time, perhaps <i><u>without</u></i> spontaneous reopening.</li><li>It is this active evolution of ST-T wave changes that may occur with the coming and going of symptoms that we define as <b><i>"<u><span>d</span>ynamic</u>"</i> <span>E</span>CG <span>c</span>hanges</b>. ST segments elevate with the onset of chest pain <b>(</b><i>signaling acute coronary occlusion</i><b>)</b> — and ST segments return toward their baseline, often followed by <b><i>"reperfusion"</i></b> <b>changes</b> of T wave inversion that signal <i><u>reopening</u></i> of the "culprit" vessel. The importance of recognizing these <b><i>"dynamic"</i></b> <b>ECG changes</b> — is that this indicates an <i><u>unstable</u></i> situation at risk of evolving further to permanent coronary occlusion.</li><li><br /></li><li>Today's case differs from the above description — in that other than reciprocal leads aVR and V1 — there was <i><u>no</u></i> ST elevation on the initial ECG. This is <i><u>not</u></i> to say that there never was a period of ST elevation — but rather that no ST elevation was captured on the one ECG that was recorded during the time that the patient had CP.</li><li>That said, today's patient with known coronary disease — presented with <i>new</i> CP <u>and</u> a worrisome ECG picture of <b>diffuse <i>subendocardial</i> ischemia</b> — with <b><i>"dynamic"</i></b> <b>ST-T wave changes</b> in association with relief of CP. </li><li><br /></li><li><u style="font-weight: bold;">BOTTOM Line:</u> Because the situation described above in today's case is clearly unstable — <b><i>prompt cardiac cath was immediately indicated </i>(</b><i>and given the history — prompt cath was indicated as soon as the initial ECG was recorded</i><b>)</b>. Given this situation — the anatomy needs to be defined to determine if acute reperfusion with PCI will be needed to prevent imminent coronary occlusion. </li><li><br /></li><li>Unfortunately, when cardiac cath is only performed days later — OMI confirmation is <u style="font-style: italic;">not</u> always possible <b>(</b><i>as was the case for today's patient — such that the "final diagnosis" of NSTEMI is questionable, as is probably the case for many patients said to have had "NSTEMI" ...</i><b>)</b>. </li></ul></div></span></div><div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div><span style="font-family: arial; font-size: medium;"><p class="MsoNormal" style="margin: 0in;"><span style="color: #333333;"><span style="font-family: arial; font-size: medium;">==================================</span><o:p></o:p></span></p><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to</span> <b><span>張三毛</span></b> <span>= JJ (<i>from Taiwan</i>) for the case and this tracing. </span></span></div><div><span style="color: #333333;">==================================</span></div></span></div><div><span style="font-family: arial; font-size: medium;"><span><p class="MsoNormal" style="margin: 0in; text-align: justify;"><br /></p><div class="separator" style="clear: both; text-align: center;"><span><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial;"><br /></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial;"><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span style="font-family: arial;"></span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span style="font-family: arial;"></span></span></p><ul><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span style="color: red;">S</span>ystematic</i></b> <b><span style="color: red;">A</span>pproach</b> to 12-lead ECG Interpretation.</span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — Reviews the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach</b> to Rhythm Interpretation.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i>Systematic</i></b> <b>Approach</b> to 12-lead ECG Interpretation.</span> </span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-183-repolarization-variant.html" target="_blank">ECG Blog #183</a></b> — Reviews the concept of <b><i><span>d</span>e<span>W</span>inter</i> <span>T</span>-<span>W</span>aves (</b><i>with reproduction of the illustrative Figure from the original deWinter NEJM manuscript</i><b>)</b>.</span> </li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-222-39-are-there-dynamic-st-t.html" target="_blank">ECG Blog #222</a></b> — Reviews the concept of <b><i><u><span>D</span>ynamic</u></i> <span>S</span>T-<span>T</span> wave <span>c</span>hanges</b>, in the context of a detailed clinical case.</span> </span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-260-repolarization-change.html" target="_blank">ECG Blog #260</a></b> — Reviews another case that illustrates the concept of <b><i>"dynamic"</i></b> <b>ST-T wave changes</b>.</span></li><li style="text-align: justify;"><span><br /></span></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/04/ecg-blog-218-ecg-mp-35-what-is.html" target="_blank">ECG Blog #218</a></b> — Reviews <i>HOW</i> to define a <b><span>T</span> wave</b> as being <b><span>H</span>yperacute<span>?</span></b></span> </span></li><li style="text-align: justify;"><span><span><b><a href="https://ecg-interpretation.blogspot.com/2021/06/ecg-blog-230-46-are-there-serial-ecg.html" target="_blank">ECG Blog #230</a></b> — Reviews <i>HOW</i> to <b><span>c</span>ompare <i><span>S</span>erial</i> <span>E</span>CGs (</b>ie, <i>"Are you comparing Apples with Apples or Oranges?"</i><b>)</b>.</span> </span></li><li style="text-align: justify;"><span><br /></span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-193-ecg-mp-10-acute-omi.html" target="_blank">ECG Blog #193</a> </b>— Reviews the concept of why the term <b>“OMI” (</b> = <i><u>O</u>cclusion-based <u>MI</u></i><b>)</b> should <i><u>replace</u></i> the more familiar term STEMI — <u>and</u> — reviews the basics on how to <b><i>predict</i></b> the <b><i>"<u>culprit</u>" </i>artery</b>.</span></li><li style="text-align: justify;"><span><br /></span></li><li style="text-align: justify;"><span><b><span><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-194-ecg-mp-11-reperfusion-of.html" target="_blank">ECG Blog #194</a> </span></b><span>— Reviews how to tell IF the <b>“culprit” (</b>ie, <i>acutely occluded</i><b>)</b> artery has <i>reperfused</i> using clinical and ECG data.</span></span></li><li style="text-align: justify;"><span><span><br /></span></span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2015/07/ecg-blog-115-early-repolarization.html" target="_blank">ECG Blog #115</a></b> — Shows an example of how drastically the ECG may change in <i>as little as</i> <b>8 minutes</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;">The <b><a href="http://hqmeded-ecg.blogspot.com/2019/01/a-patient-with-chest-pain-and-dynamic.html" target="_blank">January 9, 2019</a> post</b> in Dr. Smith's ECG Blog <b>(</b><i>Please scroll down to the <u>bottom</u> of the page to see </i><b><i>My Comment</i>)</b>. This case is remarkable for the <b><i><u>dynamic</u></i> ST-T wave changes</b> that are seen. It's helpful to appreciate: <b>i<span style="color: red;">)</span> </b>That acute ischemia/infarction is <i><u>not</u></i> the only potential cause of such changes (<i>cardiac cath was normal</i>); <b>ii<span style="color: red;">)</span></b><span style="color: red;"> </span>That changes in heart rate, frontal plane axis <i>and/or</i> patient positioning can <i><u>not</u></i> always explain such changes; <u>and</u>, <b>iii<span style="color: red;">)</span></b> That entities such as repolariztion variants, LVH <i>and/or</i> acute myopericarditis may <i><u>all</u></i> contribute on occasion to produce an evolution of challenging <i>dynamic</i> ST-T wave changes on serial ECGs.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;">The <b><a href="http://hqmeded-ecg.blogspot.com/2020/08/dynamic-st-change-in-mid-50s-man-with.html" target="_blank">August 22, 2020</a> post</b> in Dr. Smith's ECG Blog — which illustrates another case of <b><i>dynamic</i></b> <b>ST-T wave changes</b> that resulted from a <b><i>repolarization</i></b> <b>variant</b>. </li><li style="text-align: justify;"><br /></li><li style="text-align: justify;">The <b><a href="https://hqmeded-ecg.blogspot.com/2018/07/an-athletic-30-something-woman-with.html" target="_blank">July 31, 2018</a> post</b> in Dr. Smith's ECG Blog <b>(</b><i>Please <b>scroll down</b> to the <b><u>bottom</u></b></i> <i>of the page to see </i><b><i>My Comment</i>)</b>. This case provides an excellent example of <b><i>dynamic</i> S</b><b>T-<span>T</span> wave <span>c</span>hanges</b> on serial tracings <b>(</b><i>that I illustrate in My Comment</i><b>)</b> in a patient with an ongoing acutely <i>evolving</i> infarction.</li></ul><p class="MsoNormal" style="margin: 0in; text-align: justify;"><br /></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial;">=======================================</span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial;"><b><u><span style="color: red;"><br /></span></u></b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial;"><b><u><span style="color: red;">A</span>DDENDUM</u> (</b>10/21/2023<b>):</b></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial;"><br /></span></p><div style="text-align: justify;"><span><div class="separator" style="clear: both; text-align: center;"><span><span><a href="https://dl.dropbox.com/s/53c2h2p37ld2y95/z-ECG%20Audio%20Pearl-39a%20Dynamic%20ST-T%20%2811-3.21-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1540" data-original-width="2048" height="301" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi46YyU9sfDJJXy3xrDieL__7t8YCL7_5jiUHOIgYuo5Lv8yyPlPlW2jka16OoA7UZlYLniBaaaBoeqPjAHhtXfP4qYybRknLHM4hAkP8mWk5NSMERKYY8jniE7l3bmrtI__Ab-NQp0A3U/w400-h301/ECG-MP-39a+Dynamic+ST+%252811-3.1-2021%2529-USE.png" width="400" /></span> —</a></span><span> </span></span></div><p class="MsoNormal"><span><span style="font-family: arial;"><b><span style="color: red;">E</span></b><b>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>39a (</b><i>4:50 minutes <b><u>Audio</u></b></i><b>)</b> — Reviews the concept of <b><i>Dynamic</i> ST-T Wave Changes (</b><i>and how this ECG finding can assist in determining if acute cardiac cath is indicated</i><b>)</b>.</span><o:p></o:p></span></p><p class="MsoNormal"><br /></p><p class="MsoNormal"><br /></p><p class="MsoNormal"><span></span></p><div class="separator" style="clear: both; text-align: center;"><span><a href="https://dl.dropbox.com/s/haqaqaeus863uy4/z-ECG-Audio%20Pearl-46a%20Serial%20Tracings%20%2811-2.1-2021%29-USE.mp3?dl=0" target="_blank">— <span style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="1501" data-original-width="2048" height="294" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjGBpnry5zObW26LMvekXQoVv69JCSGETbgzWYCXjIB63xp2QcrIDh5e6Gysy7Z25ne2yXz_cV9m-VPec8OpmicSMufbbZliUz6kLUTF4c-HTG7qJAi91TWTmlS17cdZ_lPwdbALsHMak/w400-h294/ECG-MP-46a+Serial+ECGs+%252811-2.21-2021%2529-USE.png" width="400" /></span>—</a> <i><span> </span></i></span></div><p style="text-align: start;"></p><p class="MsoNormal"><span style="font-family: arial;"><b><span style="color: red;">E</span></b><b>CG <i><span style="color: red;">M</span>edia</i> <span style="color: red;">P</span>EARL <span style="color: red;">#</span>46a (</b><i>6:35 minutes </i><b><u><i>Audio</i></u>)</b> — Reviews <i>HOW</i> to <b><span style="color: red;">c</span>ompare <i><span style="color: red;">S</span>erial</i> <span style="color: red;">E</span>CGs (</b>ie, <i>Are you comparing "Apples with Apples" — <u>or</u> — with Oranges?</i><b>)</b>.</span></p></span></div><div><br /></div><div><br /></div><div><div class="separator" style="clear: both; text-align: center;"><span><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><span><br /></span></div><div class="separator" style="clear: both; text-align: justify;"><br /></div></div><div class="separator" style="clear: both; text-align: justify;"><br /></div><div class="separator" style="clear: both; text-align: justify;"><br /></div><div class="separator" style="clear: both; text-align: justify;"> </div><div class="separator" style="clear: both; text-align: justify;"><br /></div></span></span></div></div><div><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium;"></span><span style="font-family: arial; font-size: medium;"></span><span style="font-family: arial; font-size: medium;"></span><span style="font-family: arial; font-size: medium;"></span><span style="font-family: arial; font-size: medium;"></span><span style="font-family: arial; font-size: medium;"></span></p></div></div><style class="WebKit-mso-list-quirks-style">
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</style>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-21702341033593274542023-10-14T00:00:00.000-04:002023-10-14T00:00:57.936-04:00ECG Blog #399 — Which Laddergram is Correct? <span style="font-family: arial; font-size: medium;"><div style="text-align: justify;"><br /></div><div style="text-align: justify;">The ECG in <u style="font-weight: bold;">Figure-1</u> was obtained from a woman in her 60s — who was seen in the ED (<i><u>E</u>mergency <u>D</u>epartment</i>) as part of her evaluation for trauma following a motor vehicle accident. She was hemodynamically stable — and did <i><u>not</u></i> have chest pain, lightheadedness or syncope. </div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>QUESTIONS:</u></b></div><div style="text-align: justify;"><ul><li><i>HOW would you interpret </i>the rhythm in <u>Figure-1</u>?</li><li>Is this <b><i>"<u>high</u>-grade"</i></b> <b>AV block?</b></li><li>Is a pacemaker needed?</li></ul></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6HaEkSSMeAknC2DEGj67Ur-8eb7Kj9rLG6uNn3Xi_8bpgdj7p7mPRbrdFrgF5Sr9lhGqxwWMa_DGwKTqzAQ6PAFI1CIInVlncUw0jJnO_yRUghQBkf7WY8tAQSB1nojYN5-grq2Vf5SqFlf79t56q1VzcObQtYD2VDmtSMxCNJug7GwHxG2r3J03E3sI/s3790/Figure-1%20%20ECG-1%2012-lead%20(9-9.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="2086" data-original-width="3790" height="220" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6HaEkSSMeAknC2DEGj67Ur-8eb7Kj9rLG6uNn3Xi_8bpgdj7p7mPRbrdFrgF5Sr9lhGqxwWMa_DGwKTqzAQ6PAFI1CIInVlncUw0jJnO_yRUghQBkf7WY8tAQSB1nojYN5-grq2Vf5SqFlf79t56q1VzcObQtYD2VDmtSMxCNJug7GwHxG2r3J03E3sI/w400-h220/Figure-1%20%20ECG-1%2012-lead%20(9-9.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-1:</u></b><span style="text-align: justify;"> The <i>initial </i>ECG in today's case.</span></span></td></tr></tbody></table><br /><div style="text-align: justify;"><div><b style="text-decoration: underline;"><i><br /></i></b></div><div><b style="text-decoration: underline;"><i>MY Thoughts</i> on the ECG in Figure-1:</b></div><div><div>I routinely begin assessment of <span style="text-decoration: underline;"><i>each</i></span> 12-lead ECG I encounter — with interpretation of the rhythm. To do this — I apply the <span style="text-decoration: underline;"><b>P</b></span><b>s, </b><span style="text-decoration: underline;"><b>Q</b></span><b>s, 3</b><span style="text-decoration: underline;"><b>R</b></span><b> Approach (</b><i>See</i> <b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — <i>for review of my system</i><b>)</b>.</div><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px;"></p><ul><li>The long lead rhythm strip at the bottom of the 12-lead ECG in <span style="text-decoration: underline;">Figure-1</span> — shows a <b><i>very</i></b> <b>slow</b> and irregular rhythm, albeit the 5 beats that we see appear to manifest <b><i><u>group</u></i></b> <b>beating!</b></li><li><br /></li><li>The <span style="text-decoration: underline;"><b>Q</b></span><b>RS</b> complex is <b>wide</b> — but with very typical morphology for <b>RBBB (</b><i><u>R</u>ight <u>B</u>undle <u>B</u>ranch <u>B</u>lock</i><b>) conduction (</b>ie, <i>typical triphasic rSR' pattern in lead V1 — with wide terminal S waves in lateral leads</i><b>)</b>.</li><li><b><u>P</u> waves </b><u style="font-style: italic;">are</u> present — with what appears to be some <b><i>repetitive</i></b> <b>PR intervals</b>, which suggests that there <u style="font-style: italic;">is</u> at least some conduction of P waves!</li></ul><p></p><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px;"><span style="text-decoration: underline;"><b><br /></b></span></p><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px;"><span style="text-decoration: underline;"><b><br /></b></span></p><div><span style="text-decoration: underline;"><b>PEARL <span style="color: red;">#</span>1:</b></span> After considering the 5 <i>KEY</i> Parameters — the <i>EASIEST</i> next step for determining the mechanism of a complex rhythm — is to <span style="text-decoration: underline;"><b><i>label</i></b></span><b><i> the P waves</i></b>. I do this with <i>RED</i> arrows in <span style="text-decoration: underline;"><b>Figure-2</b></span>.</div><p style="font-feature-settings: normal; font-kerning: auto; font-optical-sizing: auto; font-size-adjust: none; font-stretch: normal; font-variant-alternates: normal; font-variant-east-asian: normal; font-variant-ligatures: normal; font-variant-numeric: normal; font-variant-position: normal; font-variation-settings: normal; line-height: normal; margin: 0px;"></p><ul><li>With P waves labeled — <i>Isn't it now much easier to appreciate </i>that the atrial rhythm is <i>quite </i>regular<i> </i>(<i>with no more than a slight sinus arrhythmia</i>)?</li></ul></div></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u><span style="color: red;">Q</span>UESTIONS<span style="color: red;">:</span></u></b></div><div style="text-align: justify;"><ul><li>Are the PR intervals in front of beats #1, 3 and 5 the same?</li><li><i>How about</i> the PR intervals before beats #2 and 4?</li><li><br /></li><li><i style="font-weight: bold; text-decoration: underline;">KEY</i><u style="font-weight: bold;"> Point:</u><i><b> </b>Why </i>is the answer to these questions important for determining the mechanism of today's rhythm?</li><li><br /></li><li><u style="font-weight: bold;">HINT:</u> <i>Unless you used </i><b><u>calipers</u></b> — You are likely to get the answer to at least one of the above questions wrong!</li></ul></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhTG7bCbnypOJMuiq58l8jOt6zFcs63Wqhf5eJ2s0W5PS9iu95cY4uMGhJsQyNQZqjxQE7HbD2a_lUYtS0pLkBD6mh51vvNyBold91HmLBPCa2X0NcWzCoNC5-FQ7IbnWHixrDlmR7OR9Cflx3CT-423Bvm6TjVYZCHcaPU3nai6aYeltvXplTph-da9oc/s3770/Figure-2%20%20Lead%20V1-P%20Waves%20(9-9.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="640" data-original-width="3770" height="68" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhTG7bCbnypOJMuiq58l8jOt6zFcs63Wqhf5eJ2s0W5PS9iu95cY4uMGhJsQyNQZqjxQE7HbD2a_lUYtS0pLkBD6mh51vvNyBold91HmLBPCa2X0NcWzCoNC5-FQ7IbnWHixrDlmR7OR9Cflx3CT-423Bvm6TjVYZCHcaPU3nai6aYeltvXplTph-da9oc/w400-h68/Figure-2%20%20Lead%20V1-P%20Waves%20(9-9.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-2:</u></b><span style="text-align: justify;"> I've labeled P waves in the long lead V1 with <i>RED </i>arrows. <i>Doesn't this make it easier to see that the atrial rhythm is regular?</i></span></span></td></tr></tbody></table><br /><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>PEARL <span style="color: red;">#</span>2:</u></b> The reason it is important to determine IF there are any PR intervals that repeat — is that if there is, then it is very likely that those beats <u style="font-style: italic;">are</u> sinus-conducted.</div><div style="text-align: justify;"><ul><li>In <u style="font-weight: bold;">Figure-3</u> — I have very carefully measured the PR intervals <u>and</u> the R-R intervals of the 5 beats in today's tracing. Note that the <b>PR intervals</b> that precede <b>beats #1</b>, <b>3</b> and <b>5</b> are all normal and <b>equal</b> <b>(</b>ie, <i>= 0.17 second</i><b>)</b>. This strongly suggests that <b>these 3 beats <u style="font-style: italic;">are</u> sinus-conducted</b>, albeit with <b>RBBB</b>.</li><li><br /></li><li><u style="font-weight: bold;">NOTE:</u> Before I used calipers to measure — I thought that the PR intervals before beats #2 and 4 were also equal. However, as shown in <u>Figure-3</u> — there <i><u>is</u></i> a <i>slight-but-real </i>difference in the PR interval before <b>beat #2</b> <b>(</b><i> = 0.36 second</i><b>) </b>— compared to the PR interval before <b>beat #4</b> <b>(</b><i> = 0.34 second</i><b>)</b>.</li></ul></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>PEARL <span style="color: red;">#</span>3:</u></b> The fact that the PR intervals before beat #2 and beat #4 are <u style="font-style: italic;">not</u> the same — <b>makes it <u style="font-style: italic;">less</u> likely (</b><i>albeit not impossible</i><b>) that these 2 beats are sinus-conducted</b>.</div><div style="text-align: justify;"><ul><li><u style="font-weight: bold;">NOTE:</u> Although the PR intervals before beats #2 and #4 are not the same — <b>the R-R intervals that precede these 2 beats <i><u>are</u></i> exactly the same! ( </b>= <i>2150 msec.</i><b>)</b>. This is <i><u>unlikely</u></i> to be by chance — <u>and</u>, I believe strongly suggests that beats #2 and #4 are <b><u style="font-style: italic;">escape</u> beats</b>.</li></ul><div><br /></div><div><b><u>PEARL <span style="color: red;">#</span>4:</u></b> If beats #2 and #4 are indeed <i>"escape"</i> beats — the fact that QRS morphology of these beats is <u style="font-style: italic;">identical</u> to the QRS morphology of <i>sinus-conducted</i> beats #1,3,5 tells us that the escape site is <i><u>within</u></i> the <b>ventricular conduction system</b> <b>(</b>ie, <i>either coming from the AV Node or the Bundle of His</i><b>)</b>.</div><div><ul><li>The fact that the R-R interval preceding beats #2 and #4 is <u style="font-style: italic;">more</u> than 10 large boxes on ECG grid paper <b>(</b>ie, <i>corresponding to a rate of slightly <u>less</u> than 30/minute</i><b>)</b> — suggests that <b>the escape site is probably <u style="font-style: italic;">below</u> the AV Node</b> <b>(</b><i>since the usual junctional "escape" rate would be faster, typically between ~40-60/minute</i><b>)</b>.</li></ul></div></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5kci4dey-C28UGaGG_kAnYGBBnsiK8IuKD-aRiw-BaLqfpmwVIurVxpUlzBMaFN1hPm0vb7KEsi2-htvkgJrZiRZqcneqokA7NgwDi2u_eA16D9zJxJN-UCXcbzT5-Tas6DROsk4CvvsqYR5VqfdN6p73h1yXNBVDZN2HikboM7zf2oFSs5-cDtXsIFM/s3770/Figure-3%20%20Lead%20V1-P%20Waves,R-R%20(9-10.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="640" data-original-width="3770" height="68" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5kci4dey-C28UGaGG_kAnYGBBnsiK8IuKD-aRiw-BaLqfpmwVIurVxpUlzBMaFN1hPm0vb7KEsi2-htvkgJrZiRZqcneqokA7NgwDi2u_eA16D9zJxJN-UCXcbzT5-Tas6DROsk4CvvsqYR5VqfdN6p73h1yXNBVDZN2HikboM7zf2oFSs5-cDtXsIFM/w400-h68/Figure-3%20%20Lead%20V1-P%20Waves,R-R%20(9-10.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-3:</u></b><span style="text-align: justify;"> I have measured PR and R-R intervals for today's tracing.</span></span></td></tr></tbody></table><br /><div style="text-align: justify;"><br /></div><div style="text-align: justify;">=====================================</div><div style="text-align: justify;"><b><i><u><span style="color: red;"><br /></span></u></i></b></div><div style="text-align: justify;"><b><i><u><span style="color: red;">P</span>utting <span style="color: red;">I</span>t <span style="color: red;">A</span>ll <span style="color: red;">T</span>ogether<span style="color: red;">:</span></u></i></b></div><div style="text-align: justify;">The precise mechanism of today's arrhythmia is complex and difficult to determine. For those with a special interest in cardiac arrhythmias — <i>READ ON! — </i>as I explore the probable mechanism of today's rhythm with laddergrams below. </div><div style="text-align: justify;"><u style="font-weight: bold;"><br /></u></div><div style="text-align: justify;">For those with less interest in complex cardiac arrhythmias:</div><div style="text-align: justify;"><ul><li><b><u><i>KEY</i> Point:</u> </b><i>We have </i><u style="font-style: italic;">already</u><i> addressed</i> the key elements in today's case needed to determine appropriate clinical management. Even if we stopped here — <i>We could conclude the following:</i></li><li>There is <b><i>marked</i></b> <b><u>bradycardia</u></b> in today's rhythm <b>(</b>ie, <i>Heart rate in the low 30s</i><b>)</b>. There are also <i>twice</i> as many P waves as QRS complexes — so at the least, there is <b>2nd-degree AV block</b>. As a result — IF no "fixable" cause is found <b>(</b>ie, <i>ischemia/infarction — electrolyte disturbance — rate-slowing medication</i><b>)</b> — then because of the AV block and very slow heart rate, this patient will probably need a <b>pacemaker</b>.</li><li>Given the <b><u>History</u> </b>in today's case<b> (</b>ie, <i>trauma following a motor vehicle accident</i><b>)</b> — special attention should be given to physical examination to rule out the possibility of <b><i><u>cardiac</u></i></b> <b>contusion</b> as the cause of the conduction disturbance <b>(</b><i>RBBB, AV block and bradycardia are among the more common disturbances seen in those patients with cardiac contusion — as per My Comment at the bottom of the page in the </i><b><a href="https://hqmeded-ecg.blogspot.com/2022/08/a-man-in-his-40s-with-multitrauma-from.html" target="_blank">August 6, 2022</a> post</b><i> in Dr. Smith's ECG Blog</i><b>)</b>.</li><li><br /></li><li>However — IF there are no signs of chest trauma from this patient's motor vehicle accident — then the <i>nonspecific</i> ST segment flattening seen in multiple leads, with slight ST elevation in leads aVR and V1 — may represent <b>diffuse <i>subendocardial</i> ischemia</b> from longstanding underlying <b><i>coronary</i></b> <b>disease</b> as a potential cause of this patient's conduction defects.</li><li><u>Finally</u> — If today's patient does not have significant underlying coronary disease — then her bradycardia with AV block may be the result of <b>SSS (</b><i><u>S</u>ick <u>S</u>inus <u>S</u>yndrome</i><b>). </b></li><li>Clinical correlation to sort this all out will clearly be needed.</li></ul></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;">=====================================</div><div style="text-align: justify;"><u style="font-weight: bold;"><br /></u></div><div style="text-align: justify;"><u style="font-weight: bold;">A <i><span style="color: red;">C</span>loser <span style="color: red;">L</span>OOK</i> at <i>Today's</i><span style="color: red;"> R</span>hythm:</u></div><div style="text-align: justify;">Further explanation of today's rhythm is probably best accomplished by means of a <b><u><span style="color: red;">L</span>addergram</u></b>.</div><div style="text-align: justify;"><ul><li>I strongly favor the laddergram illustration in <u style="font-weight: bold;">Figure-4</u> — as the most logical explanation for today's rhythm.</li><li>That said, complex arrhythmias <u style="font-style: italic;">often</u> stimulate discussion and consideration of <i><u>more</u></i> than a single mechanism — which is why I ofter an <u style="font-style: italic;">alternative</u> (<i>albeit less likely</i>) mechanism for today's rhythm in <u style="font-weight: bold;">Figure-5</u>.</li></ul></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNqXILXt_7UN1Kt2QzLHeRfQXBbm_TdFF6kfPb4_-A35E6RzhxGC-r8H6MuDj-v5vV6kvb4L5k-MYGuqPlQc9Bxa-ocjgkQWlUWVRUNaeY-xut3BbJ1PelwZviJGhPutsSM-dfnrUZ7Iem6CP-E7H6r1TdP8XpNQBBsw-g8TxXexLGl0CBYCQnzGqQTHM/s3776/Figure-4%20Ladder-1-Junctional%20Escape%20(9-10.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1646" data-original-width="3776" height="174" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhNqXILXt_7UN1Kt2QzLHeRfQXBbm_TdFF6kfPb4_-A35E6RzhxGC-r8H6MuDj-v5vV6kvb4L5k-MYGuqPlQc9Bxa-ocjgkQWlUWVRUNaeY-xut3BbJ1PelwZviJGhPutsSM-dfnrUZ7Iem6CP-E7H6r1TdP8XpNQBBsw-g8TxXexLGl0CBYCQnzGqQTHM/w400-h174/Figure-4%20Ladder-1-Junctional%20Escape%20(9-10.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-4:</u></b><span style="text-align: justify;"> This is the laddergram I favor for illustrating the mechanism of today's rhythm.</span></span></td></tr></tbody></table><div style="text-align: justify;"><br /></div><div style="text-align: justify;"></div><div style="text-align: justify;"><b style="text-decoration: underline;"><br /></b></div><div style="text-align: justify;"><b style="text-decoration: underline;">Explanation of the Laddergram in Figure-4:</b></div><div style="text-align: justify;">For those in search of a review on reading <i>and/or</i> drawing Laddergrams — Please check out my <b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b>. Regarding today's case — my explanation for the laddergram in <u>Figure-4</u> is as follows:</div><div style="text-align: justify;"><ul><li><span style="text-decoration: underline;"><b><i>What We KNOW:</i></b></span> Beats #1, 3 and 5 are <span style="text-decoration: underline;"><b><i>sinus</i></b></span><b><i>-conducted</i></b> because (<i>as stated above</i>) — the PR interval before each of these beats is <b><i>identical</i></b> <span style="text-decoration: underline;">and</span> of a <b><i>reasonable</i></b> <b>duration</b> for normal conduction <b>(</b> = <i>0.17 second — for the PR interval between each of the RED arrows and its neighboring QRS</i><b>)</b>.</li><li><b><u><br /></u></b></li><li><span style="text-decoration: underline;"><b>NOTE:</b></span> The colored <i>ARROWS</i> in <span style="text-decoration: underline;">Figure-4</span> represent <span style="text-decoration: underline;"><b><i>sinus</i></b></span><b> P waves</b>. There is slight irregularity in the occurrence of these P waves <b>(</b><i>which can be seen from the slight irregularity in the vertical lines representing spread of the impulse through the Atrial Tier</i><b>)</b>. This is consistent with a slight <b>sinus </b><span style="text-decoration: underline;"><b>arrhythmia</b></span>. </li><li><b><u><br /></u></b></li><li><span style="text-decoration: underline;"><b>PEARL </b></span><span style="text-decoration: underline;"><b><span style="color: red;">#</span><span style="color: #2e2d33;">5</span></b></span><span style="text-decoration: underline;"><b>:</b></span><b> </b>It could be <i>EASY </i>to overlook the fact that the P wave rhythm is <span style="text-decoration: underline;"><i>not</i></span> regular — <i>IF one did not use</i> <span style="text-decoration: underline;"><b>calipers</b></span>. That there is <b><i>slight</i> sinus arrhythmia </b><span style="text-decoration: underline;"><b><i>is</i></b></span><b> clinically relevant</b> to the mechanism of today’s rhythm — because it accounts for the variation in R-R intervals that we see between sinus-conducted beats #2-3 ( = 1760 msec.) — and between beats #4-5 ( = 1700 msec.). It <span style="text-decoration: underline;"><i>also</i></span> accounts for the <b>difference in PR intervals <i>before</i> beats #2 and </b><span style="color: #2e2d33;"><b>#4</b></span> — which I believe is the <b><i>KEY</i> Clue </b>to the likely etiology of today’s arrhythmia! <b>(</b>ie, <i>0.36 ≠ 0.34 second! — as per PEARL #3</i><b>)</b>.</li><li><b><u><br /></u></b></li><li><span style="text-decoration: underline;"><b>PEARL <span style="color: red;">#</span>6:</b></span> My “strategy” for the sequence in which I draw a laddergram — is to <b><i>first draw those elements</i> of the rhythm that are </b><span style="text-decoration: underline;"><b><i>most</i></b></span><b> likely to be true.</b> In <span style="text-decoration: underline;">Figure-4</span> — I thought it virtually certain that <span style="text-decoration: underline;"><i>none</i></span> of the <i>YELLOW</i> arrow P waves are conducted to the ventricles <b>(</b><i>which is why I drew the butt-ends in the AV Nodal Tier representing non-conduction to the ventricles of these impulses</i><b>)</b>.</li><li><span style="text-decoration: underline;"><b>PEARL <span style="color: red;">#</span>7:</b></span> Note that we have just established that <span style="text-decoration: underline;"><b><i>some</i></b></span><b> form</b> of <b>2nd-degree AV block</b> is present in <span style="text-decoration: underline;">Figure-4</span> — because <span style="text-decoration: underline;"><i>despite</i></span> more than adequate “opportunity” to conduct, <span style="text-decoration: underline;"><i>none</i></span> of the <i>YELLOW </i>arrow P waves are conducted to the ventricles <b>(</b><i>since </i><span style="text-decoration: underline;"><i>none</i></span><i> of these YELLOW arrow P waves occur anywhere near a QRS complex with a reasonable chance to be conducted</i><b>)</b>.</li><li><br /></li><li>This left me with <span style="text-decoration: underline;"><i>only</i></span> having to account for the final path of the <i>PINK</i> arrow P waves. As emphasized above in <i>PEARLS #3 and #4 — </i>the fact that <span style="text-decoration: underline;"><i>despite</i></span> the <i>slight-but-real </i>difference in PR intervals before <b>beats #2</b> and <b>#4</b> — the R-R intervals before beats #2 and #4 are precisely equal <b>(</b> = <i>2150 msec</i>.<b>)</b>. This strongly suggests that beats #2 and #4 are <span style="text-decoration: underline;"><b><i>escape</i></b></span> <b>beats</b> <b>(</b>ie, <i>before these PINK P waves have a chance to conduct — </i><span style="text-decoration: underline;"><i>escape</i></span><i> beats arising either from the AV Node, or more likely from the His terminate the pauses in the rhythm between beats #1-2 and between beats #3-4</i><b>)</b>.</li><li><br /></li><li><u style="font-weight: bold;">NOTE:</u> We do <u style="font-style: italic;">not</u> know IF the <i>PINK</i> arrow P waves would have conducted if escape beats #2 and #4 would not have occurred.</li><li><br /></li><li><u style="font-weight: bold;">PEARL <span style="color: red;">#</span>8:</u> In general, I reserve the term, <b><i>"<u>high</u>-grade"</i> AV block</b> for when 2 or more P waves in a row that should conduct, fail to do so. Technically, the <u>Figure-4</u> laddergram does <i><u>not</u></i> satisfy this definition — because the occurrence of escape beats #2 and #4 <i>prevent us from knowing</i> if the <i>PINK</i> P arrow waves might have conducted with a prolonged PR interval if given a chance to do so.</li><li>The above said, this semantic distinction is <u style="font-style: italic;">not</u> clinically important — since <u style="font-style: italic;">regardless</u> of whether or not the definition of <i>"high-grade"</i> AV block is satisfied — the <i>combined</i> conduction defects of marked bradycardia, with <i>at least</i> 2:1 AV block <i>plus</i> RBBB — would satisfy the need for pacing IF no "fixable" cause is found.</li></ul></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;">===================================== </div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><b><u>A 2nd Theory = <i>Dual</i> AV Nodal Pathways:</u></b></div><div style="text-align: justify;">When I first saw today's tracing — I immediately suspected that the mechanism for this arrhythmia was going to be the result of <b><i><u>dual</u></i></b> <b>AV nodal pathways</b> because: <b>i<span style="color: red;">)</span></b> There appeared to be group beating, suggestive of AV Wenckebach; <u>and</u>, <b>ii<span style="color: red;">)</span> </b>There appeared to be 2 <b><i>"families"</i></b> of <b>PR intervals </b>that repeated — <b>with a large PR interval "increment" between shorter PR intervals (</b>ie, <i>before beats #1,3,5</i><b>)</b> — <b>and the longer PR intervals</b> <b>(</b>ie, <i>before beats #2,4</i><b>)</b>.</div><div style="text-align: justify;"><ul><li>The presence of 2 functioning AV nodal pathways, each with its own PR interval and conduction capabilities — is a logical explanation for why we may sometimes see a large difference between the PR interval of 2 families of conducting beats.</li><li>I schematically illustrate this mechanism in <u style="font-weight: bold;">Figure-5</u> — in which the <i>RED</i> lines within the AV Nodal Tier represent conduction over the <i>faster</i> AV nodal pathway (<i>with the shorter PR intervals before beats #1,3,5</i>).</li><li>The <i>BLUE</i> lines within the AV Nodal Tier represent conduction over the <i>slower</i> AV nodal pathway (<i>with the longer PR intervals before beats #2 and 4</i>).</li><li><u style="font-style: italic;">Both</u> AV nodal pathways are blocked for those P waves that are not followed by any QRS complex.</li><li>The reason we see a big "jump" in the PR interval difference before beats #1 and 2 — and before beats #3 and 4 — is that the <i>faster</i> pathway is intermittently blocked, such that the P waves in front of beats #2 and 4 are conducted over the <i>slower</i> pathway (<i>with the longer PR interval</i>).</li><li><br /></li><li><u style="font-weight: bold;">The <i>Problem</i> with Figure-5:</u> As I noted above — caliper measurements show that the PR intervals before beats #2 and 4 are <u style="font-style: italic;">not</u> equal <b>(</b>ie,<i> 0.36 <u>vs</u> 0.34 second — as shown in Figure-3</i><b>)</b>. While not impossible for the slower AV nodal pathway to conduct with slightly different PR intervals — I think this is much <u style="font-style: italic;">less</u> likely than the mechanism proposed in <u>Figure-4</u>, in which beats #2 and 4 represent escape beats. </li></ul></div><div style="text-align: justify;"><br /></div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiAzke0eiiZWGEQxvsbqdALx_4eNCf1Pm4Zq5sipWknXUB1XO2EKUgOFX9eg5bltadhjhyphenhypheneT7SVjWdf6bUFVP9c1F0Lxd2TOo19x4b1Ab9KgHCWKX7jkfaxi4GCI8CaLK5u_ZsZHuDEHIcbnQ0sGI966v8IG-u76ruwtUAUKmct-H5FudCS5qBpjtaoaFE/s3796/Figure-5%20Ladder-2-Dual%20Pathways%20(9-9.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1636" data-original-width="3796" height="173" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiAzke0eiiZWGEQxvsbqdALx_4eNCf1Pm4Zq5sipWknXUB1XO2EKUgOFX9eg5bltadhjhyphenhypheneT7SVjWdf6bUFVP9c1F0Lxd2TOo19x4b1Ab9KgHCWKX7jkfaxi4GCI8CaLK5u_ZsZHuDEHIcbnQ0sGI966v8IG-u76ruwtUAUKmct-H5FudCS5qBpjtaoaFE/w400-h173/Figure-5%20Ladder-2-Dual%20Pathways%20(9-9.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="text-align: justify;"><u>Figure-5:</u></b><span style="text-align: justify;"> An alternative laddergram for today's arrhythmia — suggesting the presence of dual AV nodal pathways (<i>See text</i>).</span></span></td></tr></tbody></table><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><br /></div><div style="text-align: justify;"><div><div><div><span style="font-family: arial; font-size: medium;"><div><span style="color: #333333; font-family: arial; font-size: medium;">==================================</span></div><div><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Sam Ghali (<i>from Jacksonville, Florida — <b>@EM_RESUS</b></i>) for the case and this tracing.</span></div><div><span style="color: #333333; font-family: arial; text-align: left;">==================================</span></div><div><span style="color: #333333; font-family: arial; text-align: left;"><br /></span></div></span></div><div><span style="text-align: left;"><span><div style="text-align: justify;"><div><span><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></div><div><p class="MsoNormal"></p><ul><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span style="color: red;">S</span>ystematic</i></b> <b><span style="color: red;">A</span>pproach</b> to 12-lead ECG Interpretation.</span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — Reviews the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach</b> to Rhythm Interpretation.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> draw <b>Laddergrams </b></span><span><b>(</b><i>w</i></span><i>ith LINKS to more than 90 laddergram cases — many with step-by-step sequential illustration</i><b>)</b>.</li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-192-ecg-mp-9-av-dissociation.html" target="_blank">ECG Blog #192</a></b> — The <b>3 <i><u>Causes</u></i></b> of <b>AV Dissociation</b>.</li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/02/ecg-blog-191-ecg-mp-8-is-av-block.html" target="_blank">ECG Blog #191</a></b> — Reviews the difference between <b>AV Dissociation</b> <u>vs</u> <b><i>Complete</i> AV Block</b>.</span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2023/08/ecg-blog-389-quote-from-sherlock-holmes.html" target="_blank">ECG Blog #389</a></b> — <b><a href="https://ecg-interpretation.blogspot.com/2023/04/ecg-blog-373-86yo-and-this-rhythm.html" target="_blank">ECG Blog #373</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-344-mobitz-i-mobitz-ii-or.html" target="_blank">ECG Blog #344</a></b> — for review of some cases that illustrate <b><i>"AV block problem-solving"</i></b>.</span></li><li style="text-align: justify;"><span><br /></span></li><li style="text-align: justify;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-186-audio-pearl-4-av-blocks.html" target="_blank">ECG Blog #186</a></b><span style="font-family: arial;"> — Highlights the importance of <b><i><u>group</u></i></b> <b>beating</b> </span></span><span><span style="font-family: arial;">— and</span></span> reviews when to suspect the <b>Mobitz I </b>form of <b>2nd-Degree AV Block (</b> <i>= AV Wenckebach</i><b>)</b>.</li></ul></div><div><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-size: medium;"><span><b><a href="https://ecg-interpretation.blogspot.com/2021/09/ecg-blog-251-65-how-does-cycle-end.html" target="_blank">ECG Blog #251</a> </b><span style="font-family: arial;">—</span><b> </b><span style="font-family: arial;">Reviews the concepts of <b><i>Wenckebach</i></b> <b>periodicity</b> and the <b><i>"<u>Footprints</u>"</i> </b>o</span></span></span>f <b>Wenckebach</b> <b>(</b><i>Please check out the</i> <i><u><b>Audio</b></u></i> <b>Pearl</b> <i>in this blog post that focuses on these concepts</i><b>)</b>.</li><li style="text-align: justify;"><span style="font-size: medium;"><span><b><a href="https://ecg-interpretation.blogspot.com/2019/05/ecg-blog-164-pacs-blocked-pacs.html" target="_blank">ECG Blog #164</a></b><span style="font-family: arial;"> — Reviews a case of <i>typical</i> <b>Mobitz I 2nd-Degree AV Block (</b><i>with detailed discussion of the <b>"Footprints" </b>of Wenckebach</i><b>)</b>.</span></span></span></li><li style="text-align: justify;"><span style="font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/11/ecg-blog-259-71-what-is-dual-level-block.html" target="_blank">ECG Blog #259</a></b> — and <b><a href="https://ecg-interpretation.blogspot.com/2022/11/ecg-blog-347-why-non-conducted-p-waves.html" target="_blank">ECG Blog #347</a></b> – Reviews the concept of <b><i><span style="color: red;">D</span>ual-<span style="color: red;">L</span>evel </i><span style="color: red;">A</span>V <span style="color: red;">B</span>lock</b>.</span></li><li style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;">The </span><b><a href="https://hqmeded-ecg.blogspot.com/2021/10/acute-pulmonary-edema-pea-arrest-lbbb.html" target="_blank">October 25, 2021</a> post</b><span style="font-family: arial;"> in Dr. Smith's ECG Blog — My Comment (</span><i>at the bottom of the page</i><span style="font-family: arial;">) reviews my approach to another case of a </span><b><i>Dual-Level</i> Wenckebach block</b><span style="font-family: arial;">.</span><b><span style="font-family: arial;"> </span></b></span></li><li style="text-align: justify;"><span style="font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/05/ecg-blog-226-42-variable-form-of.html" target="_blank">ECG Blog #226</a></b><span style="font-family: arial;"> — Works through a complex </span><b>Case Study</b> of <i>dual-level</i> AV block.</span></li><li style="text-align: justify;"><span style="font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/07/ecg-blog-243-47-why-group-beating-av.html" target="_blank">ECG Blog #243</a></b><span style="font-family: arial;"> — Reviews a case of <b>AFlutter</b> with </span><b><i>Dual-Level</i></b><span style="font-family: arial;"> </span><b>Wenckebach</b><span style="font-family: arial;"> out of the </span><b>AV Node</b><span style="font-family: arial;">.</span></span></li><li style="text-align: justify;"><br /></li><li style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/12/ecg-blog-267-75-group-beating-and.html" target="_blank">ECG Blog #267</a></b> — Reviews a case with <b><i><u>dual</u></i> AV nodal pathways</b>.</span></span></li></ul><p style="text-align: left;"></p><p class="MsoNormal"><span style="color: #333333; font-family: arial; font-size: medium;">==================================</span></p></div></div></span></span></div></div><div class="separator" style="clear: both; text-align: center;"></div><div><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></div><div class="separator" style="clear: both; text-align: center;"><div style="text-align: left;"><div class="separator" style="clear: both; text-align: center;"></div><span style="font-family: arial; font-size: medium;"> <br /><div style="text-align: justify;"><b><u><span face="Arial, sans-serif" style="color: red;">A</span></u></b><span face="Arial, sans-serif"><b style="text-decoration: underline;">DDENDUM</b><b> </b><b style="text-decoration: underline;"><span style="color: red;">(</span></b><i>10/14/2023</i><b><span style="color: red;">)</span>:</b></span></div><div style="text-align: justify;"><span face="Arial, sans-serif"><b><br /></b></span></div></span></div><div style="text-align: left;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial; font-size: medium; text-align: left;"></span></p><div><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: center;"><div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM6IE0axC-_2vJMD4d9lTnIIy2zqJZkybwADlcZyqs9SldX9AUMWa62snq9l2lgm14vb-Gtc47amXBkyV69cZd9C7oNg2BCBeRl64i1sHZm2e3DCYB5fs4bv04vDojyI5H7FabD9EOiu0/s2222/ECG-MP-52+-+2nd+Degree+AV+Blocks+%25286-24.1-2021%2529.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="462" data-original-width="2222" height="84" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgM6IE0axC-_2vJMD4d9lTnIIy2zqJZkybwADlcZyqs9SldX9AUMWa62snq9l2lgm14vb-Gtc47amXBkyV69cZd9C7oNg2BCBeRl64i1sHZm2e3DCYB5fs4bv04vDojyI5H7FabD9EOiu0/w400-h84/ECG-MP-52+-+2nd+Degree+AV+Blocks+%25286-24.1-2021%2529.png" width="400" /></a></div></div><div style="text-align: center;"><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><iframe allowfullscreen='allowfullscreen' webkitallowfullscreen='webkitallowfullscreen' mozallowfullscreen='mozallowfullscreen' width='320' height='266' src='https://www.blogger.com/video.g?token=AD6v5dxC1WJ4d78tkM1KviMKnXbEgEt3q-s6vyTOfojWln54weXcepjF6Cah90T87bYiuMImzxBwb647Ii533v8Ssw' class='b-hbp-video b-uploaded' frameborder='0'></iframe></span></div><span style="font-family: arial;"><div style="text-align: justify;"><span style="font-size: medium;">This <b>15</b>-minute <b>ECG Video (<span style="color: red;">M</span>edia <span style="color: red;">P</span>EARL <span style="color: red;">#</span>52)</b> — Reviews the <b>3 Types</b> of <b>2nd-Degree AV Block</b> — <u>plus</u> — the <i>hard-to-define</i> term of <b><i>"high-grade"</i></b> <b>AV block</b>. I supplement this material with the following 2 PDF handouts.</span></div><div style="text-align: justify;"><ul style="text-align: left;"><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://www.dropbox.com/s/v01yvlqafd5c6z2/AV%20Blocks-Pg%2060-66%20ECG-PB%20%281-16.22-2021%29-USE.pdf?dl=0" target="_blank">Section 2F</a> (</b><i>6 pages = the <b>"<u>short</u>" Answer</b></i><b>)</b> from my ECG-2014 Pocket Brain book provides quick written review of the <b>AV Blocks (</b><i>This is a free download</i><b>)</b>.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><a href="https://www.dropbox.com/s/k1jk1y4o4uu48ab/20.0-%20ACLS-2013-e-PUB-AV%20Block-Dissociaton-%2810-15.11-2014%29-LOCK.pdf?dl=0" target="_blank">Section 20</a></b> </span><b>(</b><i>54 pages = the <b>"<u>long</u>" Answer</b></i><b>)</b> from my ACLS-2013-Arrhythmias <i>Expanded</i> Version provides <i>detailed</i> discussion of <i>WHAT</i> the <b>AV Blocks</b> are — and what they are <u>not</u>! <b>(</b><i>This is a free download</i><b>)</b>.</span></li></ul><div><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><ul><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://dl.dropbox.com/s/p5o4fsrvt6mzqv3/z-ECG%20Audio%20Pearl-4%20%282-12.1-2021%29-USE-Faster.m4a?dl=0" target="_blank">ECG Media Pearl #4</a></b><span> <b>(</b><i>4:30 minutes <u><b>Audio</b></u></i><b>) </b>— The <b><span style="color: red;">A</span>V <span style="color: red;">B</span>locks</b> & <i>When to Suspect <b>Mobitz I </b></i></span></span><b> </b>— <i>See</i> <b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-186-audio-pearl-4-av-blocks.html" target="_blank">ECG Blog #186</a></b> —</li></ul></span></div></div></div></span></div></div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><p></p></span></div></div></div></div></div><div><br /></div><div><br /></div><div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; font-size: medium;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/s613/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgp88BgXFKRpq-xfnPyzH1moIhPFsF718XgFXAsoogXdZnWBpE1YliOPA64KGC1OeM8NKdYHJp9FWjncuw3_xXmp8MsDKghQyMwVNEpNvr94VdIvYGIulf5n-F9cCBeILhbQGhJI8nf3zc/w400-h16/0++-+Figure-6-RED+LINE-+Use+in+Blogs.png" width="400" /></a></span></div><div class="separator" style="clear: both; text-align: center;"><br /></div><div class="separator" style="clear: both; text-align: justify;"><p class="MsoNormal" style="margin: 0in;"><br /></p><p class="MsoNormal" style="margin: 0in;"><br /></p><p class="MsoNormal" style="margin: 0in;"><br /></p></div></div></div></span>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com0tag:blogger.com,1999:blog-3364570834099131201.post-41347637915716877082023-10-07T00:04:00.004-04:002023-10-07T09:01:35.239-04:00ECG Blog #398 — Uncontrolled Graves Disease ... <span style="font-family: arial; font-size: medium;"><br /><div style="text-align: justify;">The ECG in <u style="font-weight: bold;">Figure-1</u> was obtained from a middle-aged woman who presented with <b><i>"palpitations"</i></b>. Of note — she has a history of <b><i>untreated</i></b> <b>hyperthyroidism</b>.</div></span><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>QUESTIONS:</u></b></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;"><i style="text-align: left;">How would YOU interpret the rhythm</i><span style="text-align: left;"> in </span><u style="text-align: left;">Figure-1</u><span style="text-align: left;">?</span></span></li><li><span style="font-family: arial; font-size: medium;"><span style="text-align: left;">Can you explain the </span><i style="text-align: left;"><u>atrial</u></i><span style="text-align: left;"> activity in this rhythm strip?</span></span></li></ul></div><div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiSarZJmPjEKfXETBVVAepop5XSl9bAqGeUH733cBrHTzTvlFoNcgG-9adeFuj9688AHU2p9vIzB8O-wpzuN7pCxtYGb-F9wgVCvfPgs0ePP7OaUM5Vcl3xTyMuyKO4HJD1_vaB-gJYZBQardlWdQ0rCl87X-2baQoa47CB5IHSYOr5K1U31b_179YWKY/s3186/Figure-1%20ECG-1%20%20Lead%20II%20(8-18.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="738" data-original-width="3186" height="93" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiSarZJmPjEKfXETBVVAepop5XSl9bAqGeUH733cBrHTzTvlFoNcgG-9adeFuj9688AHU2p9vIzB8O-wpzuN7pCxtYGb-F9wgVCvfPgs0ePP7OaUM5Vcl3xTyMuyKO4HJD1_vaB-gJYZBQardlWdQ0rCl87X-2baQoa47CB5IHSYOr5K1U31b_179YWKY/w400-h93/Figure-1%20ECG-1%20%20Lead%20II%20(8-18.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: left;"><u>Figure-1:</u></b><span style="text-align: left;"> The initial long lead II rhythm strip in today's case.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><span><div style="text-align: justify;"><span style="font-family: arial; font-size: medium; text-decoration: underline;"><b><i>MY Approach</i> to the Rhythm in Figure-1:</b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;">As per <b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — I favor the <span style="color: red; text-decoration: underline;"><b>P</b></span><b>s, </b><span style="color: red; text-decoration: underline;"><b>Q</b></span><b>s, 3</b><span style="color: red; text-decoration: underline;"><b>R</b></span><b> Approach</b> for interpretation of the cardiac rhythm — beginning with <span style="text-decoration: underline;"><i>whichever</i></span> of these <b>5 <i>KEY </i>Parameters</b> is easiest to assess for the tracing in front of me:</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">At least in the single lead II rhythm strip seen in <u>Figure-1</u> — The <b><u>Q</u>RS complex</b> appears to be narrow.</span></li><li><span style="font-family: arial; font-size: medium;"><b><u>P</u> waves </b><u style="font-style: italic;">are</u> <b>present (</b><i>See PEARL #1 below</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;">The rhythm in today's tracing is <u style="font-style: italic;"><b>not</b></u> <b><u>R</u>egular</b>. The <b><u>R</u>ate</b> of the rhythm varies because of this irregularity — but the overall ventricular rate is <b><i>a bit over</i> 100/minute (</b>ie, <i>most R-R intervals are slightly less than 3 large boxes in duration</i><b>)</b>. </span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><u style="font-weight: bold;">NOTE:</u> For the moment, I will defer addressing the last of the 5 <i>KEY</i> Parameters </span><span style="font-family: arial;">— which is to determine if </span><b><u>P</u> waves</b><span style="font-family: arial;"> are (</span><i>or are not</i><span style="font-family: arial;">) </span><span style="font-family: arial; font-style: italic; font-weight: bold;"><u>R</u>elated</span><span style="font-family: arial;"> to neighboring QRS complexes.</span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><br /></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><br /></b></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><div><span><b><u>PEARL <span style="color: red;">#</span>1:</u></b></span> After considering the 5 <i>KEY</i> Parameters — the <i>EASIEST</i> next step for determining the mechanism of a complex rhythm — is to <b><i><u>label</u> the P waves</i></b><i>.</i></div><div><ul><li><i>RED</i> arrows in <u style="font-weight: bold;">Figure-2</u> — highlight those <b>P waves</b> that we can readily identify.</li><li><br /></li><li>I've colored the 1st and 3rd arrows in <u>Figure-2</u> in <i>PINK, </i>because while not as obvious — it should be apparent that these <i>PINK</i> arrows <u style="font-style: italic;">also</u> highlight <b><i>"extra"</i></b> <b>deflections </b>that are <b>P waves</b> <b>(</b>ie, <i>in the partially seen T wave at the very onset of this rhythm strip <u>and</u> distorting the initial upstroke of the R wave of beat #2</i><b>)</b>.</li><li><br /></li><li><i>Isn't it EASIER to at least assess the rhythm in <u>Figure-2</u> — now that all P waves are labeled?</i></li></ul><div><br /></div></div><div><b><u>NOTE:</u></b> Although the most common cause of <i>unexpected</i> pauses in a rhythm is the occurrence of one or more <i>blocked</i> PACs — I do <i><u>not</u></i> see distortions in any ST-T wave of this single-lead rhythm strip that might be consistent with blocked PACs.</div><div><ul><li>Instead — the <b>P wave morphology</b> in <u>Figure-2</u> that we see highlighted by each of the arrows <b>is the same</b>. This suggests that we are dealing with a <b><i><u>single</u></i> atrial focus </b>that is both <b><i>irregular</i></b> <u>and</u> <b><i>firing</i></b> <b>rapidly!</b></li><li><b><br /></b></li><li>In support that the underlying atrial rhythm is <b>ATach (</b><i><u>A</u>trial <u>T</u>achycardia</i><b>)</b> — is that we see <b>3 P waves <i>in a row</i></b> with similar P wave morphology and a similar P-P interval at the beginning of the tracing (<i>between beats #1-to-#3</i>) — and then <b>4 P waves <i>in a row</i></b> with similar P wave morphology and a similar P-P interval near the end of the tracing (<i>between beats #8-to-10</i>).</li><li>That said — there clearly <u>is</u> variation in the P-P interval in other parts of today's tracing.</li></ul></div></span></div></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span><b><u>PEARL <span style="color: red;">#</span>2:</u></b> It is important to be aware that <b><i>"</i></b></span><u><b><i>not</i></b></u><span><b><i> every arrhythmia obeys the rules!"</i></b> As a result — We sometimes need to think <i>"out of the box"</i> in order to come up with the most plausible explanation for a given arrhythmia. </span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">Examples of conditions notorious for producing arrhythmias that <i>"do <u>not</u> obey the rules"</i> include: <b>i<span style="color: red;">)</span> Hyperkalemia (</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2022/01/ecg-blog-275-58-what-chart-audit.html" target="_blank">ECG Blog #275</a>)</b>; <b>ii<span style="color: red;">)</span> Cardiac arrest</b>; <u>and</u>, <b>iii<span style="color: red;">)</span> Vagotonic Block (</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2013/02/ecg-interpretation-review-61-av-block.html" target="_blank">ECG Blog #61</a>)</b>.</span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">Today's case, in which the patient had <b><i><u>untreated</u></i></b> <b>hyperthyroidism</b> — presents one more condition that may be associated with unusual forms of common arrhythmias that <i>"do <u>not</u> obey the usual rules"</i>.</span></li></ul></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><u>PEARL <span style="color: red;">#</span>3:</u></b> Although <b>ATach </b>is usually a fairly regular atrial rhythm — there may at times be some irregularity. That said — <b>I do <i><u>not</u></i> recall ever seeing as much irregularity</b> in the atrial rhythm of a patient with ATach as we see in today's tracing.</span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">As noted in Pearl #2 — it is likely that the reason for this excessive degree of irregularity in today's ATach rhythm, is the result of this patient's <b><i><u>uncontrolled</u></i></b> <b>hyperthyroidism</b>.</span></li><li><span style="font-family: arial; font-size: medium;">Use of <b>ß-blocker therapy (</b><i>oral and IV as needed for rate control</i><b>)</b> — is the usual treatment of choice for sinus tachycardia <i>and/or</i> other SVT rhythms associated with hyperthyroidism. The <i>"good news"</i> — is that once this patient's thyroid condition comes under control — the atrial tachyarrhythmia will probably resolve.</span></li></ul></div><div><span style="font-size: medium;"><br /></span></div><div><span style="font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTTZDo4Km7fk3XOw7zTXRL_93JxD9FLahFl43dcwTA9zYLAYyL7L4lD58NtYAL9kj-UxuW_DAwJ2KR5zBd1SzyG7LdPyzGFekhTiufRgcK0WcGoAzuR3e2ge-SvrU4ppSc-QX2nvofbZXToVReIjMRwBXxozeYG8DjSZEIfEQmnSxTF8fRuYdO1PLieTM/s3188/Figure-2%20ECG-1%20%20Lead%20II%20P%20waves(10-2.24-2023)-USE%20copy.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="734" data-original-width="3188" height="93" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiTTZDo4Km7fk3XOw7zTXRL_93JxD9FLahFl43dcwTA9zYLAYyL7L4lD58NtYAL9kj-UxuW_DAwJ2KR5zBd1SzyG7LdPyzGFekhTiufRgcK0WcGoAzuR3e2ge-SvrU4ppSc-QX2nvofbZXToVReIjMRwBXxozeYG8DjSZEIfEQmnSxTF8fRuYdO1PLieTM/w400-h93/Figure-2%20ECG-1%20%20Lead%20II%20P%20waves(10-2.24-2023)-USE%20copy.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: left;"><u>Figure-2:</u></b><span style="text-align: left;"> I've added <i>RED</i> arrows to <u>Figure-1</u> — to highlight those<b> P waves</b> that we can readily identify. The 1st and 3rd arrows (<i>in PINK</i>) — highlight deflections produced by partially "hidden" P waves (<i>See text</i>).</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><span><br /></span></span></div><div><span style="font-family: arial; font-size: medium;"><span><b><u><i><span style="color: red;">W</span>hat <span style="color: red;">T</span>hen</i> is the <i><span style="color: red;">R</span>hythm</i> in Figure-2<span style="color: red;">?</span></u></b></span></span></div><div style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><span>So far — We have only interpreted part of the rhythm in today's tracing. <i>What we <u>know</u> thus far:</i></span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial;"><span style="font-size: medium;">This patient has <b><i><u>uncontrolled</u></i></b> <b>hyperthyroidism</b> — and as a result (<i>as per Pearl #2</i>) — arrhythmias associated with this condition <i>"may <u>not</u> obey the usual rules"</i>.</span></span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">That said —<b style="font-style: italic;"> WHY is the ventricular rhythm so irregular?</b></span></li></ul><div><span style="font-family: arial; font-size: medium;"><b><br /></b></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><br /></u></b></span></div><div><span style="font-family: arial; font-size: medium;"><b><u>PEARL <span style="color: red;">#</span>4:</u></b> It is extremely common to see <b><i>Wenckebach</i></b> <b>conduction</b> in patients with ATach. As a result — I <u style="font-style: italic;">always</u> look for this possibility whenever I see irregularity in a patient with ATach. <i>What we <u>know</u>:</i></span></div><div><ul><li><span style="font-family: arial; font-size: medium;">The PR interval before <b>beats #4</b>, <b>5</b> and <b>11</b> looks to be the same — which strongly suggests that <i>at least these 3 beats <u>are</u></i> conducting!</span></li><li><span style="font-family: arial; font-size: medium;">There are other PR intervals <b>(</b>ie, <i>the PR interval before beat #3</i><b>)</b> — that are slightly longer — which makes me consider the possibility of <b><i>some</i></b> <b>form</b> of <b><i>Wenckebach</i></b> <b>conduction</b> in this patient with ATach.</span></li></ul><div><span style="font-family: arial; font-size: medium;"><br /></span></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u>NOTE:</u></b> <i>I wish I had a simultaneously-recorded 12-lead tracing</i>. Lacking this — I assumed that all 12 QRS complexes seen in today's rhythm strip were supraventricular, even though some of these beats are noticeably taller than others in this single monitoring lead.</span></div><div><ul><li><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">B</span>OTTOM <span style="color: red;">L</span>ine<span style="color: red;">:</span></u></b> At this point in the process — I suspected that today's rhythm represented an <b><i>unusual</i> form</b> of <b>ATach</b>, in which there was <i>marked irregularity</i> in the atrial rhythm <b>(</b><i>as a result of this patient's uncontrolled hyperthyroidism</i><b>)</b> — with <b><i>some</i></b> <b>form</b> of <b>Wenckebach</b> <b>conduction</b> accounting for much of the rhythm irregularity and variation in PR intervals.</span></li><li><span style="font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><b><u>To EMPHASIZE:</u></b> The above <i>"Bottom Line"</i> interpretation of today's rhythm, which is admittedly general — <i><u>is</u></i> <u>enough</u> for appropriate clinical management. The reason that this <i><u>is</u></i> all that is needed clinically — is the knowledge that <b><i>today's rhythm will probably resolve once this patient's hyperthyroidism is treated</i></b>.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;">The said, in my intellectual desire to better understand the likely mechanism of today's rhythm — I thought the best way to explore this would be to <b><i>devise a</i></b> <b><u><span style="color: red;">L</span>addergram</u></b>. </span></li></ul></div></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;">======================================</span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">L</span>ADDERGRAM <span style="color: red;">I</span>llustration<span style="color: red;">:</span></u></b></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;"><div style="font-family: -webkit-standard;"><ul><li><span style="font-family: arial; font-size: medium;">Sequential legends over the next 5 Figures illustrate my thought process as I derived the <b><i><u>laddergram</u></i></b> that I propose in sequential <b><u>Figures-3</u></b> <b><i>thru</i></b> <b><u>-7</u></b>. <b>(</b><i>See </i><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b><i> for review on how to read and/or draw Laddergrams</i><b>)</b>.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-family: arial; font-size: medium;"><b><u>To EMPHASIZE</u></b> — Today's laddergram was <i><u>not</u></i> easy to draw — because as emphasized above, today's rhythm does <u style="font-style: italic;">not</u> obey the usual rules. That said — my hope is that even clinicians with limited experience reading laddergrams will be able to follow these sequential figures. <i>Stay with me!</i></span></li></ul></div><div style="font-family: -webkit-standard;"><br /></div></span></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDj5n05LQNd-hLc3nR4liXAhXizwBA6hfN6KiRM7gcxzfZRgHmr2j_r8GXh0033BNDmVHmv-WnRtoP3GD8DTJLvQ8mN_Hmh8jFKBhKFMmKGprUSX3Q2xoCb2SXIqedIX0GkcfwOy3ew_phhzsngHSLHgF0v38J3vDcr4PRn90NA9M5c9VRb_Ze-n4eos8/s3718/Figure-3%20%20Ladder-1%20(8-18.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1734" data-original-width="3718" height="186" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDj5n05LQNd-hLc3nR4liXAhXizwBA6hfN6KiRM7gcxzfZRgHmr2j_r8GXh0033BNDmVHmv-WnRtoP3GD8DTJLvQ8mN_Hmh8jFKBhKFMmKGprUSX3Q2xoCb2SXIqedIX0GkcfwOy3ew_phhzsngHSLHgF0v38J3vDcr4PRn90NA9M5c9VRb_Ze-n4eos8/w400-h186/Figure-3%20%20Ladder-1%20(8-18.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-3:</u></b><span style="text-align: left;"> </span></span><span style="font-family: arial; text-align: justify;">It is usually easiest to begin a laddergram by marking the path of </span><b style="font-family: arial; text-align: justify;"><i>sinus</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">P waves</b><span style="font-family: arial; text-align: justify;"> through the </span><b style="font-family: arial; text-align: justify;"><i>Atrial</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">Tier (</b><i style="font-family: arial; text-align: justify;">RED lines drawn directly below the onset of each of the P waves — as shown by the large BLUE arrows</i><b style="font-family: arial; text-align: justify;">)</b><span style="font-family: arial; text-align: justify;">. Note that these </span><i style="font-family: arial; text-align: justify;"><u>RED</u></i><span style="font-family: arial; text-align: justify;"> lines in the </span><i style="font-family: arial; text-align: justify;">Atrial</i><span style="font-family: arial; text-align: justify;"> Tier are nearly vertical — since conduction of sinus P waves through the atria is rapid. As mentioned earlier — <i>the atrial rhythm is <u>not</u> regular</i>.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLW5TkpjeX3tX00P6KvxXdpLvgAL5H4Ut8A8frtdESEVJw9NtnFK55pgf3Y51qQmtkQPO_zJurqCoS_dryBy9mBbpVvM1S83cLF6waT987Y0lg7XTo0loaHpiFpQuVFN0H-YN15AwZfnTDgxggDzP_yPYthYUh5oMGqKP_NrRAHLtAmyRZFXialdHsiu4/s3726/Figure-4%20%20Ladder-2%20(8-18.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1776" data-original-width="3726" height="191" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLW5TkpjeX3tX00P6KvxXdpLvgAL5H4Ut8A8frtdESEVJw9NtnFK55pgf3Y51qQmtkQPO_zJurqCoS_dryBy9mBbpVvM1S83cLF6waT987Y0lg7XTo0loaHpiFpQuVFN0H-YN15AwZfnTDgxggDzP_yPYthYUh5oMGqKP_NrRAHLtAmyRZFXialdHsiu4/w400-h191/Figure-4%20%20Ladder-2%20(8-18.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-4:</u></b><span style="text-align: left;"> </span></span><span style="font-family: arial; text-align: justify;">The most challenging part of most laddergrams is construction of the AV Nodal Tier — so </span><i style="font-family: arial; text-align: justify;">I typically save that for last</i><span style="font-family: arial; text-align: justify;">. Therefore, after drawing in all P waves into the </span><i style="font-family: arial; text-align: justify;">Atrial</i><span style="font-family: arial; text-align: justify;"> Tier — It's easiest to next add indication of all narrow (ie, </span><i style="font-family: arial; text-align: justify;">conducting</i><span style="font-family: arial; text-align: justify;">) QRS complexes into the </span><b style="font-family: arial; text-align: justify;"><i>Ventricular</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">Tier</b><span style="font-family: arial; text-align: justify;">. The large </span><i style="font-family: arial; text-align: justify;">BLUE</i><span style="font-family: arial; text-align: justify;"> arrows show that I use the </span><i style="font-family: arial; text-align: justify;">onset</i><span style="font-family: arial; text-align: justify;"> of each QRS as my landmark. Note that the </span><i style="font-family: arial; text-align: justify;">RED</i><span style="font-family: arial; text-align: justify;"> lines in the Ventricular Tier are also nearly vertical — since conduction of these </span><b style="font-family: arial; text-align: justify;"><i>narrow</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">QRS complexes</b><span style="font-family: arial; text-align: justify;"> through the ventricles is rapid.</span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /><span><br /></span></span></div><div><br /></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpXRgRds9nlE_qEnJUIO_InPwfYNZuneX27Ss-ueI5aH7RfEJ4ZVuYosHT4hM7KHe0pW_fnXKH3extgzbulq95vdlLfE5MPOCVFjHzoX0oaW6WMwhXr_iCNMuKWCdwAsSSCu-z4Sdt4cIlaIJr0GO6fENr4ikhZgWVFMnU-C0iv58YiQ9PgeTZOqgE6nA/s3730/Figure-5%20%20Ladder-3%20(8-18.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1792" data-original-width="3730" height="193" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhpXRgRds9nlE_qEnJUIO_InPwfYNZuneX27Ss-ueI5aH7RfEJ4ZVuYosHT4hM7KHe0pW_fnXKH3extgzbulq95vdlLfE5MPOCVFjHzoX0oaW6WMwhXr_iCNMuKWCdwAsSSCu-z4Sdt4cIlaIJr0GO6fENr4ikhZgWVFMnU-C0iv58YiQ9PgeTZOqgE6nA/w400-h193/Figure-5%20%20Ladder-3%20(8-18.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-5:</u></b><span style="text-align: left;"> </span></span><span style="font-family: arial; text-align: justify;">It's time to </span><b style="font-family: arial; text-align: justify;"><i>begin</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">"solving"</b><span style="font-family: arial; text-align: justify;"> what we can in the laddergram. I do this by connecting P waves in the </span><b style="font-family: arial; text-align: justify;"><i>Atrial</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">Tier</b><span style="font-family: arial; text-align: justify;"> that might </span><i style="font-family: arial; text-align: justify;"><u>logically</u></i><span style="font-family: arial; text-align: justify;"> be conducting — to </span><i style="font-family: arial; text-align: justify;">narrow</i><span style="font-family: arial; text-align: justify;"> QRS complexes in the </span><b style="font-family: arial; text-align: justify;"><i>Ventricular</i></b><span style="font-family: arial; text-align: justify;"> </span><b style="font-family: arial; text-align: justify;">Tier</b><span style="font-family: arial; text-align: justify;">. </span><br style="font-family: arial; text-align: justify;" /><span style="font-family: arial; text-align: justify;">— — — —</span><br style="font-family: arial; text-align: justify;" /><span style="font-family: arial; text-align: justify;">Because of the complexity of today's rhythm — I had to make assumptions that would need to be "tested out". As per PEARL #4 — I thought it most logical that <b>beats #4,5,11</b> <i><u><b>are</b></u></i> <b>conducted</b> to the ventricles <b>(</b><i>because the PR interval preceding each of these beats is the same — and that is unlikely to occur by chance</i><b>)</b>. I added some additional light <i>BLUE</i> lines <b>(</b><i>before <b>beats #1,2,3; 6</b>; and <b>10</b> — because I thought it logical that the P waves preceding these beats would <u>also</u> be likely to conduct</i><b>)</b>.<br /><br /></span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><br /></div><div><br /></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiosLb_E22NEOyEeXhvLTMkSbDASqXM-3xFwbHiGZA9IXce-Hp5xaib0CFNZJ70sz0iCjm-BnAnIJi5uaK7NXEJN_TLe_NfzI7EePmRqwBgTly5j2lmtUBc-0yh8yjrLGceSo-w8X5Zp8nk8mEt7sSgCl4EjwhBcqLQSU3oAfQ0AQkUor4xrnR5RI2tzLg/s3734/Figure-6%20%20Ladder-4%20(8-18.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1790" data-original-width="3734" height="191" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiosLb_E22NEOyEeXhvLTMkSbDASqXM-3xFwbHiGZA9IXce-Hp5xaib0CFNZJ70sz0iCjm-BnAnIJi5uaK7NXEJN_TLe_NfzI7EePmRqwBgTly5j2lmtUBc-0yh8yjrLGceSo-w8X5Zp8nk8mEt7sSgCl4EjwhBcqLQSU3oAfQ0AQkUor4xrnR5RI2tzLg/w400-h191/Figure-6%20%20Ladder-4%20(8-18.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><span style="font-family: arial;"><b style="text-align: left;"><u>Figure-6:</u></b></span><span style="font-family: arial; text-align: justify;"> As more and more of the AV Nodal Tier is filled in — the possibilities for alternatives lessen. I therefore added the 4 new light <i>BLUE</i> lines that we see in <u>Figure-6</u>. Even though the PR intervals proposed in this laddergram for <b>beats #7,8,9 </b>are long — I see <i>no alternative explanation</i> for <b>P waves h,i,j</b> and <b>o</b> — than for these P waves to be conducting to produce QRS <b>beats #7,8,9</b> and <b>12</b>.<br />— — — —<br />This leaves the 4 <i>BLUE</i> arrow P waves <b>(</b><i> = P waves c,k,l and p</i><b>)</b>. I thought it logical to propose that <b>P waves c</b> and <b>p</b> do <i><u>not</u></i> make it out of the AV Nodal Tier. This leaves us with the remaining 2 <i>BLUE</i> arrow P waves <b>(</b><i> = P waves k and l</i><b>)</b>.<br /><br /></span></span></td></tr></tbody></table></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><br /></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAXTD0w2LB1Df-5t3ChtUMIceXfoLJUbv07iw-9V5SJvoobOukrcEFo9Q1SqvYieRoOh__D-sIESlHtU7AbtOHD2cVeYEtkxpaWk_s5AKrcZISbov81q6BTHPAkBsZgZTubQ5JrlZwTNaGyRqM356hr7vkEZBlINRSuS0XT7Yw-46hJjwtVxgdYVyvTVU/s3728/Figure-7%20%20Ladder-5%20(8-25.21-2023)-USE.png" style="margin-left: auto; margin-right: auto;"><span style="font-family: arial; font-size: medium;"><img border="0" data-original-height="1792" data-original-width="3728" height="193" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAXTD0w2LB1Df-5t3ChtUMIceXfoLJUbv07iw-9V5SJvoobOukrcEFo9Q1SqvYieRoOh__D-sIESlHtU7AbtOHD2cVeYEtkxpaWk_s5AKrcZISbov81q6BTHPAkBsZgZTubQ5JrlZwTNaGyRqM356hr7vkEZBlINRSuS0XT7Yw-46hJjwtVxgdYVyvTVU/w400-h193/Figure-7%20%20Ladder-5%20(8-25.21-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-family: arial; font-size: medium;"><b style="text-align: left;"><u>Figure-7:</u></b><span style="text-align: left;"> Step back a bit from this laddergram: <i>Doesn't the generally increasing PR intervals seen for beats #5-thru-9, followed by </i><b style="font-style: italic;"><u>non</u>-conduction</b><i> of </i><b style="font-style: italic;">P wave k</b><i> — make for a credible </i><b style="font-style: italic;">Wenckebach</b> <b style="font-style: italic;">sequence? </b>Similarly — <i>Doesn't the increasing PR interval from beats #11-to-12, followed by non-conduction of P wave p — make for a credible 3:2 AV Wenckebach sequence?</i><br /><span style="text-align: justify;">— — — —<br />This leaves us with <b>P wave l </b>— which is a P wave <i><u>without</u></i> any possibility of conducting. <i>Retrograde conduction </i>from P wave k <b>(</b><i>the dotted BLUE line ending in a butt end</i><b>)</b> could account for failed conduction of P wave l.</span></span></span></td></tr></tbody></table><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-size: medium;"><span style="font-family: arial;"><br /></span></span></div><div><span style="font-size: medium;"><span style="font-family: arial;">=======================================</span></span></div><div><span style="font-family: arial; font-size: medium;"><b><i><u><span style="color: red;">P</span>utting <span style="color: red;">I</span>t <span style="color: red;">A</span>ll <span style="color: red;">T</span>ogether<span style="color: red;">:</span></u></i></b></span></div><div style="text-align: justify;"><ul><li><span style="font-size: medium;"><span style="font-family: arial;"><b><u>PEARL <span style="color: red;">#</span>5:</u></b> On occasion — certain complex arrhythmias will defy precise description of their mechanism from the surface ECG. The "Pearl" — is to realize <b><i>that this does <u>not</u> matter!</i></b> What counts — is the <i>"theme"</i> of the rhythm. </span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;"><br /></span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;">The <i><b>"<u>theme</u>"</b></i> of today's rhythm — is that in this patient with <u style="font-style: italic;">uncontrolled</u> hyperthyroidism — there is a <b>markedly <i>irregular</i> ATach</b> with periods of <b><i>Wenckebach</i></b> <b>conduction</b> out of the AV Node. Because today's rhythm does <u style="font-style: italic;">not</u> obey the usual rules — it is probably <u style="font-style: italic;">not</u> worth the time and effort trying to attain a more precise rhythm diagnosis.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;"><br /></span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;">As noted above for the other conditions I cite in Pearl #2 — <b>IF the underlying (</b><i>causative</i><b>) condition can be corrected — the </b></span><span style="font-family: arial;"><b>arrhythmia will usually resolve!</b> This is especially true in today's case, in that IF this patient's thyroid condition can be controlled — <i><u>both</u></i> the irregular ATach <u>and</u> the intermittent Wenckebach conduction will probably resolve.</span></span></li></ul></div><div><br /></div><div><br /></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial;"><div style="text-align: justify;"><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span style="font-family: arial;">==================================<o:p></o:p></span></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="font-family: arial;"><b><u><span style="color: red;">A</span></u></b><b><u>cknowledgment<span style="color: red;">:</span></u></b> My appreciation to Hao Nguyen (<i>from Cao Lãnh, Vietnam</i>) for the case and this tracing. <o:p></o:p></span></p><p class="MsoNormal" style="margin: 0in; text-align: justify;"><span style="color: #333333;"><span style="font-family: arial;">==================================</span></span></p></span></div><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><p class="MsoNormal" style="margin: 0in; text-align: justify;"><br /></p></span></div></div><div style="text-align: justify;"><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><span style="font-family: arial; font-size: medium;"><div><div style="text-align: justify;"><div><span style="font-family: arial;"><b><i><u><span style="color: red;">R</span></u></i></b><b><i><u>elated</u></i></b><b><u> <span style="color: red;">E</span>CG <span style="color: red;">B</span>log <span style="color: red;">P</span>osts to <i>Today’s</i> Case<span style="color: red;">:</span></u></b></span></div><div><p class="MsoNormal" style="margin: 0in;"></p><ul><li style="text-align: justify;"><span style="font-family: arial;"><b><a href="https://ecg-interpretation.blogspot.com/2021/03/ecg-blog-205-ecg-mp-23-what-is.html" target="_blank">ECG Blog #205</a> </b>— Reviews my <b><i><span style="color: red;">S</span>ystematic</i></b> <b><span style="color: red;">A</span>pproach</b> to 12-lead ECG Interpretation.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-185-audio-pearl-3-ps-qs-3r.html" target="_blank">ECG Blog #185</a></b> — Review of the <b><span style="color: red;"><u>P</u></span>s, <span style="color: red;"><u>Q</u></span>s, 3<span style="color: red;"><u>R</u></span> Approach</b> for systematic rhythm interpretation.</span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><br /></span></li><li style="text-align: justify;"><span style="font-family: arial; font-size: medium;"><b><a href="https://ecg-interpretation.blogspot.com/2021/01/ecg-blog-188-how-to-read-laddergrams.html" target="_blank">ECG Blog #188</a></b> — Reviews how to <b><i>read</i></b> <u>and</u> <b>draw Laddergrams </b></span><span style="font-family: arial; font-size: medium;"><b>(</b><i>w</i></span><i>ith LINKS to more than 90 laddergram cases — many with step-by-step sequential illustration</i><b>)</b>.</li></ul><div><br /></div></div></div></div><p class="MsoNormal"><span style="font-family: arial;"></span></p><div><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhcUanPtyekRxG_NN3M6G7ixBWDiaFwP9HSTmmxsiAGLgKFyGGIePOLicsrDGS_HrTpJuFvbsUgWw_X6ZXKehXoAeVAyPHHXStk2lmG9uzuY33nE1KZQCLDvOH1VKIkbTzKmck2XR3I6_wmONnxXQmAen5uT-Ez0rJCH23wswN1g0uETqzQQugv30VE=s613" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/a/AVvXsEhcUanPtyekRxG_NN3M6G7ixBWDiaFwP9HSTmmxsiAGLgKFyGGIePOLicsrDGS_HrTpJuFvbsUgWw_X6ZXKehXoAeVAyPHHXStk2lmG9uzuY33nE1KZQCLDvOH1VKIkbTzKmck2XR3I6_wmONnxXQmAen5uT-Ez0rJCH23wswN1g0uETqzQQugv30VE=w400-h16" width="400" /></a></span></div></div></span></span></div></div></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><span style="font-family: arial; font-size: medium;"><b><u><span style="color: red;">A</span>DDENDUM</u> (</b><i>10/7/2023</i><b>)<span style="color: red;">:</span></b></span></div><div style="text-align: justify;"><span style="font-size: medium;"><span style="font-family: arial;">I have just received an email from H.S. Cho = </span><span style="color: rgba(0, 0, 0, 0.85); font-family: "Helvetica Neue";">조현석</span><span style="font-family: arial;"> (<i>from Seoul, Korea</i>) — in which he questions whether instead of P wave <b>"m"</b> conducting <b>beat #10</b> — perhaps it is really P wave <b>"l" </b>that conducts. This is a reasonable theory — given that the PR interval from m-to-beat #10 <i>does</i> appear to be slightly <i><u>less</u></i> than the PR intervals that precede beats #4 and 5 (<i>and we <u>know</u> that P waves <b>e</b> and <b>f</b> are conducting</i>).</span></span></div><div style="text-align: justify;"><ul><li><span style="font-family: arial; font-size: medium;">What I also find very plausible about H.S. Cho's theory — is that laddergram events in beats #9 and 10 now look <i>similar</i> to laddergram events in beats #2 and 3.</span></li><li><span style="font-family: arial; font-size: medium;"><br /></span></li><li><span style="font-size: medium;"><span style="font-family: arial;"><u style="font-weight: bold;">BOTTOM Line:</u> As I emphasized earlier — the precise mechanism of this fascinating tracing is elusive. That said, <i><u>regardless</u></i> of which laddergram is "correct" — t</span><span style="font-family: arial;">he <b><i>"<u>theme</u>" </i></b>of today's rhythm remains that in this patient with <i><u>uncontrolled</u></i> hyperthyroidism — there is a <b>markedly <i>irregular</i> ATach</b> with periods of <b><i>Wenckekbach</i></b> <b>conduction</b> out of the AV Node.</span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;"><br /></span></span></li><li><span style="font-size: medium;"><span style="font-family: arial;">My <i>THANKS</i> to H.S. Cho for his very valid suggestion!</span></span></li></ul></div><div style="text-align: justify;"><span style="font-family: arial;"><span style="font-size: medium;"><br /></span></span></div><div style="text-align: justify;"><table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiz1NP-r26Zzy0ZXOmIde2karDNwZBfxE7X9AMCVfzOauZjBsp4wFj5F0c6mzHcVYIt6iB33pKVaSeI6ebgm6BCp0JOxnh12A2JF86FIhIjU8vzQ_4yKLTnSE61LPKIjl4EZIxAJmdgf1wCO3TkIAXUlX4gLzQE6ry2foq4gBM5DUyEWTrfAQHTsGEB22I/s3688/Figure-8%20-%20from%20H.S.%20Cho%20(10-7.1-2023)-USE.png" imageanchor="1" style="margin-left: auto; margin-right: auto;"><span style="font-size: medium;"><img border="0" data-original-height="1786" data-original-width="3688" height="194" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiz1NP-r26Zzy0ZXOmIde2karDNwZBfxE7X9AMCVfzOauZjBsp4wFj5F0c6mzHcVYIt6iB33pKVaSeI6ebgm6BCp0JOxnh12A2JF86FIhIjU8vzQ_4yKLTnSE61LPKIjl4EZIxAJmdgf1wCO3TkIAXUlX4gLzQE6ry2foq4gBM5DUyEWTrfAQHTsGEB22I/w400-h194/Figure-8%20-%20from%20H.S.%20Cho%20(10-7.1-2023)-USE.png" width="400" /></span></a></td></tr><tr><td class="tr-caption" style="text-align: center;"><span style="font-size: medium;"><b style="font-family: arial; text-align: left;"><u>Figure-8:</u></b><span style="font-family: arial; text-align: left;"> I've redrawn my <u>Figure-7</u> — to illustrate H.S. Cho's alternative theory for events in the latter part of this tracing.</span></span></td></tr></tbody></table><span style="font-size: medium;"><br /></span><span style="font-family: arial; font-size: large;"><br /></span></div><div><br /></div><div><span style="font-family: arial; font-size: medium;"><div style="font-family: -webkit-standard;"><span style="font-family: arial;"><div style="text-align: justify;"><div style="text-align: left;"><span style="font-family: arial; font-size: medium;"><span style="font-family: arial; font-size: medium;"><div class="separator" style="clear: both; text-align: center;"><span style="font-family: arial; margin-left: 1em; margin-right: 1em;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhcUanPtyekRxG_NN3M6G7ixBWDiaFwP9HSTmmxsiAGLgKFyGGIePOLicsrDGS_HrTpJuFvbsUgWw_X6ZXKehXoAeVAyPHHXStk2lmG9uzuY33nE1KZQCLDvOH1VKIkbTzKmck2XR3I6_wmONnxXQmAen5uT-Ez0rJCH23wswN1g0uETqzQQugv30VE=s613" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="24" data-original-width="613" height="16" src="https://blogger.googleusercontent.com/img/a/AVvXsEhcUanPtyekRxG_NN3M6G7ixBWDiaFwP9HSTmmxsiAGLgKFyGGIePOLicsrDGS_HrTpJuFvbsUgWw_X6ZXKehXoAeVAyPHHXStk2lmG9uzuY33nE1KZQCLDvOH1VKIkbTzKmck2XR3I6_wmONnxXQmAen5uT-Ez0rJCH23wswN1g0uETqzQQugv30VE=w400-h16" width="400" /></a></span></div><div><br /></div></span></span></div></div></span></div></span></div><div><span style="font-family: arial; font-size: medium;"><br /></span></div><div><br /></div></div></div>ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.com9