Alterations of heart rate variability after radiofrequency catheter ablation of focal atrial fibrillation originating from pulmonary veins

Background-Transient sinus bradycardia and hypotension have been reported a s complications during radiofrequency (RF) ablation of focal atrial fibrill ation (AF) originating from pulmonary veins (PVs). This study used heart ra te variability (HRV) to evaluate the effects of focal PVs ablation on auton omic function. Methods and Results-Thirty-seven patients with paroxysmal AF were referred for ablation. The study group included 30 patients who underwent transsepta l ablation of PVs, and the control group included 7 patients who underwent the transseptal procedure without ablation. The mean sinus rate and time-do main (standard deviation of RR intervals and root-mean-square of difference s of adjacent RR intervals) and frequency-domain (low frequency, high frequ ency, and low-frequency/high-frequency ratio) analyses of HRV were obtained by use of 24-hour Holter monitoring before and 1 week, 1 month, and 6 mont hs after ablation. All the triggering points of AF were from PVs, and they were successfully ablated, Severe bradycardia and hypotension were noted du ring ablation of PVs in 6 patients (group IA); 24 patients without the abov e complication belonged to group IB. Compared with preablation values, a si gnificant increase in mean sinus rate and low-frequency/high-frequency rati o and a significant decrease in standard deviation of RR intervals, root-me an-square of differences of adjacent RR intervals, low frequency, and high frequency were noted in groups IA and LB patients 1 week after ablation. Th e changes in HR and HRV recovered spontaneously in the 2 subgroups by 1 mon th later, These parameters of HRV did not change in the control group after the transseptal procedure. Conclusions-Transient autonomic dysfunction with alterations in HR and HRV occurred after ablation of focal AF originating from PVs.