Definition of the local cardiac coordinate system (C, L, R) relative to the LV: The LV long-axis is defined as the line from the mid of the mitral valvular opening to the LV apex. The long-axis was calculated separately per filling phase (i.e. one for early filling and another for late filling). The center of the vortex ring was projected on this long-axis. The distance of the projected point to the MV and to the vortex center defined the vortex’s longitudinal (L) and radial (R) coordinates as illustrated in (a), respectively. Both L and R distances were normalized to the long-axis length and to the basal endocardial radius (measured on a reformatted short-axis slice), respectively to provide dimensionless parameters. Circumferential (C) Coordinate is defined as the angle between the septal landmark (the anterior attachment of the RV free wall with the LV) and the vortex center as illustrated in cross-sectional view (b). the vortex ring orientation (α) measured as angle between the LV long-axis vortex and a fitting plane of the vortex ring, where an orientation of 90° means a vortex ring is perpendicular to the LV long-axis as shown in (c).