FIGURE 3.

Load-independent indices of LV systolic and diastolic function. (A) Characteristic indices of LV contractility and stiffness could be obtained by pressure-volume (P-V) analysis during reducing cardiac preload by the transient occlusion of vena cava inferior. Representative original recordings of P-V relations from one animal of each group during this maneuver were depicted. (B) Sensitive contractility indices, such as the slope of end-systolic pressure-volume relationship (ESPVR) and PRSW revealed comparable exercise-induced LV contraction improvement in both genders. (C) There was a notable difference regarding Tau, a load-independent parameter of LV active relaxation. In male rats a diastolic improvement was shown as indicated by decreased Tau values, whereas exercise was not associated with altered Tau in females. The slope of end-diastolic pressure volume relationship (EDPVR), that describes LV stiffness, has not been altered by exercise training. MCo, male control group; MEx, male exercised group; FCo, female control group; FEx, female exercised group. Values are means ± SEM. ^∗p < 0.05 vs. MCo, ^#p < 0.05 vs. FCo, p_i: interaction p-value of two-way analysis of variance (ANOVA).