Pulmonary arterial elastance for estimating right ventricular afterload in systolic heart failure.

Assessment of right ventricular afterload in systolic heart failure seems mandatory as it plays an important role in predicting outcome. The purpose of this study is to estimate pulmonary vascular elastance as a reliable surrogate for right ventricular afterload in systolic heart failure. Forty-two patients with systolic heart failure (ejection fraction <35%) were studied by right heart catheterization. Pulmonary arterial elastance was calculated with three methods: Ea(PV) = (end-systolic pulmonary arterial pressure)/stroke volume; Ea*(PV) = (mean pulmonary arterial pressure - pulmonary capillary wedge pressure)/stroke volume; and PPSV = pulmonary arterial pulse pressure (systolic - diastolic)/stroke volume. These measures were compared with pulmonary vascular resistance ([mean pulmonary arterial pressure - pulmonary capillary wedge pressure]/CO). All estimates of pulmonary vascular elastance were significantly correlated with pulmonary vascular resistance (r=0.772, 0.569, and 0.935 for Ea(PV), Ea*(PV), and PPSV, respectively; P <.001). Pulmonary vascular elastance can easily be estimated by routine right heart catheterization in systolic heart failure and seems promising in assessment of right ventricular afterload.