What is Wellens syndrome?

Wellens Syndrome: A Critical Cardiac Warning Sign

Wellens syndrome is a specific electrocardiographic pattern that indicates critical stenosis of the proximal left anterior descending (LAD) coronary artery, requiring urgent cardiac catheterization to prevent anterior wall myocardial infarction.

Definition and Diagnostic Criteria

Wellens syndrome is characterized by:

• Specific T-wave changes in precordial leads (especially V2-V3) during pain-free periods
• History of anginal chest pain (though some cases may be asymptomatic 1)
• Little or no cardiac enzyme elevation
• Minimal or no ST-segment elevation
• Preservation of precordial R waves
• Absence of pathological Q waves

ECG Patterns

There are two distinct ECG patterns:

1. Type A (initial pattern): Biphasic T waves with initial positivity and terminal negativity in leads V2-V3
2. Type B (evolved pattern): Deep, symmetrically inverted T waves in leads V2-V4

Evidence suggests that Wellens syndrome can evolve from pattern A to pattern B 2, representing progressive ischemic changes in the myocardium.

Clinical Significance

The American Heart Association identifies Wellens syndrome as a high-risk ECG finding that indicates critical LAD stenosis 3. This is particularly important because:

• It represents a pre-infarction stage of coronary artery disease
• Without intervention, it frequently progresses to extensive anterior wall myocardial infarction
• The ECG changes are often most prominent during pain-free periods, making them easy to miss
• Deep symmetrical T-wave inversion across precordial leads indicates a critical stenosis of the LAD (Wellens' phenomenon) 3

Management

The definitive treatment for Wellens syndrome is urgent cardiac catheterization with revascularization:

• Serial ECGs are crucial for early detection, especially in cases with initially subtle changes 2
• Stress testing is contraindicated as it may precipitate complete LAD occlusion and extensive anterior MI
• Medical therapy alone is insufficient in most cases, though rare variants caused by coronary artery spasm may respond to calcium channel blockers and nitrates 4

Important Considerations

• Wellens syndrome can occasionally present without chest pain 1, making ECG recognition even more critical
• Failure to identify these characteristic ECG patterns can lead to devastating outcomes including myocardial infarction or death 5
• The syndrome represents a narrow window of opportunity for intervention before complete occlusion occurs
• Emergency physicians should maintain a high index of suspicion, especially in patients with risk factors for coronary artery disease

Pitfalls to Avoid

• Discharging patients with resolved chest pain but persistent Wellens ECG pattern
• Misinterpreting the T-wave changes as non-specific or due to other causes
• Delaying cardiac catheterization in favor of non-invasive testing
• Failing to obtain serial ECGs in patients with suspicious T-wave changes
• Missing the diagnosis in asymptomatic patients who may still have critical LAD stenosis

Early recognition of Wellens syndrome and prompt referral for cardiac catheterization are essential to prevent progression to extensive anterior wall myocardial infarction and its associated morbidity and mortality.