Aprindine-induced polymorphous ventricular tachycardia.

Five cases of aprindine-induced polymorphous ventricular tachycardia (torsade de pointes) are presented. In four cases, polymorphous ventricular tachycardia appeared after the oral administration of 400 mg of aprindine. One patient had mild hypokalemia at the time of polymorphous ventricular tachycardia so that a direct cause and effect relation between the drug and the tachycardia cannot be established. All five patients manifested Q-T prolongation and recurrent syncope due to polymorphous ventricular tachycardia. In all five, polymorphous ventricular tachycardia subsided once administration of aprindine was discontinued.

Hypomagnesemia and ventricular tachycardia: a complication of ulcerative colitis and parenteral hyperalimentation in a nondigitalized noncardiac patient.

A nondigitalized patient without heart disease, but with ulcerative colitis on parenteral hyperalimentation, developed ventricular tachycardia in association with hypomagnesemia. Magnesium infusions were successful in suppressing the arrhythmia, but because of ongoing fecal losses, hypomagnesemia and ventricular tachycardia recurred each time the infusion was stopped. After total colectomy, the patient remained normomagnesemic and free of arrhythmias. The few previous descriptions of arrhythmias attributed to hypomagnesemia in nondigitalized patients are reviewed. The importance of recognizing hypomagnesemia as an easily reversible cause of arrhythmias is stressed.