Wellens Syndrome: A Critical ECG Pattern
Wellens syndrome is a specific ECG pattern characterized by deeply inverted or biphasic T waves in the precordial leads (particularly V2-V3) that indicates critical stenosis of the proximal left anterior descending coronary artery (LAD) and represents a pre-infarction state requiring urgent intervention. 1, 2
Diagnostic Criteria
Wellens syndrome consists of two distinct ECG patterns 3, 4:
- Type A: Biphasic T waves in leads V2-V3 (and sometimes V4)
- Type B: Deep, symmetrically inverted T waves in leads V2-V3 (and sometimes V1-V4)
Additional diagnostic criteria include 4:
- History of anginal chest pain (though pain may be absent at time of ECG)
- Little or no cardiac enzyme elevation
- Little or no ST-segment elevation
- No loss of precordial R waves
- No pathologic precordial Q waves
Clinical Significance
Wellens syndrome represents a critical pre-infarction state that can progress to extensive anterior wall myocardial infarction if left untreated 3, 5
The ECG changes reflect severe stenosis of the proximal LAD coronary artery in most cases, though mid-LAD or even circumflex artery stenosis has been reported in some cases 3, 6
These T-wave changes often persist even after chest pain has resolved, making them an important finding during pain-free intervals 7, 4
The American Heart Association recognizes Wellens syndrome as a high-risk pattern requiring urgent evaluation 2
Clinical Presentation
Most patients present with symptoms consistent with acute coronary syndrome, particularly angina 5, 4
However, some patients may present with atypical symptoms such as epigastric pain or even be completely asymptomatic 6, 7
The ECG changes may be the only indication of critical coronary stenosis in asymptomatic patients 7
Management
Patients with Wellens syndrome should be considered high-risk and require urgent cardiac catheterization 2, 5
Conservative medical management alone is insufficient, as these patients are at high risk for developing extensive anterior wall myocardial infarction 3, 4
Initial management should include 2:
- ECG monitoring for life-threatening arrhythmias
- Aspirin administration (162-325 mg) if no contraindications
- Consideration of nitroglycerin for symptom relief if present
Primary percutaneous coronary intervention (PCI) should be implemented within 120 minutes of first medical contact 2
Pitfalls to Avoid
Failing to recognize the characteristic ECG pattern, especially when patients are pain-free at the time of ECG 7, 4
Discharging patients with resolved chest pain but persistent Wellens ECG pattern 3, 5
Performing stress testing, which can precipitate complete LAD occlusion and extensive anterior wall infarction 4
Confusing Wellens pattern with other causes of T-wave inversion such as cerebrovascular accidents, cardiomyopathy, or other non-ischemic causes 1
Special Considerations
Even asymptomatic patients with Wellens ECG pattern should undergo coronary angiography due to the high risk of severe LAD stenosis 7
Serial ECGs should be performed if the initial ECG is equivocal or does not show evidence to support clinical suspicion of myocardial ischemia 2
Additional ECG leads (V7-V9) may help identify patients with posterior wall involvement 2