Multislice computed tomography versus intracardiac echocardiography to evaluate the pulmonary veins before radiofrequency catheter ablation of atrial fibrillation - A head-to-head comparison

OBJECTIVES The purpose of this study was to perform a head-to-head comparison between multislice computed tomography (MSCT) and intracardiac echocardiography (ICE). BACKGROUND Different imaging techniques have been used to visualize the pulmonary veins (PV) before radiofrequency ablation of atrial fibrillation. METHODS The PV and their atrial insertion were evaluated in 42 patients (35 men, 49 +/- 9 years) admitted for ablation of PV ostia. Ostia were measured in two directions (anterior-posterior and superior-inferior) with MSCT. Two-dimensional (2-D) measurements of PV ostia were performed with ICE. Results were compared, considering MSCT as the gold standard. Venous ostium indexes were calculated by dividing MSCT measurements in the anterior-posterior direction and the superior-inferior direction. RESULTS Common ostia of left PV were observed in 33 (79%) patients with MSCT and 31 (74%) patients with ICE. Common ostia of right PV were observed in 13 (31%) and 16 (38%) patients, respectively. Additional PV were observed in 13 (31%) patients with MSCT and in 7 (17%) patients with ICE. Ostial diameters by MSCT in the anterior-posterior direction were similar to 2-D measurements by ICE. By contrast, diameters by MSCT in the superior-inferior direction were significantly larger than 2-D diameters measured with ICE. Venous ostium indexes were 0.77 +/- 0.18 and 0.90 +/- 0.15 (p < 0.01) for left and right PV respectively, indicating an oval shape of particularly left PV ostia. CONCLUSIONS Variation in PV anatomy is frequently observed with both techniques. The sensitivity for detection of additional branches is higher for MSCT. Results of measurements of PV ostia suggest an underestimation of ostial size by ICE. Three-dimensional imaging techniques, such as MSCT, are required to demonstrate an oval shape of PV ostia. (C) 2005 by the American College of Cardiology Foundation.