A Case Study
Loosely based on Wellens’ syndrome, a case report in Annals of Emergency Medicine, March 1999 (citation below).
History of Present Illness
A 45 y/o white man with a history of HTN, DM presents to the ED complaining of sharp, left sided chest pain for 2 weeks. His pain usually occurs with some sort of exertion, but this morning it occurred at rest. He describes it as a crushing pain and notes it feels like someone is sitting on his chest. He reports being seen at an outside hospital two weeks ago and having a negative workup including EKG and cardiac enzymes and was discharged with follow up as an outpatient.
Currently, he is pain free and completely stable. His initial troponin is negative. His EKG is read by the computer as having nonspecific T-Wave changes. It shows no ST elevations, no Q waves, and a normal R wave progression. There are some T-wave inversions in V2 and V3 that have an odd, biphasic appearance (initially positive with a terminal negative deflection), which unfortunately the resident does not recognize. The patient is sent for an exercise stress test for workup of possible unstable angina.
After 2 minutes on the treadmill, he develops ST elevations across the precordial leads. Shortly thereafter he progresses to ventricular tachycardia and despite aggressive ACLS treatment, he dies within an hour. His autopsy later reveals 95% stenosis of the proximal LAD. How could this terrible outcome have been prevented?
ACS broadly can be subdivided into STEMI (30%), NSTEMI (25%), and unstable angina (38%). STEMI and NSTEMI are both categories of myocardial infarction differentiated by EKG pattern and pathophysiology; both present with elevations in cardiac enzymes, indicating death of cardiac tissue. Unstable angina is often a warning sign, indicating new plaque instability. As opposed to stable angina, unstable angina occurs suddenly, at rest or with minimal exertion (or at lesser degrees of exertion than the individual's previous angina--"crescendo angina"). New onset angina is also considered unstable angina, since it suggests a new problem in a coronary artery. Wellens’ syndrome is a subtle subcategory of unstable angina characterized by specific EKG changes that represent significant proximal LAD stenosis that will often progress to an anterior wall MI if untreated.
T-Wave Abnormalities c/w Wellens’ Syndrome in V2-3 (may extend to V1-6)
- Type A = Biphasic, with initial positivity & terminal negativity (24% of cases)
- Type B = Deeply and symmetrically inverted (76% of cases)
- Recent history of angina (but Wellens ECG pattern is almost always present in pain-free state)
- Normal (or minimal elevation of) serum cardiac markers
- Isoelectric or minimally-elevated ST segment (< 1mm)
- No precordial Q waves
- Preserved precordial R wave progression
Classic EKG Findings
This syndrome was first reported in 1982. In the original study, this characteristic EKG pattern was identified in 26 of 145 consecutive patients admitted with unstable angina (18%). H. J. J. Wellens and his group noticed that among the 16 patients with the syndrome who did not undergo revascularization, 12 (75%) went on to suffer a massive anterior wall MI, often within several days, despite relief of symptoms with medical management. This piqued their interest and in a follow-up prospective study with 1260 unstable angina patients, 180 (14%) again had this unique EKG pattern. This time, all 180 were urgently taken to the cath lab. Every single one had a greater than 50% stenosis of the proximal LAD (mean stenosis of 85%).
The T Wave Changes
First you have sudden occlusion of the LAD, which can cause a transient anterior STEMI. At this point, the patient would have angina chest pain, diaphoresis, and other classic symptoms. However, as this often occurs in the prehospital setting, it may not be captured on EKG. In cases of Wellens’ Syndrome (unlike a traditional STEMI), you have re-perfusion of the LAD (due to spontaneous clot lysis or prehospital aspirin administration). The chest pain resolves, ST elevation improves, and T waves become biphasic or inverted (The classic Wellens pattern). Of note, this T wave morphology is identical to patients who re-perfuse after a successful PCI of the proximal LAD.The key point her however is that coronary perfusion is unstable. Thus, the LAD can re-occlude at any time. If this happens, the first sign on the ECG is an apparent normalization of the T waves — “pseudo-normalization”. The T waves switch from biphasic/inverted to upright and prominent. This is a sign of hyperacute STEMI and is usually accompanied by recurrence of chest pain, although the ECG changes can precede the symptoms.If the artery remains occluded, the patient now develops an evolving anterior STEMI (as was the case with many of the patients in Wellens’ initial study). Alternatively, a “stuttering” pattern may develop, with intermittent re-perfusion and re-occlusion. This would manifest as alternating ECGs demonstrating Wellens’ and pseudonormalisation/STEMI patterns.
*The content in this section was adapted from Life in the Fast Lane, a FOAM blog with a great overview of Wellen’s syndrome complete with sample EKG’s. The content is available here.
Unlike most other cases of angina, patients who present with a history of chest pain and an EKG that demonstrates Wellens changes should NEVER be sent for a stress test. This is painfully evident in the case presented above. Instead, due to the critical LAD stenosis, these patients usually require invasive therapy as soon as possible. They do poorly with medical management (as was evidenced in Wellens’ initial study. Thus, it is extremely important that all ED physicians are able to quickly recognize these characteristic EKG changes. This is not a rare phenomenon (up to 20% of all unstable angina patients will have this pattern), and it is extremely specific (180 out of 180 patients with these EKG changes in the initial follow up prospective study wound up having at least a 50% proximal LAD stenosis).
For Further Reflection
- Here is a good set of serial EKG’s by Dr. Steven Smith showing the stuttering pattern of Wellens' biphasic TWI (re-perfusion) followed by pseudonormalization (re-occlusion of the LAD).
- This is a great, concise review of a lot of the classic cardiology eponyms coupled with pathology, clinical significance, and an example EKG:
Parikh KS, Agarwal R, Mehrotra AK, Swamy RS. Wellens’ Syndrome: A Life-Saving Diagnosis. American Journal of Emergency Medicine. 2012 Jan;30(1):255.e3-5. doi: 10.1016/j.ajem.2010.10.014. Epub 2010 Nov 23.
Rhinehardt J, Brady W, Perron A, Mattu A: Electrocardiographic Manifestations of Wellens’ Syndrome. American Journal of Emergency Medicine. Nov 2002; 20(7):638-43. 12442245
Tandy TK, Bottomy DP, Lewis JG: Wellens’ syndrome. Annals of Emergency Medicine. March 1999;33:347-351. 10036351