The risk factors of new-onset atrial fibrillation after pacemaker implantation

Objective. The aim of this study was to determine the incidence of newly detected atrial fibrillation (AF) in patients following dual-chamber pacemaker (PPM) implantation and to define the clinical predictors of new-onset AF in a Chinese cohort. Methods. A total of 219 patients without documented AF that underwent dual-chamber PPM implantation for sick sinus syndrome (SSS) (n=88) or atrioventricular block (AVB) (n=131) were prospectively studied. All patients were invited to follow-up at 1 month, 3 months and 6 months after the pacemaker implantation procedure, and once every 6 months thereafter. An atrial high-rate episode (AHRE) >= 5min and an atrial rate >= 180bpm was defined as AF. Results. During follow-up of 884 +/- 180 days, AF was detected in 56 (26%) patients. Using Kaplan-Meier survival curves with Logrank test, SSS patients with a cumulative percentage of ventricular pacing (Cum % VP) >= 60% had a significantly higher rate of new-onset AF compared to AVB patients (p=0.026) and SSS patients with Cum % VP <60% (p=0.018). On multivariate Cox regression analysis, higher Cum % VP independently predicted highermorbidity of newly detected AF (hazard ratio [HR] 1.01; confidence interval [CI] 1.00 similar to 1.02; p=0.035) among SSS patients. Larger left atrial (LA) dimension was a predictor of newly detected AF (HR 1.06; CI 1.01 similar to 1.14; p=0.046) in AVB patients. Conclusion. The incidence of AF following dual-chamber PPM implantation was relatively high in this Chinese cohort. High Cum % VP and larger LA dimension could independently predict new-onset AF after dual-chamber PPM implantation in SSS and AVB patients, respectively.