Cardioneuroablation as a Therapeutic Approach for Functional AV Block Presenting Late After AVNRT Ablation

Area of Science:

• Electrophysiology
• Cardiac Arrhythmia Management
• Interventional Cardiology

Background:

• Atrioventricular block (AVB) is a rare but serious complication after atrioventricular nodal reentrant tachycardia (AVNRT) ablation.
• Patients undergoing AVNRT ablation face an increased risk of late-onset AVB and pacemaker implantation.
• Cardioneuroablation (CNA) is a potential alternative for syncope and conduction disorders, but its role in post-AVNRT AVB is unestablished.

Purpose of the Study:

• To evaluate the efficacy of Cardioneuroablation (CNA) in managing late-onset paroxysmal atrioventricular block (AVB) after successful AVNRT ablation.
• To assess CNA as an alternative to pacemaker implantation in this specific patient cohort.
• To investigate the procedural and clinical outcomes of CNA targeting specific ganglionated plexuses.

Main Methods:

• Prospective study of three patients with syncope due to late-onset AVB post-AVNRT ablation.
• Assessment of infrahisian and suprahisian conduction using atropine testing.
• Biatrial CNA performed using Ensite X EP System, targeting inferior paraseptal and left superior ganglionated plexuses with radiofrequency energy.
• Success defined by abolition of atropine response, no syncope recurrence, and normal conduction on Holter monitoring.

Main Results:

• Acute procedural success achieved in all three patients, with reduced antegrade Wenckebach point after RF ablation.
• Post-CNA atropine and tilt tests showed preserved conduction and vasodepressor responses, respectively.
• No syncope recurrence observed during 6-13 months of follow-up, with normal Holter monitoring results.

Conclusions:

• Cardioneuroablation (CNA) shows promise as an alternative to pacemakers for late-onset AVB following AVNRT ablation.
• Targeting the inferior paraseptal ganglionated plexus (IPSGP) may be critical for successful outcomes.
• Larger studies are warranted to confirm long-term efficacy and optimal techniques for CNA in this population.