Measurement of the segments dimensions. Schematic (A) and factual (B) illustration of the central vertical long axis slice delimited by the QPS software on which measure were performed to determine the volume of each of the 20 segments s of the polar map. Ns is the number of segment of the polar map at each level (basal, n = 6 segments; middle, n = 6 segments; apical, n = 6 segment; apex, n = 2 segments). Ds is the mean diameter of the ring made by Ns segments at each ventricular level, Ls is the long axis length, and Ts is the transverse thickness of the segments. LV, left ventricular cavity; RV, right ventricular cavity.