What is Wellens syndrome (Left Anterior Descending coronary artery syndrome) on an electrocardiogram (ECG) and how is it managed in patients with symptoms suggestive of acute coronary syndrome?

Wellens Syndrome: ECG Recognition and Urgent Management

Wellens syndrome is a specific ECG pattern indicating critical proximal left anterior descending (LAD) artery stenosis that represents a pre-infarction state requiring urgent coronary angiography and revascularization to prevent extensive anterior myocardial infarction. 1, 2

ECG Characteristics

Wellens syndrome presents with two distinct patterns in the anterior precordial leads (V2-V4):

• Type A (25% of cases): Biphasic T waves with initial positivity followed by negativity 3, 4, 5
• Type B (75% of cases): Deep, symmetrical T-wave inversions (≥2 mm) 1, 2, 5

Key Diagnostic Criteria

The syndrome requires ALL of the following features 2:

• History of recent anginal chest pain (typically resolved at time of ECG)
• T-wave abnormalities in precordial leads V2-V4 (or V2-V3)
• Normal or minimally elevated cardiac biomarkers
• Preserved precordial R-wave progression
• Absence of significant ST-segment elevation (<1 mm)
• Absence of pathological Q waves

Critical Recognition Points

• The ECG changes typically appear during a pain-free period after resolution of chest discomfort 2, 4
• T-wave abnormalities are persistent and may remain for hours to weeks 2
• These changes represent ongoing myocardial ischemia despite symptom resolution 1, 6

Clinical Significance and Natural History

Without intervention, 75% of patients with Wellens syndrome progress to extensive anterior wall myocardial infarction within weeks. 6, 2 The pattern indicates critical stenosis (typically >70%) of the proximal LAD, placing a large territory of myocardium at risk 3, 2.

Immediate Management Algorithm

Step 1: Recognition and Risk Stratification

• Obtain 12-lead ECG within 10 minutes of first medical contact 7
• Treat as high-risk NSTE-ACS requiring urgent evaluation 1, 8
• Initiate continuous cardiac monitoring immediately to detect life-threatening arrhythmias 1

Step 2: Initial Medical Therapy

Start baseline ACS treatment immediately 8:

• Aspirin 162-325 mg (or 75-150 mg per ESC) if no contraindications 1, 8, 9
• Anticoagulation with low-molecular-weight heparin or unfractionated heparin 8, 9
• Beta-blockers unless contraindicated 8, 9
• Nitroglycerin (oral or IV) for symptom relief if chest pain present 1, 8, 9

Step 3: Serial Biomarker Monitoring

• Obtain cardiac troponin immediately and repeat at 6-12 hour intervals 8, 9
• Do not rely on a single normal troponin to exclude ACS - serial measurements are mandatory 8
• Note that Wellens syndrome typically presents with normal or minimally elevated biomarkers initially 2

Step 4: Definitive Management

Urgent coronary angiography with percutaneous coronary intervention (PCI) is the definitive treatment 1, 6, 5:

• Primary PCI should be performed within 120 minutes of first medical contact 1
• For marked symmetrical T-wave inversion ≥2 mm in precordial leads with ST-depression >1 mm in ≥6 leads, proceed to immediate invasive strategy (<2 hours) 8
• Radial access is preferred over femoral access to reduce bleeding and vascular complications 1

Step 5: Post-Intervention Care

• Standard dual antiplatelet therapy (aspirin plus P2Y12 inhibitor for 12 months) 1, 9
• High-intensity statin therapy 9
• ACE inhibitors if LVEF <40%, diabetes, hypertension, or chronic kidney disease present 9

Critical Pitfalls to Avoid

Do NOT Perform Exercise Stress Testing

Exercise stress testing is contraindicated in Wellens syndrome - it can precipitate extensive anterior MI 3. One case report documented anterior ST-elevation at 2 minutes of exercise testing in a patient with Wellens pattern 3.

Do NOT Dismiss as Benign T-Wave Changes

• Non-specific T-wave changes carry a twofold increased risk of coronary events compared to normal ECGs 8
• The persistent nature of T-wave abnormalities in Wellens syndrome distinguishes it from transient ischemic changes 2

Do NOT Delay Intervention

• Failure to recognize Wellens syndrome and proceed urgently to catheterization leads to devastating outcomes including extensive MI and death 6, 5
• Medical management alone is insufficient - definitive revascularization is required 2, 5

Consider Important Differentials

While managing as high-risk ACS, be aware of mimics 1:

• Hypertrophic cardiomyopathy
• Takotsubo cardiomyopathy
• Cerebrovascular accidents (can cause deep T-wave inversions)
• Pericarditis

Special Considerations

Atypical Presentations

Wellens syndrome can present with atypical symptoms 6:

• Epigastric pain mimicking gastrointestinal pathology
• Syncope
• Isolated dyspnea without chest pain

Anatomical Variations

• While classically associated with proximal LAD stenosis, rare cases involve significant circumflex artery occlusion with Wellens-like ECG pattern 6
• Consider additional ECG leads (V7-V9) if posterior wall involvement suspected 1

Recurrence Risk

Wellens syndrome can recur in patients with previous LAD stenting, indicating in-stent restenosis requiring repeat intervention 4.