Pacemaker reversion for suspected supraventricular tachycardia.

Overdrive atrial pacing was employed in twelve patients with suspected supraventricular tachycardia resistant to drug therapy. Eleven of these patients reverted to sinus rhythm with pacing either immediately or after a short episode of atrial fibrillation. In one patient, recordings from the atrial electrode indicated that a broad complex tachycardia was of ventricular rather than supraventricular origin. No complications were encountered and the procedure was well tolerated in all. Overdrive pacing is suggested as a safe alternative to DC cardioversion in drug-resistant supraventricular tachycardia, particularly in the presence of digitalis, in the elderly and in patients with chronic lung disease.