Time-course changes in autonomic nervous system activity after pulsed-field ablation for paroxysmal atrial fibrillation: comparison with cryoballoon ablation

Background: The effect of pulmonary vein isolation (PVI) using pulsed-field ablation (PFA) on the autonomic nervous system (ANS) has not been well characterized. This study assessed changes in ANS activity following PFA using heart rate variability analysis, compared with changes after cryoballoon ablation (CBA). Methods: We retrospectively included patients who underwent de novo PVI for paroxysmal atrial fibrillation using PFA (n = 53) or CBA (n = 190). Frequency-domain analysis—including low- and high-frequency power (LF and HF)—and time-domain analysis of the RR interval and its standard deviation (SDNN) were performed using commercial software (MemCalc/Win, GMS), with 3-minute electrocardiograms recorded before ablation and at 1, 3, and 6 months post-ablation. Changes in parameters were compared between the two groups. Results: In the PFA group, the RR interval decreased at 1 month (932 ± 138 vs. 876 ± 127 ms, p = 0.001), whereas Log HF showed a nonsignificant decrease (1.86 ± 0.49 vs. 1.70 ± 0.52 ms², p = 0.078) and Log LF and SDNN remained unchanged. In contrast, the CBA group demonstrated significant reductions in Log HF (1.80 ± 0.57 vs. 1.20 ± 0.69 ms², p < 0.001), Log LF, RR interval (959 ± 159 vs. 804 ± 115 ms, p < 0.001), and SDNN at 1 month, persisting up to 6 months. Although both groups exhibited post-ablation decreases in the RR interval, the magnitude of change was smaller in the PFA group compared with the CBA group (ΔRR interval from baseline to 6 months: −61 ± 118 vs. −147 ± 153 ms; p < 0.001). Conclusion: PFA partially modulated the ANS, but its effect was distinctly less pronounced than that of CBA, reflecting differences in energy delivery and selective tissue response. Capsule Summary: PFA had a relatively mild impact on the autonomic nervous system, with smaller changes in heart rate and HRV parameters compared with CBA. These findings suggest that PFA’s tissue-selective energy delivery results in a gentler autonomic effect.