What is the management approach for a patient with biphasic T waves on an electrocardiogram (ECG)?

Management of Biphasic T Waves on ECG

Biphasic T waves with a negative portion ≥1 mm in depth in ≥2 contiguous leads require further evaluation to exclude underlying structural heart disease, particularly cardiomyopathy and critical coronary artery stenosis. 1

Clinical Significance and Risk Assessment

Biphasic T waves represent an abnormal repolarization pattern that warrants the same level of concern as frank T-wave inversion. While there is limited specific data on biphasic T waves in isolation, expert consensus recommends treating them similarly to T-wave inversions when the negative component meets pathological criteria. 1

Key risk stratification factors:

• Location matters critically: Biphasic T waves in lateral leads (V5-V6, I, aVL) or inferolateral territories are particularly concerning for cardiomyopathy, especially hypertrophic cardiomyopathy (HCM). 1

• Anterior distribution (V2-V3): When biphasic T waves appear in precordial leads V2-V3, this may represent Wellens' syndrome pattern, which is highly specific for critical proximal left anterior descending (LAD) coronary artery stenosis and impending myocardial infarction. 2, 3

• Depth of negative component: The negative portion must be ≥1 mm (0.1 mV) in depth in ≥2 contiguous leads to be considered pathological. 1

Immediate Diagnostic Workup

Step 1: Exclude acute coronary syndrome

• Check cardiac biomarkers (high-sensitivity troponin) immediately. 4
• Assess for associated ST-segment changes—ST elevation or depression with biphasic T waves significantly increases concern for acute ischemia. 4, 5
• Review clinical presentation: chest pain, dyspnea, syncope, or family history of sudden cardiac death. 1

Step 2: Obtain transthoracic echocardiography

• Evaluate for structural heart disease including HCM, dilated cardiomyopathy, and regional wall motion abnormalities. 1, 4
• Assess left ventricular wall thickness—males with 13-16 mm represent "grey zone" hypertrophy requiring additional testing. 1

Step 3: Consider age and ethnicity-specific normal variants

• In children <16 years, biphasic T waves in V1-V3 may represent normal juvenile pattern. 1
• In Black athletes, anterior T-wave changes (V1-V4) preceded by J-point elevation may be normal training-related findings. 1
• In adults ≥20 years, biphasic T waves in leads V5-V6 are never normal and always require investigation. 1

Advanced Cardiac Imaging

When echocardiography is non-diagnostic or shows borderline findings:

• Cardiac MRI with gadolinium enhancement is the gold standard for detecting subtle myocardial abnormalities, fibrosis (late gadolinium enhancement), and apical/lateral wall hypertrophy that may be missed on echocardiography. 1, 4

• If cardiac MRI is unavailable, contrast-enhanced echocardiography should be performed. 1

Risk-Based Management Algorithm

High-risk features requiring urgent coronary angiography:

• Biphasic T waves in V2-V3 with history of chest pain (Wellens' pattern). 2, 3
• Associated ST-segment elevation. 4
• Elevated cardiac biomarkers with ongoing symptoms. 4

Intermediate-risk features requiring comprehensive evaluation:

• Biphasic T waves in lateral or inferolateral leads. 1, 4
• Normal initial troponin but persistent symptoms. 4
• "Grey zone" left ventricular hypertrophy (13-16 mm in males). 1

For intermediate-risk patients, additional testing includes:

• Exercise ECG testing to evaluate for inducible ischemia and exercise-induced arrhythmias. 1, 4
• 24-hour Holter monitoring to detect ventricular arrhythmias, which may support diagnosis of HCM and aid risk stratification. 1

Activity Restriction

Temporary restriction from competitive athletics should be considered for athletes with biphasic T waves of uncertain clinical significance until secondary investigations are completed. 1

Long-Term Surveillance

Even when initial evaluation is normal, serial cardiac imaging and ECG monitoring are mandatory for patients with concerning biphasic T-wave patterns, as cardiomyopathy phenotypes may develop over time. 1, 4, 5

• Repeat echocardiography or cardiac MRI at 6-12 month intervals initially. 1
• More frequent monitoring for patients with family history of cardiomyopathy or sudden cardiac death. 1

Critical Pitfalls to Avoid

• Do not dismiss biphasic T waves as "non-specific changes"—they may represent the earliest manifestation of inherited cardiomyopathy before structural changes become evident. 4, 5

• Do not assume normal initial imaging excludes disease—cardiomyopathy phenotypes can emerge during follow-up, particularly in young patients. 1, 4

• Beware of T-wave pseudonormalization—previously biphasic or inverted T waves that suddenly normalize may indicate acute coronary occlusion rather than improvement. 3

• Consider non-cardiac causes in appropriate clinical contexts: central nervous system events (seizures, intracranial hemorrhage), tricyclic antidepressants, and phenothiazines can all cause profound T-wave abnormalities. 5, 6