Effect of pacing method on risk of sudden death after atrioventricular node ablation and pacemaker implantation in patients with atrial fibrillation

BACKGROUND Sudden death may occur after radiofrequency catheter ablation of the atrioventricular node (AVN) and permanent pacemaker implantation. It is unclear whether a faster initial heart rate with gradual rate reduction decreases the risk of sudden death. OBJECTIVE To evaluate the effects of initial pacing at a faster rate after AVN ablation, with a gradual rate decrease over 3 months, on the rate of sudden death in patients with atrial fibrillation. METHODS We compared the rate of likely or possible procedure-related sudden death in 2 groups of patients who had AVN ablation and pacemaker implantation. The study cohort was treated between January 2005 and December 2009, and pacemakers were programmed to a lower rate of 90 beats/min after the procedure, with a monthly decrement of 10 beats/min until. 60 beats/min was reached. The control group was treated between Jury 1990 and December 1998 when pacemakers were programmed to a lower rate of 60 beats/min immediately after ablation. RESULTS The study cohort included 520 patients (mean age 73.6 +/- 10.3 years), and the control cohort comprised 334 patients (mean age 68.1 +/- 1.1 years). Sudden death deemed likely or possibly related to ablation and pacemaker implantation occurred in 1 patient in the study cohort (0.2%) and in 7 patients (2.1%) in the control group (P=.007). CONCLUSIONS Sudden death was significantly decreased in the study cohort compared to controls. The faster lower pacing rate immediately after AVN ablation with a gradual decrease is a plausible mechanism for the improved clinical outcome.