CONGRESS ABSTRACT

Introduction: Cardioneuroablation (CNA) is a transcatheter ablation technique targeting atrial parasympathetic ganglia to reduce vagal response in conditions like vaso-vagal syncope and functional atrioventricular block (AVB). Differentiating between vagal hypertonia and intrinsic conduction system damage is essential before considering CNA. In cases of intermittent bradycardia and AVB that improve with physical exertion, a vagal origin is suspected, while persistent AV block points to intrinsic sinoatrial or atrioventricular node dysfunction. Case Report: A 15-year-old male with history of recurrent syncope since birth was monitored over several years with a Loop Recorder, documenting episodes of second- and third-degree AVB. In June 2023, an ergometric test showed chronotropic increase and periods of 1:1 AV synchronization, raising suspicion of a vagal component. The atropine test showed persistence of atrioventricular conduction block with an increase in junctional frequency. Nevertheless, considering the patient's young age, it was decided to proceed with CAN in November 2023. The procedure involved ablation of the inferior paraseptal ganglionated plexus under fluoroscopic guidance. Following the procedure, stable 1:1 AV conduction was achieved. Follow-up: Post-procedure, the patient remained asymptomatic, with telemetric monitoring showing stable 1:1 AV conduction and first-degree AV block. Holter ECGs at 1, 3, and 12 months showed occasional second-degree AVB during the night. Conclusions: This case highlights the efficacy of CNA in treating atrioventricular block with a suspected functional component, offering a promising alternative to pacemaker implantation in select young patients, thereby avoiding long-term pacemaker-related complications.