Relationship between exercise tolerance and autonomic nervous system modulation after catheter ablation for paroxysmal atrial fibrillation.

Autonomic nervous system (ANS) modulation increases the heart rate (HR) after catheter ablation (CA) for paroxysmal atrial fibrillation (PAF). However, its influence on exercise tolerance (ET) is poorly understood. This single-center retrospective cohort study enrolled patients who underwent CA for PAF. To analyze the effects of ANS modulation on ET, cardiopulmonary stress testing was performed before and 3 and 12 months after CA. The final analysis included 25 patients in the cryoballoon ablation (CBA) group and 24 in the radiofrequency CA (RFCA) group. HR increased at 3 and 12 months after CA compared with preoperative values (64.8 ± 8.6 vs. 77.7 ± 10.9, p < 0.001; 64.8 ± 8.6 vs. 74.8 ± 11.4, p < 0.001). ANS modulation was more frequent in the CBA group than in the RFCA group at 3 and 12 months after CA (64% vs. 21%, p < 0.01; 48% vs. 4%, p < 0.01). However, no significant difference in ET was observed before and after CA (anaerobic threshold 15.2 ± 2.8 vs. 15.7 ± 2.8, p = 0.46; 15.4 ± 3.0 vs. 16.3 ± 3.9, p = 0.38; peak VO2 23.5 ± 5.7 vs. 24.4 ± 5.2, p = 0.44; 23.0 ± 6.0 vs. 25.3 ± 7.7; p = 0.43) at both 3 and 12 months after CA. ANS modulation was more frequently observed in the CBA group than in the RFCA group. ET was not worsened by ANS modulation after CA.