Physiologic atrial cardiac pacing for the prevention of chronic atrial fibrillation associated with sick sinus syndrome.

Long-term results of physiologic atrial pacing have been analyzed for the possibility of avoiding the recurrence of paroxysmal atrial fibrillation and the progression to chronic permanent atrial fibrillation in patients with paroxysmal atrial fibrillation related to sick sinus syndrome. Seventy four patients were evaluated and divided into two groups; 39 patients underwent atrial pacing (AAI, 53%) and 35 had ventricular pacing by single-lead pacing (VVI, 47%). All patients had been evaluated periodically on an out-patient basis by 24 hour Holter monitoring. Basic rhythms in all AAI patients were based on atrial pacing, resulting from the suppression of paroxysmal atrial fibrillation. Basic rhythms in the VVI paced patients were variable, consisting of regular sinus rhythm, transient atrial fibrillation, and ventricular pacing in 30 of 35 patients in the VVI group. The remaining five patients progressed to chronic permanent atrial fibrillation (0% in AAI vs. 14% in VVI, p < 0.05). Thromboembolic complications were not observed in the AAI pacing group. Three patients demonstrated thromboembolic complications (0% in AAI vs. 8.6% in VVI, p < 0.05). The effect of preventing paroxysmal atrial fibrillation and the progression to chronic atrial fibrillation was evident in the AAI paced group, but VVI pacing cannot prevent paroxysmal atrial fibrillation and chronic atrial fibrillation. In addition, potential risks of thromboembolic complications caused by atrial fibrillation were not decreased in VVI paced patients.