Figure 1.

Right ventricular (RV) pressure–volume loops at decreasing venous return in a patient with a) systemic sclerosis-associated pulmonary arterial hypertension (PAH) and b) idiopathic PAH. The mean pulmonary artery pressure of both patients was similar. The slope of linearised maximum elastance pressure–volume relationship was higher in the patient with IPAH, indicating higher contractility. Note the maximum RV pressure close to the pressure at maximum elastance in both patients. Reproduced from [14] with permission from the publisher.