Verapamil-Induced Atrial Fibrillation

To the Editor: Verapamil hydrochloride is highly effective for control of ventricular response in atrial fibrillation, 1 although ineffective in reversing acute-onset fibrillation to sinus rhythm. Recent data from studies in animals confirm that verapamil slows atrioventricular conduction, but suggest that it also enhances atrial fibrillation and counteracts the antifibrillatory effect of quinidine. 2 , 3 Preliminary findings indicate that in susceptible patients verapamil may increase the ease with which atrial fibrillation can be induced during electrophysiologic testing. 4 We report a case of atrial fibrillation in an apparently normal subject who received intravenous verapamil. A 26-year-old physician was given 10 mg of verapamil hydrochloride . . . No extract is available for articles shorter than 400 words.