Wellens Syndrome

A 50-year-old man presents to the emergency department after an episode of exertional chest pain that occurred approximately 1 hour earlier and has now completely resolved. He has a history of hypertension and is taking amlodipine. Vital signs show a blood pressure of 130/80 mmHg, pulse rate of 88 beats/min, respiratory rate of 18 breaths/min, oxygen saturation of 98% on room air, and temperature of 96.9°F. At the time of evaluation, the patient is pain-free. Electrocardiography demonstrates biphasic T waves with initial positivity followed by terminal negativity in leads V2 through V3, with preserved precordial R-wave progression, no pathologic Q waves, and no significant ST-segment elevation. Initial high-sensitivity cardiac troponin is below the sex-specific 99th percentile upper reference limit. Serial troponin testing shows no significant rise or fall. Diagnosis?

The diagnosis is a biphasic Wellens pattern, commonly termed type A Wellens syndrome in contemporary usage.

The combination of recent anginal chest pain, a pain-free state during ECG acquisition, biphasic T waves with terminal negativity in V2 through V3, preserved R-wave progression, absence of pathologic Q waves, little or no ST-segment elevation, and normal serial cardiac troponin measurements is highly characteristic of the Wellens pattern.

Because type A and type B terminology has occasionally been used inconsistently in the literature, the actual T-wave morphology should always be explicitly described.

1. Definition

Wellens syndrome is a high-risk clinical and electrocardiographic syndrome characterized by specific anterior precordial T-wave abnormalities that most characteristically occur during a pain-free interval after recent anginal symptoms.

The pattern is classically associated with severe left anterior descending coronary artery disease, historically most often involving the proximal LAD.

Wellens syndrome is a high-risk acute coronary syndrome pattern that classically occurs without diagnostic ST-segment elevation but may signal severe LAD disease or acute coronary occlusion followed by reperfusion.

In a patient such as this one, with persistently normal high-sensitivity cardiac troponin measurements, the clinical syndrome lies on the unstable-angina end of the acute coronary syndrome spectrum, but the ECG remains a high-risk finding requiring urgent coronary evaluation.

Although the classic association is with proximal LAD stenosis, the ECG pattern itself does not establish the exact coronary anatomy. Coronary angiography is required to define the culprit lesion and the extent of coronary disease.

2. ECG Patterns

Two characteristic Wellens T-wave morphologies are commonly described.

2.1 Biphasic Wellens Pattern

This morphology is commonly termed type A in contemporary usage.

It is characterized by:

1.      Biphasic T waves

2.      Initial positive deflection followed by terminal negative deflection

3.      Greatest prominence in V2 through V3

4.      Possible extension into additional anterior precordial leads

This is the morphology demonstrated in this patient.

2.2 Deeply Inverted Wellens Pattern

This morphology is commonly termed type B in contemporary usage.

It is characterized by:

1.      Deep T-wave inversion

2.      Symmetric T-wave inversion

3.      Greatest prominence in V2 through V3

4.      Possible extension across additional anterior precordial leads

The deeply inverted pattern is more frequently reported than the biphasic pattern.

Because type A and type B labels have been used inconsistently in some publications, the ECG morphology should always be stated explicitly rather than relying on the letter designation alone.

3. Characteristic Diagnostic Features

The characteristic Wellens pattern includes:

1.      Recent history of anginal chest pain

2.      Patient often pain-free when the characteristic ECG is recorded

3.      Biphasic or deeply inverted T waves, especially in V2 through V3

4.      T-wave abnormalities that may extend across V1 through V6

5.      Minimal or no ST-segment elevation, typically less than 1 mm

6.      Preserved precordial R-wave progression

7.      Absence of pathologic precordial Q waves

8.      Cardiac troponin that may be:

o    Normal

o    Minimally elevated

o    Elevated if acute myocardial injury has occurred

Normal cardiac troponin does not make the Wellens pattern benign.

4. Pathophysiology

The characteristic Wellens ECG pattern is thought to reflect transient LAD ischemia followed by spontaneous reperfusion.

A simplified sequence is:

1.      A severe LAD lesion produces transient myocardial ischemia.

2.      Coronary blood flow becomes critically reduced or transiently interrupted.

3.      Spontaneous reperfusion occurs.

4.      The patient's chest pain resolves.

5.      Reperfusion-related repolarization abnormalities produce the characteristic anterior T-wave pattern.

6.      Recurrent coronary occlusion may subsequently occur if the underlying lesion is not treated.

This explains why the characteristic T-wave abnormalities are often recorded after chest pain has resolved rather than during active pain.

During recurrent ischemia, the T waves may transiently normalize, become upright and hyperacute, or evolve into other ischemic ECG abnormalities.

5. Clinical Features

5.1 Typical Presentation

Patients usually have:

1.      Recent episodes of anginal chest pain

2.      Chest pressure or tightness with exertion or at rest

3.      Radiation to the arm, neck, jaw, or shoulder in some patients

4.      Associated dyspnea, diaphoresis, nausea, or other ischemic symptoms

5.      Resolution of pain before the characteristic ECG is obtained

At the time the Wellens pattern is recognized, the patient may appear clinically stable.

5.2 Important Clinical Principle

The absence of active chest pain does not indicate that the underlying coronary risk has resolved.

The characteristic ECG may represent evidence of severe coronary disease or transient coronary occlusion with reperfusion despite temporary symptom resolution.

6. Diagnosis

Wellens syndrome is recognized through the combination of:

1.      Compatible recent ischemic symptoms

2.      Characteristic ECG morphology

3.      Appropriate serial cardiac biomarker testing

4.      Exclusion of important alternative causes of the T-wave abnormalities

5.      Definition of coronary anatomy by invasive angiography

6.1 Electrocardiography

The characteristic ECG morphologies are:

Biphasic pattern

·         Initial positive T-wave component followed by terminal negativity in V2 through V3

Deeply inverted pattern

·         Deep, symmetric T-wave inversion in V2 through V3, often extending across additional anterior leads

Additional supportive features include:

1.      Little or no ST-segment elevation

2.      No pathologic precordial Q waves

3.      Preserved R-wave progression

Serial ECGs are important because the pattern may evolve dynamically.

The 2026 Fifth Universal Definition of Myocardial Infarction recognizes biphasic or deeply inverted T waves in V2 through V3 during pain-free intervals as a Wellens pattern and includes this among ECG patterns that may suggest acute coronary occlusion.

6.2 High-Sensitivity Cardiac Troponin

High-sensitivity cardiac troponin should be measured serially according to an appropriate ACS diagnostic pathway.

Troponin may initially be normal in Wellens syndrome.

A single negative troponin, particularly soon after symptom onset, does not exclude myocardial infarction and does not eliminate the need for urgent evaluation.

If serial troponin testing demonstrates a rise and/or fall with at least one value above the sex-specific 99th percentile upper reference limit, together with clinical evidence of myocardial ischemia, the patient meets criteria for myocardial infarction.

In this patient, serial troponin concentrations remain below the sex-specific 99th percentile upper reference limit without a significant rise or fall, supporting the absence of acute myocardial injury.

6.3 Coronary Angiography

Invasive coronary angiography is the definitive investigation for defining coronary anatomy.

The classic Wellens pattern is strongly associated with severe LAD coronary disease, particularly proximal LAD disease in the original descriptions.

However, the precise location and severity of coronary disease cannot be determined from the ECG alone.

Angiography determines:

1.      Presence and severity of LAD disease

2.      Exact lesion location

3.      Presence of acute coronary occlusion or severe stenosis

4.      Presence of multivessel coronary disease

5.      Suitability for PCI

6.      Whether CABG may be more appropriate

Urgent invasive coronary angiography should be arranged, with timing individualized according to ongoing symptoms and hemodynamic or electrical stability.

A patient with recurrent ischemic pain, hemodynamic instability, life-threatening arrhythmia, or other very high-risk features requires more immediate invasive evaluation.

7. Differential Diagnosis

Anterior T-wave inversion or biphasic T waves are not completely specific to Wellens syndrome.

Important alternatives include:

1.      Evolving anterior myocardial infarction or other acute ischemic ECG patterns

2.      Left ventricular hypertrophy with repolarization abnormalities

3.      Bundle branch block

4.      Pulmonary embolism

5.      Takotsubo syndrome

6.      Myocarditis

7.      Central nervous system injury

8.      Electrolyte abnormalities

9.      Drug-associated coronary vasospasm

10.  Other causes of myocardial ischemia

A patient may have a Wellens ECG pattern and simultaneously meet criteria for myocardial infarction if acute myocardial injury is demonstrated.

A Wellens-like ECG pattern caused by a condition other than severe LAD atherosclerotic disease is sometimes termed pseudo-Wellens syndrome.

The ECG must therefore be interpreted together with symptoms, biomarkers, imaging, and coronary anatomy.

8. Management

Wellens syndrome should be treated as a high-risk acute coronary syndrome.

8.1 Immediate Measures

Management includes:

1.      Continuous cardiac monitoring

2.      Intravenous access

3.      Serial 12-lead ECGs

4.      Serial high-sensitivity cardiac troponin measurements

5.      Assessment of ischemic and bleeding risk

6.      Early cardiology consultation

8.2 Aspirin

Aspirin should be administered promptly unless contraindicated.

A loading dose of 162 to 325 mg orally, preferably chewed when feasible, is appropriate.

Maintenance aspirin therapy is then continued according to the overall antithrombotic strategy.

8.3 P2Y12 Inhibitor Therapy

Additional P2Y12 inhibitor therapy should follow contemporary ACS recommendations and the planned invasive strategy.

When PCI is anticipated within approximately 24 hours, P2Y12 administration can be deferred until coronary anatomy is defined.

If angiography is expected to be substantially delayed, upstream P2Y12 therapy may be considered after balancing ischemic and bleeding risks.

Choice of agent depends on:

1.      Planned PCI

2.      Bleeding risk

3.      Previous stroke or transient ischemic attack

4.      Drug contraindications

5.      Other patient-specific factors

8.4 Anticoagulation

Parenteral anticoagulation is recommended as part of ACS management.

Because urgent invasive evaluation is anticipated in this patient, unfractionated heparin is an appropriate choice when an early invasive strategy is planned.

Other anticoagulants may be appropriate in selected NSTE-ACS patients according to the planned invasive strategy, renal function, and bleeding risk.

Fondaparinux should not be used as the sole anticoagulant during PCI because of the risk of catheter thrombosis.

8.5 Lipid-Lowering Therapy

High-intensity statin therapy should be initiated unless contraindicated.

Examples include:

1.      Atorvastatin 40 to 80 mg daily

2.      Rosuvastatin 20 to 40 mg daily

Additional lipid-lowering therapy should be used when necessary to achieve contemporary secondary-prevention lipid targets.

8.6 Anti-Ischemic Therapy

Nitroglycerin may be used for recurrent ischemic chest discomfort when no contraindication exists.

Beta-blocker therapy may be appropriate in ACS when there are no contraindications such as:

1.      Acute decompensated heart failure

2.      Low-output state

3.      Significant bradycardia

4.      Advanced atrioventricular block without pacing

5.      Increased risk of cardiogenic shock

6.      Severe active bronchospasm

8.7 Coronary Angiography and Revascularization

The patient requires urgent invasive coronary angiography, with exact timing determined by ongoing symptoms and hemodynamic or electrical stability.

This is not an outpatient observation or routine stress-testing scenario.

If significant culprit coronary disease is identified, revascularization should be performed when appropriate.

Revascularization may involve:

1.      Percutaneous coronary intervention

2.      Coronary artery bypass grafting

The optimal strategy depends on:

1.      Coronary anatomy

2.      Lesion complexity

3.      Extent of coronary disease

4.      Comorbidities

5.      Surgical risk

6.      Patient-specific factors

Wellens syndrome therefore requires urgent coronary angiographic assessment with revascularization as indicated, rather than assuming that PCI is automatically the definitive therapy in every patient.

9. Stress Testing

Exercise or pharmacologic stress testing should not be performed in a patient with a suspected Wellens pattern before coronary anatomy has been appropriately evaluated.

Increasing myocardial oxygen demand in the presence of severe coronary disease may precipitate:

1.      Acute myocardial infarction

2.      Malignant ventricular arrhythmias

3.      Sudden cardiac death

A patient with a convincing Wellens pattern should therefore undergo urgent invasive coronary evaluation rather than routine provocative stress testing.

10. Clinical Significance

The original Wellens observations demonstrated that patients with this characteristic ECG pattern and unstable angina were at substantial risk of developing extensive anterior myocardial infarction when treated without early coronary intervention.

The syndrome should therefore be regarded as an important warning pattern of severe coronary disease, not as a benign T-wave abnormality.

Modern ACS management allows earlier diagnosis, angiography, and revascularization. Therefore, historical rates of progression to anterior myocardial infarction should not be automatically applied to contemporary treated populations.

11. Key Clinical Insight

A pain-free patient with recent anginal chest pain and characteristic biphasic or deeply symmetric inverted T waves in V2 through V3, preserved R-wave progression, no pathologic Q waves, and little or no ST-segment elevation should be considered to have a Wellens pattern until appropriately evaluated.

In this patient, the biphasic T waves with initial positivity and terminal negativity in V2 through V3 during a pain-free interval represent a biphasic Wellens pattern, commonly termed type A in contemporary usage.

Normal serial troponin measurements do not eliminate the risk of severe LAD disease or transient coronary occlusion with reperfusion.

The appropriate approach is high-risk ACS management, avoidance of stress testing, parenteral anticoagulation, and urgent invasive coronary angiography with revascularization when indicated.

Because type A and type B labels have occasionally been used inconsistently in the literature, the ECG morphology should always be explicitly described.

References

1.      Rao SV, O'Donoghue ML, Ruel M, Rab T, Tamis-Holland JE, Alexander JH, et al. 2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes. Journal of the American College of Cardiology. 2025;85(22):2135-2237. doi:10.1016/j.jacc.2024.11.009.

2.      Mills NL, Newby LK, Zaman S, et al. Fifth Universal Definition of Myocardial Infarction (2026). Journal of the American College of Cardiology. 2026;88(11):1314-1368. doi:10.1016/j.jacc.2026.07.025.

3.      de Zwaan C, Bär FW, Janssen JH, Cheriex EC, Dassen WR, Brugada P, Penn OC, Wellens HJJ. Angiographic and clinical characteristics of patients with unstable angina showing an ECG pattern indicating critical narrowing of the proximal LAD coronary artery. American Heart Journal. 1989;117(3):657-665. doi:10.1016/0002-8703(89)90742-4.