Figure 1. The relationship between lung diffusing capacity for carbon monoxide (DL_CO, top), alveolar‐capillary membrane conductance (Dm, middle), and pulmonary capillary blood volume (Vc, bottom) and (A) mean pulmonary artery pressure (PAPm) and (B) mean pulmonary capillary wedge pressure (PCWPm) measured at rest (circles), a fixed work rate (20 W, squares), and symptom‐limited maximal exercise (triangles).

Mean and standard error are shown for each stage. HFpEF indicates heart failure with preserved ejection fraction.