Predictors of neuromodulation during single-shot thermal atrial fibrillation ablation: a computed tomography imaging analysis

Background: Ganglionated plexi (GPs) are part of the cardiac autonomic nervous system (CANS), which play an important role in the induction and maintenance of atrial fibrillation (AF). Because of the anatomic proximity of the pulmonary veins with GPs, pulmonary vein isolation (PVI) using thermal (radiofrequency (RF) or cryo) ablation, has been shown to concomitantly affect the GPs, as suggested by increased heart rate (HR) after ablation. Right superior pulmonary vein (RSPV) isolation has been reported to have the most evident inhibitory responses to the CANS via modulation of the anterior right ganglionated plexus. Nonetheless, there are also cases with little to no effect on neuromodulation post-ablation. Purpose: To assess the clinical and anatomical predictors of thermal ablation-induced CANS changes, as assessed via variations in resting HR post-ablation. Methods: We retrospectively analyzed consecutive patients with symptomatic paroxysmal AF who underwent first-time PVI by cryoballoon (CB) or RF balloon (RFB) between January 2022 to November 2022. Patients who were not in sinus rhythm, had cardiac implantable electronic devices, or did not have a contrast-enhanced computed tomography before the ablation were excluded. Pre-ablation and 24-hour post-ablation ECGs in sinus rhythm were collected and analyzed to assess HR. Results: A total of 83 patients (CB group, n = 43 vs RFB group, n = 40) were included in the analysis. Baseline patients' characteristics were similar between the two groups (Table 1). A significant HR increase (ΔHR ≥ 15 bpm) at 24h post-ablation occurred in 31 patients [CB group 16 (52 %), RFB group 15 (48 %)]. Predictors of increased HR were the distance between superior vena cava (SVC) and RSPV (OR 0.51, CI 0.35 - 0.75, p value < 0.01) and age (OR 0.94, CI 0.89 - 0.99, p value < 0.01) (Table 2). Conclusions: Single-shot thermal PVI influences the CANS, especially in patients with a shorter SVC - RSPV distance and in younger patients. (Table Presented).