Torsades de pointes: a rare complication of temporary pacing for permanent ventricular pacemaker failure

Torsades de pointes, a distinctive type of polymorphous ventricular tachycardia, may be induced by critically timed ventricular stimulation during electrophysiologic studies or, rarely, in patients with temporary or permanent ventricular pacemakers. The following case illustrates how, when temporary ventricular pacing is instituted to maintain heart rate in a patient with a defective permanent ventricular pacemaker, this potentially fatal arrhythmia may occur as a complication of interaction between the two pacemakers.