Pulmonary vein ostium shape and orientation as possible predictors of occlusion in patients with drug-refractory paroxysmal atrial fibrillation undergoing cryoballoon ablation.

AIMS: No specific data are available on the influence of pulmonary vein (PV) anatomy and shape on cryoballoon ablation (CA) catheter efficacy in delivering cryothermal energy and, consequently, in obtaining PV isolation.

METHODS AND

RESULTS

Among a larger series of patients (68) with drug-refractory paroxysmal atrial fibrillation who underwent CA in our department, 52 patients were included in our study. All of them had a multislice cardiac computed tomography (MSCT) before the procedure. We retrospectively evaluated their MSCT scans focusing our attention on PV ovality and orientation in the frontal plane. A fair inverse association was documented between the ovality index of the left PVs and the degree of occlusion (r=-0.486 and P<0.003 for the LSPV and r=-0.360 and P=0.033 for the LIPV), whereas no association was found between the ovality index of the right PVs and the degree of occlusion (r=-0.283 and P=0.083 for the RSPV and r=0.235 and P=0.093 for RIPV). Nevertheless, a strong inverse association was found between the orientation of the PV ostia and the degree of occlusion in each vein (r=-0.804 and P<0.001 for the LSPV, r=-0.415 and P=0.013 for LIPV, r=-0.798 and P<0.001 for the RSPV, and r=-0.867 and P<0.001 for RIPV).

CONCLUSION

Pulmonary vein ostium shape and orientation evaluated by MSCT proved to be useful in predicting the degree of occlusion obtained during CA.