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Macroscopic T-Wave Alternans in QTc Prolongation: A Warning Sign Before Torsades de Pointes
Aishwarya Arunkumar Kamble1, Ramy Doss2, Jay Jaiswal2
1Department of Internal Medicine, St Mary Medical Center, Langhorne, Pennsylvania, USA.
JACC. Case Reports
|July 30, 2026
Summary
Macroscopic T-wave alternans signals severe repolarization instability and risk of dangerous heart rhythms. Promptly address QT-prolonging factors and electrolyte imbalances to prevent ventricular arrhythmias.
Area of Science:
- Cardiology
- Electrophysiology
- Internal Medicine
Background:
- Alcohol use disorder can precipitate serious cardiac complications.
- Delirium tremens is associated with significant physiological disturbances.
- QT prolongation and T-wave alternans are known risk factors for ventricular arrhythmias.
Purpose of the Study:
- To describe a case of malignant ventricular arrhythmias associated with macroscopic T-wave alternans.
- To highlight the clinical significance of T-wave alternans in the context of alcohol-induced cardiac events.
Main Methods:
- Case report of a 28-year-old male with alcohol use disorder.
- Electrocardiographic monitoring for QT prolongation and T-wave alternans.
- Echocardiography to assess left ventricular function.
Main Results:
- The patient presented with delirium tremens, QT prolongation, and macroscopic T-wave alternans.
- These findings preceded episodes of torsades de pointes and ventricular fibrillation.
- Echocardiography revealed a dilated left ventricle with severely impaired ejection fraction (<20%).
Conclusions:
- Macroscopic T-wave alternans is a critical indicator of profound repolarization instability.
- It predicts imminent polymorphic ventricular tachycardia and sudden cardiac death.
- Immediate management includes removing QT-prolonging agents, correcting electrolytes, and administering magnesium sulfate.
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