Abstract 2344: Pressure-guided Cryoballoon Isolation of the Pulmonary Veins for the Treatment of Paroxysmal Atrial Fibrillation
Background: Pulmonary vein (PV) isolation using a balloon-mounted cryoablation system is a new technology for the percutaneous treatment of atrial fibrillation (AF). Complete PV occlusion during balloon ablation has been shown to predict successful electrical isolation. The aim of this study was to correlate mechanical PV occlusion with changes in a pressure curve recorded at the distal tip of the cryoballoon catheter.
Methods: We analyzed 51 PVs in 12 patients (61±6 years-old) with paroxysmal AF. At first, PV occlusion via the cryoballoon was documented by changes in the pressure curve: once the PV is occluded, the pressure curve registered in the vein converts from a left atrial pressure curve (A) to a pulmonary artery pressure curve (B): the PV wedge curve (see Figure⇓). Occlusion was then confirmed by transesophageal echocardiography (TEE). Following 2 cryoablation applications, electrical PV isolation was assessed with a circumferential mapping catheter.
Results: Under the exclusive guidance of changes in the pressure curve at the tip of the cryoballoon, mechanical occlusion confirmed by TEE was achieved in 47 of 51 PVs (92%). Three PVs could only be occluded with the help of TEE. All 50 occluded veins were electrically isolated after cryoablation. One right inferior vein, which could not be occluded with the balloon displayed conduction post cryoablation, and was isolated by focal ablation.
Conclusions: Occlusion and therefore electrical isolation of PVs during cryoballoon ablation can be predicted by the appearance of a PV wedge curve at the tip of the catheter. This new straightforward parameter may facilitate the procedure.