Combined PDE-5 and ET
inhibition improves RV function in SU-Hx rats. (A) Invasive pressure-volume analyses were performed at study endpoint. Representative RV pressure-volume loops are shown. The increase in RV end-systolic (B) and end-diastolic pressure (C) in SU-Hx rats was completely blocked by combined TAD/AMB treatment. (D) Pulmonary vascular resistance, calculated based on cardiac output, was lowered by TAD/AMB. (E) RV systolic function, based on ejection fraction (EF), was normalized by TAD/AMB. (F) RV cardiac output trended lower in SU-Hx rats, although the decrease was not statistically significant. *P < 0.05 vs. normoxia.