Evaluation of Intercaval Bundle Connection by Multisite Pacing and Right-Sided Pulmonary Vein Isolation

Area of Science:

• Electrophysiology
• Cardiac Anatomy
• Interventional Cardiology

Background:

• An intercaval bundle connection (IBC) between the right pulmonary vein (PV) and right atrium (RA) can impede successful PV isolation.
• The precise prevalence and anatomical distribution of IBCs require further investigation.

Purpose of the Study:

• To determine the frequency and anatomical distribution of IBCs using multisite pacing.
• To assess the relationship between IBCs and the outcomes of PV isolation procedures.

Main Methods:

• Analysis of 108 patients undergoing their first PV isolation via radiofrequency ablation.
• Creation of an activation map using multisite pacing from the RA, right inferior PV, and earliest activation site of the RA (EAS-RA) via right inferior PV pacing.

Main Results:

• Multisite pacing identified IBC in 100% of patients, significantly more than RA pacing alone (20.4%).
• The earliest activation site in the left atrium (EAS-LA) relative to the PV isolation line was classified as 'PV inside,' 'PV side,' or 'LA side.'
• An 'above' EAS-RA was associated with a 'PV inside' EAS-LA, which correlated with a higher frequency of additional ablation for the anterior carina.

Conclusions:

• Multisite pacing reliably visualizes the intercaval bundle connection (IBC).
• The anatomical location of the IBC, specifically its attachment site on the left atrium, impacts the need for additional ablation procedures targeting the right anterior pulmonary vein carina.