Analysis of left atrial geometry:
A 3D reconstruction of the LA was created from the obtained 3D-RA image. The final LA model was exported as a mesh for further analysis in a custom developed software
package to automatically calculate LA volume, surface and sphericity parameters (Fig. 2) . The antero-posterior (AP) diameter was manually calculated from the obtained mesh by measuring the longest AP distance. All geometrical measurements, as well as the calculation of the LA sphericity and the LA center of mass were performed based on previously published literature.18