Fig. 2. A linear relationship between pulmonary artery diastolic-pulmonary capillary wedge pressure (PAD-PCWP) gradient and the ratio of pulmonary venous resistance/total pulmonary vascular resistance (PvR/TPVR ratio) as combined data. PvR/TPVR ratio = 0.0357 × PAD-PCWP gradient + 0.365. Open triangles represent data at low pulmonary blood volume (PBV; r 2= 0.798, P < 0.0001), and closed triangles represent data at high PBV (r 2= 0.749, P < 0.0001).
