Effects of Pulsed Field Ablation on Autonomic Nervous System in Paroxysmal Atrial Fibrillation: A Pilot Study

BACKGROUND Vagal responses and phrenic activation are commonly observed during pulsed field ablation (PFA). However, whether the vagal responses and phrenic activations are nerve dam-age or a neurological stress response due to electrical stimulation is unclear.OBJECTIVE The purpose of this study was to evaluate the effect of a PFA system for performing pulmonary vein isolation on the auto-nomic nervous system.METHODS Patients with paroxysmal atrial fibrillation (AF) who un-derwent PFA between August 2021 and November 2021 were included. Nerve injury biomarkers and heart rate variability were ob-tained preablation and postablation. Patients were scheduled to un-dergo magnetic resonance imaging and diffusion-weighted imaging to evaluate cerebral microembolus formation postablation.RESULTS Acute electrical isolation was achieved in 100% of pul-monary veins (n = 72) in the 18 patients. Mean total procedural time was 64.1 +/- 18.2 minutes, and mean fluoroscopy time was 12.3 +/- 3.5 minutes. Serum nerve injury biomarkers did not show any changes preablation and immediately postablation and 24 hours after ablation (all P >.05). Preablation and 30-day postabla-tion heart rate variability did not differ (all P >.05). Postablation diffusion-weighted imaging revealed no acute cerebral microembo-lus events. Moreover, there were no other procedure-related compli-cations. The 8-month Kaplan-Meier estimate of freedom from arrhythmia was 83% +/- 9%.CONCLUSION PFA does not induce nerve injury during pulmonary vein isolation for paroxysmal AF.