Saturday, October 26, 2024

ECG Blog #453 — Is this Wellens' Syndrome?


The ECG in Figure-1 was obtained from a middle-aged man who presented with a 2 week history of progressively increasing CP (Chest Pain) with exertion. He had his most severe episode of CP the day before he was seen with this ECG. His CP was much less compared to the day before — but it had not yet completely resolved.
  • An initial Troponin drawn less than 1 hour after the ECG in Figure-1 was recorded was over 10,000.

 


QUESTIONS:

  • Given this history — How would YOU interpret this ECG?
  • Is this Wellens Syndrome?


Figure-1: The initial ECG in today's case. (To improve visualization — I've digitized the original ECG using PMcardio).



MY Thoughts on Today’s CASE:

The rhythm for the ECG in Figure-1 is sinus at ~85/minute. The PR and QRS intervals are normal; the QTc appears to be borderline prolonged (counting the terminal negative part of the T waves in V3,V4). There is no chamber enlargement. 


Regarding Q-R-S-T Wave Changes:

  • Small q waves are seen in each of the inferior leads. The q wave in lead III is a bit wider than usual for a normal septal q wave — so I was uncertain if these inferior q waves might be of clinical significance.
  • That said — there is a definite QS complex in lead V3 (See Figure-2). This QS complex takes on additional significance because there is loss of r wave from lead V2-to-V3. As a result of this QS in V3 — I interpreted the small Q wave in lead V4 as also significant.
  • Small and narrow q waves of uncertain significance are seen in lateral chest leads V5 and V6.
  • R Wave Progression is delayed because of the loss of anterior forces in leads V3 and V4.


Regarding ST-T Wave Changes:
  • There is ST segment straightening with slight ST elevation in lead V2.
  • The ST segment take-off in lead V3 is slightly elevated and coved in shape — with sharp descent into terminal T wave negativity (BLUE arrow in this lead in Figure-2).
  • Similar ST segment straightening with terminal T wave negativity continues in lead V4, and to a lesser extent in lead V5 (Blue arrows in these leads).
  • There is nonspecific ST-T wave flattening in lead V6 — and in the limb leads.

My Impression of ECG #1 given Today's History:
In this middle-aged man with a 2-week history of CP — with his most severe episode the day before ECG #1 was recorded — and with reduced (but not completely resolved) CP at the time this ECG was recorded — this tracing suggests there has been anterior infarction.
  • My "eye" was immediately drawn to the 2 leads within the RED rectangles in Figure-2 — which highlight the QS complex in lead V3 and the Q in V4 that indicate infarction.
  • NOTE: Preservation of the initial positive deflection (that is the r wave) in leads V1,V2 — suggest the septum is still intact.
  • The initial Troponin of >10,000 confirms infarction has occurred — perhaps the day before ECG #1 was recorded, since CP was most severe at that time.
  • The modest amount of residual ST elevation in anterior leads, in association with terminal T wave inversion in leads V3,V4,V5 and greatly reduced CP — suggest there has been some spontaneous reperfusion.

BOTTOM Line:
 Clinical correlation with today's ECG point to LAD (Left Anterior Descending) occlusion, now with reperfusion T waves (in association with the reduction of CP)
  • The above said, this is not Wellens' Syndrome — because a large infarction has already occurred! (See below for full explanation).
  • P.S.: Cardiac cath was performed — and showed a distal LAD "culprit" lesion that was successfully stented. Echo revealed an ejection fraction of 35-40%.


Figure-2: I've labeled the initial ECG in today's case.


What is Wellens’ Syndrome?

When we talk about Wellens’ Syndrome — It is all about timing. As reviewed in ECG Blog #350 — the clinical significance of Wellens' Syndrome — is that its recognition tells you that the patient has a high-grade LAD narrowing with presumably "hot" thrombus having high propensity to propagate and/or totally occlude the LAD at any point in time (including immediately). 


The above said — Wellens' Syndrome remains a misunderstood and often misdiagnosed clinical entity. The following are the KEY clinical and ECG features that establish the diagnosis of WellensSyndrome:

  • There should be a history of prior chest pain that has resolved at the time the defining ECG is obtained.
  • There should be no more than minimal (if any) troponin elevation
  • There are no new infarction Q (or QS) waves. R wave progression should be preserved (so there is not loss of anterior forces).
  • There may be slight (but not marked) ST elevation in one or more of the chest leads.
  • There is a characteristic biphasic T wave, with rapid T wave descent into terminal negativity in one or more of the chest leads (most often in lead V2 and/or V3 and/or V4).

  • CAVEAT: The diagnosis of Wellens' Syndrome should be made with caution (if at all) in a patient with marked LVH and ST-T wave changes of LV "strain". This is because the ECG finding of increased QRS amplitude that occurs in association with abrupt precordial transition from predominantly negative to predominantly positive QRS complexes — may result in an ST-T wave appearance identical to the biphasic T wave with terminal negativity characteristic of Wellens' changes (See ECG Blog #209 and Blog #254 and Blog #309 — for several examples of this "false positive" appearance).

Why Today's ECG does Not represent Wellens' Syndrome:
Appreciation of the pathophysiology of Wellens' Syndrome facilitates understanding why today's case does not qualify. 
  • The characteristic biphasic T wave with rapid T wave descent into terminal T wave negativity — is indication that there has been brief total occlusion of the LAD, which has now spontaneously reperfused. This ECG finding is a "reperfusion T wave". It may look identical to the ST-T wave appearance seen after a STEMI with marked troponin elevation, that has now reperfused (be this reperfusion spontaneous — or by treatment with PCI or thrombolytics).
  • The Chest Pain required for the definition of Wellens' Syndrome occurred at the time of coronary occlusion. The reason the patient is pain-free at the time the defining ECG is done — is that the "culprit" LAD lesion is now open. IF the "culprit" LAD lesion was still occluded — then rather than a warning of impending infarction (which is the purpose of promptly recognizing Wellens' Syndrome) — there would be ongoing acute infarction.
  • The reason there is no more than minimal (if any) troponin elevation with Wellens' Syndrome — is because the duration of coronary occlusion was so brief that no more than minimal myocardial damage resulted. In contrast, if Troponin is significantly elevated — this implies significant myocardial damage has already occurred (which by definition means you are dealing with a completed infarction — and not with the "warning" of an impending large infarction).
  • For this same reason — there should not be new infarction Q (or QS) waves, which would imply completed infarction.
  • The reason there is no more than slight ST elevation — is because Wellens' Syndrome is not a STEMI (ie, it is not an "ST Elevation" MI).
  • The clinical risk posed by Wellens' Syndrome — is that it is proof there has already been acute thrombotic occlusion of the LAD (albeit brief in duration and followed by spontaneous reopening of the vessel). BUT — What has spontaneously occluded and then spontaneously reopened — is at high-risk of another spontaneous reocclusion (with no guarantee that there will again be spontaneous reopening this next time that the vessel occludes).

Regarding Today's CASE: 
Reread the history in today's case (in the opening paragraph above) — and Take another LOOK at the ECG in Figure-2.
  • Loss of r wave from lead V2-to-V3, so as to form the large QS complex in lead V3 (with Q wave also in lead V4) — indicates that significant anterior infarction has already occurred in today's patient, whose CP has not yet completely resolved — and whose initial Troponin value is already markedly increased (at over 10,000). This indicates completed infarction — and does not fit the definition of Wellens' Syndrome.



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Acknowledgment: My appreciation to Josep Serra Tarragon (from Tarragona, Spain) for the case and this tracing.

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Related ECG Blog Posts to Today’s Case: 

  • ECG Blog #205 — Reviews my Systematic Approach to 12-lead ECG Interpretation.
  •  
  • ECG Blog #209 and ECG Blog #254 and ECG Blog #309 — Review cases of marked LVH that result in similar ST-T wave changes as may be seen with Wellens' Syndrome. 
  • ECG Blog #245 — Reviews my approach to the ECG diagnosis of LVH (outlined in Figures-3 and -4, and the subject of Audio Pearl MP-59 in Blog #245).

  • ECG Blog #320 — Reviews acute OMI of the 1st or 2nd Diagonal (presenting as Wellens' Syndrome).

  • ECG Blog #326 — Reviews a case of Wellens' Syndrome that was missed.
  • ECG Blog #350 — another case of Wellens' Syndrome.

  • ECG Blog #337 — for Review of a case illustrating step-by-step clinical correlation between serial ECGs with symptom severity.

  • See the October 15, 2022 post (including My Comment at the bottom of the page) — for review and illustration of the concept of "Precordial Swirl" (due to proximal LAD OMI).



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ADDENDUM (10/26/2024): I excerpted what follows below from My Comment in the August 12, 2022 post in Dr. Smith's ECG Blog).

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The History of Wellens' Syndrome:

It's hard to believe that the original manuscript describing Wellens' Syndrome was published over 40 years ago! I thought it insightful to return to this original manuscript (de Zwaan, Bär & Wellens: Am Heart J 103: 7030-736, 1982):
  • The authors (de Zwaan, Bär & Wellens) — studied 145 consecutive patients (mean age 58 years) admitted for chest pain, thought to be having an impending acute infarction (Patients with LBBB, RBBB, LVH or RVH were excluded). Of this group — 26/145 patients either had or developed within 24 hours after admission, a pattern of abnormal ST-T waves in the anterior chest leads without change in the QRS complex.
  • I've reproduced (and adapted) in Figure-3 — prototypes of the 2 ECG Patterns seen in these 26 patients. Of note — all 26 patients manifested characteristic ST-T wave changes in leads V2 and V3.
  • Most patients also showed characteristic changes in lead V4.
  • Most patients showed some (but less) ST-T wave change in lead V1.
  • In occasional patients — abnormal ST-T waves were also seen as lateral as in leads V5 and/or V6.

  • Half of the 26 patients manifested characteristic ST-T wave changes at the time of admission. The remaining 13/26 patients developed these changes within 24 hours after hospital admission.
  • Serum markers for infarction (ie, CPK, SGOT, SLDH) were either normal or no more than minimally elevated

ECG Patterns of Wellens' Syndrome:
The 2 ECG Patterns observed in the 26 patients with characteristic ST-T wave changes are shown in Figure-3:
  • Pattern A — was much less common in the study group (ie, seen in 4/26 patients). It featured an isoelectric or minimally elevated ST segment takeoff with straight or a coved (ie, "frowny"-configuration) ST segment, followed by a steep T wave descent from its peak until finishing with symmetric terminal T wave inversion.
  • Pattern B — was far more common (ie, seen in 22/26 patients). It featured a coved ST segment, essentially without ST elevation — finishing with symmetric T wave inversion, that was often surprisingly deep.

Figure-3: The 2 ECG Patterns of Wellens' Syndrome — as reported in the original 1982 article (Figure adapted from de Zwaan, Bär & Wellens: Am Heart J 103:730-736, 1982).


ST-T Wave Evolution of Wellens' Syndrome:
I've reproduced (and adapted) in Figure-4 — representative sequential ECGs obtained from one of the patients in the original 1982 manuscript.
  • The patient whose ECGs are shown in Figure-4 — is a 45-year old man who presented with ongoing chest pain for several weeks prior to admission. His initial ECG is shown in Panel A — and was unremarkable, with normal R wave progression. Serum markers were negative for infarction. Medical therapy with a ß-blocker and nitrates relieved all symptoms.
  •  
  • Panel B — was recorded 23 hours after admission when the patient was completely asymptomatic. This 2nd ECG shows characteristic ST-T wave changes similar to those shown for Pattern B in Figure-3 (ie, deep, symmetric T wave inversion in multiple chest leads — with steep T wave descent that is especially marked in lead V3).

  • Not shown in Figure-4 are subsequent ECGs obtained over the next 3 days — that showed a return to the "normal" appearance of this patient's initial ECG (that was shown in Panel A of Figure-4). During this time — this patient remained asymptomatic and was gradually increasing his activity level.

  • Panel C — was recorded ~5 days later, because the patient had a new attack of severe chest pain. As can be seen — there is loss of anterior forces (deep QS in lead V3) with marked anterior ST elevation consistent with an extensive STEMI. Unfortunately — this patient died within 12 hours of obtaining this tracing from cardiogenic shock. Autopsy revealed an extensive anteroseptal MI with complete coronary occlusion from fresh clot at the bifurcation between the LMain and proximal LAD.


Figure-4: Representative sequential ECGs from one of the patients in the original 1982 article. 
— Panel A: The initial ECG on admission to the hospital; 
— Panel B: The repeat ECG done 23 hours after A. The patient had no chest pain over these 23 hours. NOTE: 3 days after B — the ECG appearance of this patient closely resembled that seen in A ( = the initial tracing)
— Panel C: 5 days later — the patient returned with a new attack of severe chest pain. As seen from this tracing (C) — this patient evolved a large anterior STEMI. He died within hours from cardiogenic shock
 (Figure adapted from de Zwaan, Bär & Wellens: Am Heart J 103:730-736, 1982 — See text).

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Relevant Findings from the 1982 Article:
The ECG pattern known as Wellens' Syndrome was described over 40 years ago. Clinical findings derived from the original 1982 manuscript by de Zwaan, Bär & Wellens remain relevant today.
  • One of the 2 ECG Patterns shown in Figure-3, in which there are characteristic anterior chest lead ST-T wave abnormalities — was seen in 18% of 145 patients admitted to the hospital for new or worsening cardiac chest pain.
  • Variations in the appearance of these 2 ECG patterns may be seen among these patients admitted for chest pain. Serial ECGs do not show a change in QRS morphology (ie, no Q waves or QS complexes developed). Serum markers for infarction remained normal, or were no more than minimally elevated.
  • Among the subgroup of these patients in this 1982 manuscript who did not undergo bypass surgery — 75% (12/16 patients) developed an extensive anterior STEMI from proximal LAD occlusion within 1-2 weeks after becoming pain-free.


LESSONS to Be Learned:

At the time the 1982 manuscript was written — the authors were uncertain about the mechanism responsible for the 2 ECG patterns of Wellens' Syndrome.
  • We now know the mechanism. A high percentage of patients seen in the ED for new cardiac chest pain that then resolves — with development shortly thereafter of some form of the ECG patterns shown in Figure-1 — had recent coronary occlusion of the proximal LAD — that then spontaneously reopened.
  • The reason Q waves do not develop on ECG and serum markers for infarction are normal (or at most, no more than minimally elevated) — is that the period of coronary occlusion is very brief. Myocardial injury is minimal (if there is any injury at all).
  • BUT: What spontaneously occludes, and then spontaneously reopens — may continue with this cycle of occlusion — reopening — reocclusion — reopening — until eventually a final disposition is reached (ie, with the "culprit" vessel staying either open or closed).

  • Clinically: We can know whether the "culprit" artery is either open or closed by correlating serial ECGs with the patient's history of chest pain. For example — resolution of chest pain in association with reduction of ST elevation suggests that the "culprit" vessel has spontaneously reopened. And, if this is followed by return of chest pain in association with renewed ST elevation — the "culprit" artery has probably reclosed.
  • The importance of recognizing Wellens' Syndrome — is that it tells us that timely cardiac cath will be essential IF we hope to prevent reclosure. In the de Zwaan, Bär & Wellens study — 75% of these pain-free patients with Wellens' ST-T wave changes went on to develop a large anterior STEMI within the ensuing 1-2 weeks if they were not treated.
  • Thus, the goal of recognizing Wellens' Syndrome — is to intervene before significant myocardial damage occurs (ie, diagnostic criteria for this Syndrome require that anterior Q waves or QS complexes have not developed — and serum markers for infarction are no more than minimally elevated).
  • It is not "Wellens' Syndrome" — IF the patient is having CP (Chest Pain) at the time one of the ECG patterns in Figure-3 are seen. Active CP suggests that the "culprit" artery is still occluded.
  • Exclusions from the 1982 study were patients with LBBB, RBBB, LVH or RVH. While acute proximal LAD occlusion can of course occur in patients with conduction defects or chamber enlargement — Recognition of the patterns for Wellens' Syndrome is far more challenging when any of these ECG findings are present.
  • Finally, a word about the 2 ECG Patterns in Figure-3. As suggested from data in the original 1982 manuscript, Pattern A — is far less common, but more specific for Wellens' Syndrome IF associated with the "right" history (ie, prior chest pain — that has now resolved at the time ST-T wave abnormalities appear).
  • Unlike the example in Figure-3 — Pattern B may be limited to symmetric T wave inversion without the finding of steep T wave descent into terminal negativity in any lead. Deep, symmetric T wave inversion per se is seen in a number of other conditions, and is much less specific for Wellens' Syndrome.

In Conclusion: The 145 patients studied by de Zwaan, Bär & Wellens in 1982 continue to this day to provide clinical insight into the nature of Wellens' Syndrome.


 







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