What is Wellens type B?

Wellens Syndrome Type B

Wellens syndrome type B is characterized by deep, symmetrical T-wave inversions in the precordial leads (V1-V4), indicating critical stenosis of the proximal left anterior descending (LAD) coronary artery that requires urgent cardiac catheterization to prevent extensive anterior myocardial infarction. 1

ECG Patterns of Wellens Syndrome

Wellens syndrome has two distinct ECG patterns:

1. Type A (25% of cases): Biphasic T waves with initial positivity and terminal negativity in leads V2-V3
2. Type B (75% of cases): Deep, symmetrical T-wave inversions in leads V1-V4 1, 2

These ECG changes are most prominent during pain-free periods, making them easy to miss during active chest pain episodes 1. The ECG typically shows:

• Deep, symmetrical T-wave inversions (type B) or biphasic T waves (type A)
• Minimal or no ST-segment elevation
• Preservation of precordial R waves
• Absence of pathological Q waves
• Normal or minimally elevated cardiac enzymes 2, 3

Clinical Significance

Wellens syndrome represents a pre-infarction stage of coronary artery disease 1. The characteristic T-wave changes correlate with a critical stenosis in the proximal LAD, which without intervention, frequently progresses to extensive anterior wall myocardial infarction 4.

Key clinical features include:

• History of anginal chest pain (though some cases may be asymptomatic) 2
• Little or no cardiac enzyme elevation
• ECG changes often most prominent during pain-free periods 1, 5

Diagnostic Approach

When Wellens syndrome is suspected:

1. Review ECG for characteristic T-wave changes in precordial leads
2. Assess cardiac biomarkers (typically normal or minimally elevated)
3. Obtain history of recent anginal episodes
4. Avoid stress testing as it is contraindicated and may precipitate complete LAD occlusion 1

Management

The definitive treatment for Wellens syndrome is:

• Urgent cardiac catheterization with revascularization 1, 3
• Medical therapy alone is insufficient in most cases
• Percutaneous coronary intervention (PCI) is typically required for the critical LAD stenosis

Clinical Pitfalls to Avoid

1. Missing the diagnosis during pain-free periods when patients may appear stable
2. Ordering stress testing, which is contraindicated and may precipitate complete LAD occlusion and extensive anterior MI 1
3. Discharging patients with these ECG findings without cardiac catheterization
4. Delaying intervention, as these patients are at high risk for progression to extensive anterior wall MI 3

Early recognition of these characteristic ECG patterns and prompt referral for cardiac catheterization are essential to prevent devastating outcomes including myocardial infarction or death 1, 3.