Distance between the Left Atrial Appendage and Mitral Annulus Evaluated by CARTO 3 Integrated Computed Tomography Imaging

Objective: To measure distances between pulmonary veins (PV) and mitral annulus (MA) using angiographic computed tomography (CT) and to compare them with the left atrial appendage-MA (LAA-MA) line. Materials and Methods: Data from 46 catheter ablation procedures for atrial fibrillation involving 36 males, mean age 53 years, range 27-78 years, were analyzed. Three types of mitral isthmus lines were measured using angiographic CT images integrated in the CARTO 3 system (Biosense Webster): the distance between the right superior PV and MA (RSPV-MA), the right inferior PV and MA (RIPV-MA), and the left inferior PV and MA (LIPV-MA). They were compared with the length of the LAA-MA line. Results: The mean value of LIPV-MA was 29 ± 11.2 mm, RIPV-MA 39 ± 8.2 mm, and RSPV-MA 48 ± 8.2 mm. The circumflex artery (CxA) and the coronary sinus (CS) were closest to the LIPV-MA line. Compared with the three isthmus lines, the LAA-MA was the shortest (24.7 ± 15.6 mm), and the difference was statistically significant (p < 0.05). Conclusion: The angiographic CT provided detailed information regarding the anatomy of the left atrium and distances between atrial structures. The LAA-MA was shorter than the other three lines with the CxA and CS situated at a distance.