Cardioneuroablation in hypervagotonic bradyarrhythmias: physiological endpoints and outcomes in a retrospective single-centre cohort

Introduction

Cardioneuroablation (CNA) modulates cardiac ganglia to blunt hypervagotonia and vagally mediated bradyarrhythmias. Signals of benefit exist for reflex cardioinhibitory syncope phenotype, while guidance remains cautious pending randomised evidence.

Purpose

To quantify clinical and physiological effects of CNA in hypervagotonic bradyarrhythmias and assess age-related differences (<50 vs ≥50 years).

Methods

Retrospective, single-centre cohort (2018–2025). Adults treated with CNA for hypervagotonic syndromes (cardioinhibitory reflex syncope, vagal-induced sinus bradycardia, functional atrioventricular block) were included; exclusions were relevant structural disease, intra- or infra-His disease, or incomplete pre/post data.

Primary endpoints: clinical composite — freedom from syncope plus negative post–head-up tilt (HUT); and physiological — immediate heart rate (HR) rise and reduction in heart-rate variability (HRV). Secondary endpoints: sinus pause resolution, atrioventricular indices (Wenckebach, RR, PQ), re-intervention. Paired continuous outcomes used Wilcoxon; paired categorical outcomes used exact McNemar; prespecified subgroups by age.

Results

Twenty-eight patients were enrolled, presenting with a mean age of 38.2/ std 12.5 years. The majority of the cohort was male (n=19, 67.9%), with the remaining 9 patients (32.1%) being female. Comorbidities were documented in a minority of patients, specifically hypertension and dyslipidemia, each affecting 4 participants (14.3%).

Syncope burden fell from 43 to 3 episodes (-93%) comparing 1 year pre-CNA with 1 year post-CNA; median per patient 2 to 0 episodes; post-procedure syncope in 3/28 (11%) patients (Figure 1).

By an intraprocedural HR criterion (≥100 bpm or ≥20% rise), success was 13/19 (68%; <50 years vs ≥50 years: 9/14 (64%) vs 4/5 (80%). HRV decreased and atrioventricular parameters (PQ fell from 290 ms [250–300] pre-procedure to 190 ms [180–220] post-procedure; median paired change −100 ms; Wilcoxon P=0.004, indicating a significant shortening of AV nodal conduction time.

Conclusion(s)

The physiological effect of CNA is quantifiable using intraprocedural HR increase and post-procedural HRV attenuation. Clinically, syncope burden dropped by >90%, with a low recurrence rate. Age-stratified HR success suggests benefits not limited to younger vagal-predominant profiles. Given heterogeneous techniques and the limited sham-controlled randomised data, these findings are hypothesis-generating and consistent with current guideline caution.