Proarrhythmia during drug treatment of supraventricular tachycardia: paradoxical risk of sinus rhythm for sudden death.

The purpose of this review is to summarize available data concerning proarrhythmia during drug therapy for supraventricular tachycardia. Patients were included in this review if 4 elements of treatment were available from the citation: (1) presence or absence of heart disease; (2) type of supraventricular tachycardia; (3) type of antiarrhythmic drug; and (4) type of proarrhythmic event. Citations spanning the years 1922-1995 yielded 56 reports and 195 events meeting the inclusion criteria. Atrial fibrillation was the most common arrhythmia and occurred alone in 76% of patients. Heart disease was present in 96% of patients. Proarrhythmic events were associated with 8 antiarrhythmic drugs in a total of 195 administered regimens. An adverse arrhythmic event was reported most frequently with quinidine (72%). Torsades de pointes was the most common of the documented proarrhythmic events (61%). Although supraventricular tachycardias are rarely in themselves life-threatening, symptoms may be disabling for many patients, and their lifestyle may be measurably improved by the maintenance of sinus rhythm. An algorithm is presented that takes into account the factors that predispose to proarrhythmia; it attempts to minimize the risk of treating these patients with antiarrhythmic drugs.