Chronic Overdrive Pacing in the Control of Refractory Ventricular Arrhythmias

Eleven patients with recurrent ventricular tachycardia or ventricular fibrillation that was refractory to antiarrhythmic drugs were treated with long-term, overdrive atrial or ventricular pacing. Pacing rates ranged from 70 to 110 impulses per minute. In eight patients chronic pacing was successful and prevented recurrent ventricular tachycardia or ventricular fibrillation for periods of 6 to 46 months. In the other three patients chronic pacing was unsuccessful; they died within 5 weeks—two of recurrent ventricular tachycardia and one suddenly of unknown cause. Overdrive suppression was successful in all four patients with prepacing heart rates of 40 to 60 and in four of the seven patients with prepacing heart rates of 70 to 95. Long-term overdrive suppression of refractory ventricular arrhythmias is frequently successful, especially where prevailing heart rates are slow. It is also successful in a substantial number of patients with normal heart rates.