Anatomic location of pulmonary vein electrical disconnection with balloon-based catheter ablation

Introduction:  Balloon-based catheters are an emerging technology in catheter ablation for atrial fibrillation, which aim to achieve consistent and rapid ablation encirclement of pulmonary veins (PVs). Recent emphasis has been placed on achieving more proximal electrical isolation within the PV–left atrial (LA) junction. We sought to evaluate the precise anatomic level of PV electrical disconnection with current design balloon-based catheters.
Methods and Results:  Thirteen patients with drug-refractory paroxysmal atrial fibrillation undergoing balloon catheter ablation with the endoscopic laser system (CardioFocus) or the high frequency-focused ultrasound system (ProRhythm) underwent electroanatomic mapping (EAM) of the left atrium. Intracardiac echocardiographic (ICE) imaging was used for visualization of the position of the balloon catheter during energy delivery. Detailed point analysis of the location of electrical disconnection was then documented on EAM and with ICE.
Successful electrical isolation was achieved in all 52 PVs. Despite ICE imaging confirming balloon catheter position at the antrum of the PVs, the location of electrical disconnection was demonstrated to be at or near the tubular ostium of the PVs on EAM and on ICE in all patients.
Conclusion:  Current generation balloon-based catheter ablation achieves electrical isolation distal in the LA–PV junction. This may limit the results of such systems in treating nonparoxysmal forms of atrial fibrillation.