Sudden cardiac death while taking amiodarone therapy: the role of abnormal repolarization.

Torsade de pointes may occur as a complication of amiodarone therapy. We report a patient receiving amiodarone who was resuscitated from cardiovascular collapse and documented ventricular fibrillation. At subsequent electrophysiology study, while the patient was taking amiodarone therapy, monophasic action potentials with early after depolarisations were recorded which were not present when the patient was restudied 6 weeks after discontinuation of amiodarone. Early after-depolarisations may be important in the genesis of polymorphic ventricular tachycardia complicating amiodarone therapy.