Catheter ablation of paroxysmal atrial fibrillation in patients with sick sinus syndrome

Sick sinus syndrome (SSS) frequently coexists with atrial fibrillation (AF). The results of AF ablation in patients with SSS have not been fully evaluated. We retrospectively investigated 65 patients with paroxysmal AF (PAF) and SSS who underwent AF ablation using either radiofrequency (n=50) or cryoballoon ablation (n=15) in our institute. Forty-nine (75.4%) patients had a median of 5.6 (4.8-6.0)s of documented sinus pauses prior to the procedure (42 patients on antiarrhythmic drugs), and were observed when AF terminated in 47 patients. Successful pulmonary vein isolation was achieved in all, and substrate modification was added in 3 patients. Freedom from recurrent atrial arrhythmias after single procedures was 58.7, 45.2, and 38.9% at 1, 2, and 3years after the initial procedure. During a 23.4 (11.1-40.7) month median follow-up and after 1.4 +/- 0.6 sessions, 80.6% of patients were free from arrhythmia recurrence; however, permanent pacemaker implantations were required in 9 (13.8%) patients at a median of 5.3 (2.9-21.0)months after initial procedures. The average heart rate did not significantly differ before or a median of 2.5 (1.2-5.3) months post-procedure (76.7 +/- 17.4 vs. 73.5 +/- 14.6bpm, p=0.90). Multivariate analyses revealed that larger left atrial diameters [odds ratio (OR)1.21, 95% confidential interval (CI)1.01-1.45, p=0.042] were independent predictor of AF recurrence, and SSS type 1 was the sole predictor of pacemaker implantations (OR 10.30, 95% CI 1.38-76.7, p=0.023), respectively. AF ablation obviated permanent pacemaker implantations in the majority of the patients with SSS and PAF, and SSS type 1 was a sole factor predicting pacemaker implantations.