Figure 5.
Increases in indexed right ventricle (RV) contractility in response to pulmonary artery banding (PAB) depend on sex and ovariectomy (OVX), but mechanoenergetic cost to pump blood does not. A and B: effects of sex and OVX on indexed arterial elastance (iEa; A) and indexed end-systolic elastance (iEes; B) are shown for each group. n = 8–10 animals per group. Values are presented as means ± SE. P < 0.05 for *PAB vs. respective Sham, †female (intact or OVX) vs. male, and ‡OVX vs. intact female (2-way ANOVA with Tukey’s honestly significant difference (HSD) multiple comparison correction). C: model-based estimation of RV mechanoenergetic cost to pump blood [change in pressure-volume area (PVA) per unit change in stroke volume (SV)] as a function of iEa and iEes. The group centroid is located at the group average (iEa, iEes); the boundary is defined by the SE. PAB groups are significantly different from Sham (P < 0.05) by multivariate analysis of variance (MANOVA) with Tukey’s HSD post hoc test. D: representative pressure-volume loops recorded during transient vena cava occlusion, from which iEa and iEes are calculated for each group.