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

Abstract

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.

Formula to estimate left atrial volume using antero-posterior diameter in patients with catheter ablation of atrial fibrillation

“…computed tomography (CT), an examination that is required for other purposes, [6] such as: calculation of the coronary calcium score or angio-tomography of the coronary arteries. [7] There are different methods for estimating left atrial volume using one diameter of the LA: the prolate ellipsoid formula, the sphere formula, and the cube formula.…”

“…Current guidelines recommend AP diameter for LA size assessment, but volume is a more objective measurement to evaluate LA dilatation. In addition to echocardiography, other imaging techniques can be used, the most accurate being computed tomography (CT), an examination that is required for other purposes, [6] such as: calculation of the coronary calcium score or angio-tomography of the coronary arteries [7] …”