ABSTRACT
Objective To evaluate the short-term effect of low atrial septum pacing and different pacing frequency to prevent atrial fibrillation in patients with sick sinus syndrome . The electrophysiological mechanism would be ana-lyzed. Methods Thirty eight sick sinus syndrome patients were randomly divided to right atrial appendage pacing group and low atrial septum pacing group. The conduction time from P wave to left atrial and left atrioventricular in-terval was measured at different atrial pacing frequency. The effects of different atrial pacing frequency on interatrial conduction time were analyzed. The occurrence of atrial fibrillation was compared within an average one year follow-up period. Results ①There were no differences in basic information before treatment between the two groups. ②There were no complication, pacing and sensing dysfunction between the two groups.③The occurrence of atrial fi-brillation in low atrial septal group was lower than that in right atrial appendage pacing group. Similarly, the con-duction time from P wave to left atrial was shorter and left atrioventricular conduction time was longer in low atrial septal group. The difference was statistically significant.④ Left atrioventricular interval was longer in high pacing frequency(80 bpm) compared to low pacing frequency(60 bpm) between the two groups. The difference was statis-tically significant. Conclusion In sick sinus syndrome patients, the occurrence of atrial fibrillation is lower on low-er atrial septal group. Increasing atrial pacing percentage may be enhanced the effect. The mechanism may be asso-ciated with shortened interatrial conduction and extended left atrioventricular interval, which improves interatrial and left atrioventricular synchrony eventually.