Polymorphic Ventricular Tachycardia and Torsades in Methadone Therapy Captured by Loop Recorder

BACKGROUND: Methadone is associated with QT prolongation and risk of torsades de pointes, particularly at higher doses, and management becomes challenging when the precipitating factor cannot be eliminated. CASE SUMMARY: A 56-year-old man on high-dose methadone with an implantable loop recorder experienced 3 episodes of polymorphic ventricular tachycardia and ventricular fibrillation, including a prolonged 94-second syncopal event. Device electrograms demonstrated pause-dependent initiation with short-long-short sequences and marked QT prolongation preceding arrhythmia onset. Despite limited follow-up, he ultimately agreed to wearable cardioverter-defibrillator therapy and subsequent implantable cardioverter-defibrillator (ICD) placement for secondary prevention. DISCUSSION: This case highlights methadone-associated malignant ventricular arrhythmias, the importance of continuous rhythm monitoring, and the role of ICD insertion when the offending agent cannot be safely withdrawn. TAKE-HOME MESSAGE: In high-risk patients with recurrent ventricular arrhythmias on methadone, individualized monitoring and ICD therapy may be warranted.