Long-Term Results of Antitachycardia Pacing in Patients with Supraventricular Tachycardia (original) (raw)

1989, Pacing and Clinical Electrophysiology

Results of Antitachycardia Pacing in Patients with Supraventricular Tachycardia. Between 1979 and 1984 the Cybertach-60, {Intermedics, Inc. Model 262-01}, a programmable, automatic antitachycardia pacemaker was implanted in 31 patients who had drug-re/ractory supraventricular tachycardia (SVTJ. The patients have been followed for a total of 64-108 (mean 84 months). All patients were symptomatic and had /ailed two or more drugs and six patients had required prior DC cardioversion. The mechanism o/supraventricuJar tachycardia was atrioventricular (AV) nodal reentry in six patients, AV reentry in four patients, and atrial tachycardia in one patient. Preoperatively all patients had reJiable termination of the tachycardia without induction of atrial jibriliation by pacing methods available to Cybertach-60. Postimplant, Cybertach-60 reliably terminated all episodes o/tachycardia without ancillary drug therapy. Nevertheless, at iong-term foUow-up antitachycardia pacing was effective and safe in the minority (36%}. with only four patients out of eleven still using a pacemaker for supraventricu/ar tachycardia. One of these four patients required additional drug therapy. In one of the patients, the Cyhertach-60 was replaced after 78 months by a more advanced device, (Intertach, Intermedics, Inc.) because of a depleted Cybertach-60 battery. In seven patients who no longer use antitachycardia pacing for termination of tachycardia, one patient developed atrial jibrilJation during tachycardia termination (at 58 months postimplant). Three patients experienced induction of tachycardia or atrial ^briiiation by the pacemaker due to undersensing of sinus P waves (at 36, 48, and 51 months}. One patient had inappropriate rate detection while in sinus rhythm triggering the tachycardia termination burst from the pacemaker and subsequent SVT induction. Although pace termination of supraventricuJar tachycardia was effective in two patients, they chose elective ablation (AV nodal and accessory pathway, respectively, at 74 and 6 months) due to frequent symptomatic SVT. (PACE, VoJ. 12, fune 1989} antitachycardia pacing, supraventricular tachycardia Address for reprints: Ingela Schntttger, M.D., Cardiology Divi-i r L i sion.