OBJECTIVETo evaluate variations of pulmonary venous drainage and venous ostium index (VOI) in patients with atrial fibrillation (AF) prior to radio-frequency catheter ablation (RFCA) by MDCT pulmonary venography.

METHODS16-detector row CT pulmonary venography was performed in 64 AF patients referred to RFCA from June, 2005 to May, 2006. Variations in pulmonary venous drainage were observed in volume render imagines. Anterior-posterior and superior-inferior diameters of pulmonary venous ostium were measured on maximum intensity projection images. VOI derived from left superior, left inferior, right superior, right inferior pulmonary veins and variations in pulmonary venous drainage were calculated.

RESULTSClassic pulmonary veins anatomy was found in 11 patients (17.18%), early branching veins in 45 patients (70.31%), left common ostium in 5 patients (7.81%), right common ostia in 1 patient, right accessory (middle) pulmonary vein in 5 patients (7.81%) and left accessory (middle) pulmonary vein in 1 patient (1.56%). VOI of homolateral pulmonary veins and bilateral superior pulmonary veins were similar (P > 0.05) while there was a significant difference on VOIs derived from left superior and right inferior; two inferior, left inferior versus right superior veins (P < 0.05). Right inferior pulmonary venous ostium was most rounded and had the highest index (0.88) and left inferior pulmonary venous ostium was most oval and had the lowest index (0.72).

CONCLUSIONMultidetector row CT pulmonary venography (MDCT-PV) could provide valuable informations on pulmonary venous anatomy in AF patients referred to RFCA and should be used as a routine examination prior to the operation.