Figure 4.

As compared with individuals with isolated post-capillary pulmonary hypertension and controls, individuals with combined post- and pre-capillary pulmonary hypertension displayed lower arterial pO₂ with exercise despite similar alveolar O₂ tension (A, B). Arterial pO₂ during exercise decreased with greater increases in extravascular lung water during exercise (C) and higher resting pulmonary vascular resistance (D). PA, pulmonary artery; PAP, pulmonary artery pressure; RAP, right atrial pressure; PAWP, pulmonary artery wedge pressure; RV, right ventricular; s′, systolic tissue doppler velocity; Q_T, cardiac output; CpcPH, combined post-and pre-capillary pulmonary hypertension; IpcPH, isolated post-capillary pulmonary hypertension; VO₂, oxygen consumption; DO₂, oxygen delivery. ‘r’ determined by Pearson’s correlation analysis. *P < 0.05 vs. controls. †P < 0.05 vs. IpcPH groups.