Long-term results of permanent atrioventricular sequential demand pacing.

Pervenous atrioventricular sequential demand pacemakers (AVSDPs) were implanted in 18 patients using an atrial electrode positioned in the right atrial appendage and a ventricular electrode positioned at the apex of the right ventricle. The indications included 13 patients with the sick sinus syndrome (72%), five of whom had the tachycardia-bradycardia syndrome, three with paroxysmal supraventricular tachycardia, one with cardiomyopathy and one with carotid sinus syncope. The follow-up ranged from 6 to 38 months, with a mean of 19.4 months (a total of 350 pacing months). Seventeen patients (94%) are asymptomatic. One patient had persistent episodes of paroxysmal supraventricular tachycardia. In the remaining patients with tachyarrhythmia, pacing alone (three patients) or in combination with antiarrhythmic drugs (four patients) controlled the tachyarrhythmia. There was one displacement of the atrial electrode (5.5%). Extrusion of the pacer occurred in three patients. It is concluded from this experience that AV sequential pacing is an effective technique and may be useful in patients with sick sinus syndrome, in patients with tachyarrhythmia and/or patients with poor myocardial function. However, continued research is needed to prolong battery life and to reduce the size of the pacemaker.