Long-term efficacy of antitachycardia pacing for supraventricular and ventricular tachycardias.

Over a 14-year period, 53 patients received implanted pacemakers to assist in the control of recurrent tachycardias. Indications were: prevention of tachycardia in 2 patients with supraventricular tachycardia (SVT), and 4 with ventricular tachycardia (VT); termination of tachycardia (15 SVT, 20 VT); and long-term periodic programmed electrical stimulation with potential for tachycardia termination (12 VT). Pacemakers for prevention of VT were implanted in 3 patients with prolonged QT interval syndromes and 1 in whom Holter monitoring showed a significant reduction in ectopic activity during pacing. Pacers were implanted for tachycardia termination only after patients underwent a rigorous protocol aimed at achieving 100 trials of the proposed modality. Patients with tachycardia also requiring antibradycardia pacemakers received pacemakers capable of noninvasive programmed stimulation for use during follow-up. There were no tachycardia recurrences among those patients in whom pacemakers were implanted for prevention. Pacers capable of outpatient programmed stimulation were useful, and it may be desirable to expand their use. The 15 patients with pacers designed for termination of SVT were followed for a mean of 68 months. Among these, actuarial continuation of pacing efficacy was 93% at 1 year, and 78% at 5 years. The 20 patients with pacers for termination of VT were followed for a mean of 37 months. Actuarial efficacy was 78% at 1 year, and 55% at 5 years. Sudden death occurred in 4 of these patients, none clearly pacer related. Pacemakers can play a major therapeutic role in some patients with recurrent tachycardias. The role of such pacemakers in patients with VT may be expanded with the advent of combined pacer-defibrillators.(ABSTRACT TRUNCATED AT 250 WORDS)