Physiology-Guided Selective Posteromedial Left Ganglionated Plexus Cardioneuroablation for Functional Paroxysmal Atrioventricular Block

BACKGROUND: Functional atrioventricular (AV) block is a vagally mediated bradyarrhythmia with preserved His-Purkinje conduction. Cardioneuroablation targets parasympathetic inputs as an alternative to pacing. CASE SUMMARY: A 27-year-old woman with recurrent syncope had paroxysmal functional AV block on ambulatory monitoring. Baseline conduction intervals were normal, while programmed atrial stimulation induced supra-Hisian block. Extracardiac vagal stimulation (ECVS) reproducibly triggered high-grade AV block. High-density mapping identified fractionated electrograms at the posteromedial left ganglionated plexus (PMLGP). Selective radiofrequency ablation was performed. After ablation, ECVS no longer induced AV block. The patient remained asymptomatic without recurrence. DISCUSSION: This case demonstrates a physiology-guided cardioneuroablation approach integrating conduction system assessment, ECVS, and fractionation mapping to enable targeted ablation of the PMLGP. TAKE-HOME MESSAGE: Selective PMLGP ablation guided by ECVS and mapping can eliminate functional AV block and avoid permanent pacing.