Increases in hemodynamic energy input in response to pulmonary artery banding (PAB) depend on sex and ovariectomy (OVX), but their ratio (mechanical efficiency) does not. Effects of sex and OVX for pressure-volume area scaled to body weight (iPVA; A), external work scaled to body weight (iEW; B), and mechanical efficiency (iEW/iPVA; C) are shown. 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 multiple comparison correction).