Mapping the Conduction System in Patients Undergoing Transcatheter Device Closure of Perimembranous Ventricular...

Area of Science:

• Cardiology
• Medical Imaging
• Electrophysiology

Background:

• Previous studies on the atrioventricular (AV) conduction system and perimembranous ventricular septal defect (pmVSD) relied on cardiopathological specimens.
• Understanding the spatial relationship between the conduction system and pmVSD is crucial for safe and effective device closure.

Purpose of the Study:

• To investigate the relationship between the AV conduction system and pmVSD using a 3-dimensional electroanatomic mapping system (EAMS).
• To assess the feasibility of EAMS for mapping the conduction system during device closure of pmVSD.

Main Methods:

• A prospective study included fifteen patients (age > 2 years, weight > 8 kg) with pmVSD undergoing device closure.
• 3-dimensional electroanatomic mapping system (EAMS) was used to map the conduction system's course and its relationship with the pmVSD before and after device implantation.

Main Results:

• The conduction system was consistently found posteroinferior to the pmVSD in all cases (100%).
• In 67% of patients, the conduction system was located away from the defect.
• Two patients developed transient right bundle branch block (RBBB) post-procedure, which resolved on follow-up; no high-grade AV block occurred.

Conclusions:

• 3D EAMS is a feasible and novel method for mapping the conduction system during pmVSD device closure.
• This technique offers valuable insights into the anatomy of the conduction system in congenital heart diseases, potentially improving procedural safety.