A 51-year-old woman was severely incapacitated because of intractable supraventricular tachycardias and rheumatic heart disease involving the aortic and mitral valves. The arrhythmias were not prevented by a variety of drug regimens, and over 200 cardioversions were done. It was believed that the arrhythmias had to be positively controlled if valvular surgery was to be successful. At open-heart surgery the aortic and mitral valves were replaced with ball-valve prostheses and the conduction bundle was divided in the region of the atrioventricular (AV) node. Permanent pacemaker leads were attached to the epicardium. Early postoperatively there was complete AV dissociation with a ventricular rate of 60 beats per minute. Later the ventricular rate slowed to 48 and a pacemaker was connected to the implanted leads for permanent ventricular pacing at 75 beats per minute.