Pranav Bhagirath

95 Left atrial sphericity: a promising parameter to predict response to ablation the area-weighted centers of each triangle in the mesh. The best-fit sphere for the LA could then be computed using the distances between the center-of-mass and each triangle in the mesh. The mean of these individual distances provided the radius (µ) of the sphere of best-fit. The standard deviation (σ) of these distances was also calculated. LASP was then calculated as a ratio: 1 - σ/ µ ( figure 1 ). Figure 1. Calculation of LA sphericity. Posterior view of the left atrial (LA) triangular mesh, right side cropped for illustration purpose. The LA center-of-mass (white dot) can be computed using the area-weighted centers of each triangle in the mesh, example point 1 to 3. The mean and standard deviation of the individual distances between these points and the center-of-mass can then be used to calculate the LA sphericity. LSPV indicates left superior pulmonary vein; LIPV, left inferior pulmonary vein; LA, left atrium.