Acute Electrophysiological Changes of Ventricular Myocardium Following Cardioneuroablation for Asystolic Reflex Syncope

What this Trial Is About

Researchers are evaluating the effects of cardioneuroablation (CNA) on the heart's electrical activity and vulnerability to dangerous ventricular arrhythmias in patients with reflex syncope that causes asystole. Reflex syncope is a condition where vagal nerve activity causes sudden heart pauses. CNA aims to reduce this by ablating parts of the parasympathetic nervous system affecting the heart. However, reducing parasympathetic protection may increase risk of ventricular arrhythmias, and this study seeks to understand these acute effects. The study involves 50 patients undergoing CNA, a procedure performed under general anesthesia using a radiofrequency catheter to ablate ganglionated plexi in the heart. The procedure targets parasympathetic nerve endings mainly in the atria but may affect ventricular nerves as well. During and after CNA, researchers will measure heart electrical parameters including QTc interval, QT dispersion, right ventricular action potential duration, and refractory periods. They will also assess susceptibility to ventricular arrhythmias using programmed ventricular stimulation before and after CNA, as well as after administering atropine and isoproterenol. Participants will be monitored closely during the procedure with ECG and invasive electrophysiology measurements. These include measuring heart rate changes, ventricular action potentials, and arrhythmia vulnerability. Follow-up includes ECG assessments one day before and after CNA. The main outcome is the inducibility of ventricular arrhythmias within two hours after CNA. Secondary outcomes include changes in QT intervals and ventricular electrical properties. The study will help clarify the safety and acute impact of CNA on ventricular arrhythmias in patients with reflex syncope.

Cardioneuroablation and Ventricular Proarrhythmia