Cardioneuroablation in the management of neurocardiogenic syncope with extracranial validation: efficacy and effects on the regulation of the cardiac autonomic system – a combined retrospective–prospective cohort study

BACKGROUND: Neurocardiogenic syncope (NCS), particularly cardioinhibitory and mixed subtypes, remains a clinical challenge when refractory to conventional therapy. Cardioneuroablation (CNA) targeting the parasympathetic ganglionated plexi has emerged as a novel interventional option. This study evaluates the efficacy of biatrial CNA with extracardiac vagal stimulation (ECVS) validation in preventing recurrence and modulating cardiac autonomic regulation. METHODS: A single-center combined retrospective-prospective cohort study was conducted at a fourth-level institution in Colombia, including patients with cardioinhibitory or mixed-type NCS refractory to conventional treatment. CNA was performed targeting both atria with three-dimensional mapping, followed by ECVS via the internal jugular vein for pre/post validation. Primary outcome was the recurrence of syncope. Secondary outcomes included changes in heart rate variability (HRV) and quality of life (QoL) as assessed by 24-hour Holter monitoring and the SF-36 questionnaire, respectively. Mean follow-up was 24 months. Statistical analysis was performed using SPSS Statistics 28.0.0.0. RESULTS: Fifty-three patients (mean age 42.8 ± 10.1 years, 70% cardioinhibitory type) were included. Recurrence occurred in 7 patients (13.2%), with 86.8% syncope-free survival. HRV parameters decreased after CNA (SDNN: 137.03ms vs. 83.18ms; SDANN index: 79.12 vs. 39.35; RMSSD: 38.75ms vs. 13.91ms; p < 0.001), indicating vagal suppression. QoL improved significantly (SF-36 score: 81.91 vs. 94.62, p < 0.001). No major procedural complications or mortality were reported. CONCLUSION: CNA with ECVS validation is effective in reducing syncope recurrence, suppressing excessive parasympathetic tone, and improving QoL in patients with refractory neurocardiogenic syncope. These findings support its use as a therapeutic option in selected patients.