tag:blogger.com,1999:blog-3364570834099131201.post8142748022299413846..comments2024-03-23T08:57:50.965-04:00Comments on ECG Interpretation: ECG Blog #144 — An Alternating BBB?ECG Interpretationhttp://www.blogger.com/profile/02309020028961384995noreply@blogger.comBlogger14125tag:blogger.com,1999:blog-3364570834099131201.post-83104226659476597102019-01-09T01:49:09.816-05:002019-01-09T01:49:09.816-05:00This was really helpful and gave me far more ideas...This was really helpful and gave me far more ideas.<br />David millarhttps://www.clippingsolutions.comnoreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-60036992488067841202017-12-09T22:52:04.324-05:002017-12-09T22:52:04.324-05:00Thank you sir!Thank you sir!Nguyen Chí Tínhhttps://www.blogger.com/profile/10755092672681857950noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-12094558077219175722017-12-09T06:24:14.216-05:002017-12-09T06:24:14.216-05:00The reason I don't think beats #2,4,6 are vent...The reason I don't think beats #2,4,6 are ventricular escapes — is the very typical QRS morphology for RBBB conduction not only for beat #4 (in lead V1) — but also for beat #6 (in V6). Marriott made the point that RBBB conduction is virtually assured when you have the reciprocal of an rSR' in V6 (ie, narrow q- taller slender R- and wide terminal S wave). You are unlikely to see this with ventricular escape ... ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-25002357538767191752017-12-09T06:08:02.801-05:002017-12-09T06:08:02.801-05:00Thanks Mario — a true compliment coming from you! ...Thanks Mario — a true compliment coming from you! Be sure to check out the "P.S." that I just added yesterday at the bottom of this blog piece — which makes it even MORE complicated ... (but perhaps more "fun" — :) Grazie ancora per il tuo sostegno!ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-44151649708437924332017-12-09T05:00:03.170-05:002017-12-09T05:00:03.170-05:00@ M G — As described in the blog, you are correct ...@ M G — As described in the blog, you are correct that the difference in QRS morphology for beats #2,4,6 is not because of "aberrant conduction" (because there no reason to change from LBBB to RBBB conduction). Instead, I believe this is a manifestation of the uncommon phenomenon of "alternating BBB" (ie, one beat conducts with LBBB, and the next with RBBB) — and that is generally an indication of severe underlying conduction system disease in this patient who also has significant 2nd-degree AV block — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-4639730165439709602017-12-09T04:51:50.099-05:002017-12-09T04:51:50.099-05:00I think the QRS morphology which changes for the b...I think the QRS morphology which changes for the beats 2,4,6 probably supports they are not arising like other sinus beats and no apparent reason for those beats to conduct with abberancy.. Dr.Ken.. Can you agree to this? Thanks in advance.. MGhttps://www.blogger.com/profile/06233522417024317416noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-50188253657300256312017-12-08T11:14:10.588-05:002017-12-08T11:14:10.588-05:00I thank you, Sir for offering us students such a w...I thank you, Sir for offering us students such a wonderful website !Majuranhttps://www.blogger.com/profile/03833908443216737825noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-8480594785419014082017-12-08T07:01:17.510-05:002017-12-08T07:01:17.510-05:00Hi — The more I think about your question, the mor...Hi — The more I think about your question, the more I cannot rule this out without additional monitoring. As a result, I added a "P.S." at the bottom of the blog to include the possibility that you raise! Thanks again for your comment — :)ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-8427287076502552982017-12-06T11:06:44.360-05:002017-12-06T11:06:44.360-05:00Devilishly complicated tracing but a great learnin...Devilishly complicated tracing but a great learning! Thank you so much!Mario Parrinellohttps://www.blogger.com/profile/07136945770330333718noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-76318184421131875512017-12-06T10:56:49.246-05:002017-12-06T10:56:49.246-05:00Thanks for your very interesting writing , sir! Al...Thanks for your very interesting writing , sir! Althought I also think beats# 2,4,6 are junctional escape beats with RBBB conduction because of their very typical morphology for RBBB. But I also wonder if there is possibility that they are ventricular escape beats sir. How do we distinguish between them sir?Nguyen Chí Tínhhttps://www.blogger.com/profile/10755092672681857950noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-86091551305304920632017-12-06T05:58:35.848-05:002017-12-06T05:58:35.848-05:00Thank you very much for your explanation !Thank you very much for your explanation !Majuranhttps://www.blogger.com/profile/03833908443216737825noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-41007382928075529742017-12-05T17:47:44.610-05:002017-12-05T17:47:44.610-05:00You have made a NICE observation! The reason why I...You have made a NICE observation! The reason why I do not think the P waves labeled b, e and h are conducting — is that the “increment” in PR interval (ie, the difference between the PR interval before beats #1, 3, 5 that we know are conducting — and the PR interval that we would then have if b, e and h were conducting) is VERY large. It is much more than one would expect with an AV Wenckebach block. It seems far more logical that the mechanism here is “escape-capture”, with beats #2,4,6 being junctional escapes — and with b, e and h just not conducting. To complicate things further — at times there can be “dual AV nodal physiology” with both a faster and slower AV nodal pathway — in which case on occasion one can get large jumps in the PR interval increment (though even then, they are usually not this large). Bottom Line — We really need more monitoring to get a better idea of what is happening. In the meantime, I submit that this is probably “escape-capture” rather than Mobitz I with huge PR interval increment. Thanks for your comment.ECG Interpretationhttps://www.blogger.com/profile/02309020028961384995noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-68399895337262753902017-12-05T08:17:56.356-05:002017-12-05T08:17:56.356-05:00Thanks for this interesting case.
As for a beginn...Thanks for this interesting case.<br /><br />As for a beginner like me it looks like as if the pr interval beginning from the p- waves b,e,h looks quite similar. And thus one might think that these p-waves are conducting the beats 2, 4 and 6. Could you explain us why this thought is wrong ? Majuranhttps://www.blogger.com/profile/03833908443216737825noreply@blogger.comtag:blogger.com,1999:blog-3364570834099131201.post-36091136592055552202017-12-05T00:40:13.040-05:002017-12-05T00:40:13.040-05:00Very interesting and helpful..thanksVery interesting and helpful..thanksAnonymoushttps://www.blogger.com/profile/16767325259329028209noreply@blogger.com