Impact of different energy sources on the cardiac autonomic nervous system in the setting of single-shot pulmonary vein isolation

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: The cardiac autonomic nervous system is an epicardial neural network composed of ganglionated plexi (GPs) and interconnecting neurons, which plays a significant role in the induction and maintenance of atrial fibrillation (AF). Targeted GPs ablation in addition to pulmonary vein isolation (PVI) has been associated with superior AF outcomes. Due to the anatomical proximity of the GPs with the pulmonary veins, PVI with cryoballoon catheter ablation (CBA) has shown to concomitantly affect the GPs, as documented by increased heart rates (HR) after ablation. Recently, pulsed-field ablation (PFA) has emerged as a safe and effective non-thermal alternative for single-shot PVI, with specific selectivity for the cardiac tissue. The impact of PFA on the cardiac autonomic nervous system is still to be elucidated. PURPOSE: To assess the effect of PFA on the cardiac autonomic nervous system, evaluated with the variation in resting heart rate pre- and post-ablation. METHODS: We retrospectively included all consecutive patients with symptomatic paroxysmal AF undergoing first-time PVI with the multispline PFA catheter between January and September 2022. They were compared with consecutive patients undergoing PVI with CBA in the same study period. Patients not in sinus rhythm before ablation or with cardiac implantable electronic devices were excluded. All antiarrhythmic drugs were discontinued at least 3 days before ablation. Pre-ablation and 24-hour post-ablation ECGs in sinus rhythm were collected and analysed to assess HR. RESULTS: A total of 90 patients (PFA group, n=30 vs CBA group, n=60) were included in the analysis. Baseline patients’ characteristics were similar between the two groups (Figure 1). Pre-ablation HRs in the PFA and the CBA groups were 64.2 ± 10.3 bpm and 64.2 ± 12.8 bpm, respectively. Vagal reactions during ablation occurred more frequently with PFA than CBA (77% vs 38%, p=0.001). After 24h post-ablation, the HR increase in the PFA and CBA groups was 2.2 ± 5.4 bpm and 12.4 ± 11.9 bpm, respectively (p<0.001, Figure 2). CONCLUSION: PVI with the novel multispline PFA catheter is associated with less increase in HR 24 hours after ablation compared to CBA. This effect may be the result of tissue selectivity of PFA for cardiomyocytes, which has minimal effect on extracardiac structures, including the cardiac autonomic nervous system. [Figure: see text] [Figure: see text]