Figure 3. (Upper left) The association between fractional area of contraction (FAC) and end-systolic elastance (Ees). (Upper right) The association between FAC and preload recruitable stroke force (PRSF). (Lower left) The association between circumferential fiber shortening (Vcfc) and Ees. (Lower right) The association between Vcfcand PRSF (n = number of observations; r = correlation coefficient).