Contrasting cardiopulmonary responses to incremental exercise in patients with schistosomiasis-associated and idiopathic pulmonary arterial hypertension with similar resting hemodynamic impairment.

It has been reported that schistosomiasis-associated PAH (Sch-PAH) has a more benign clinical course compared with idiopathic PAH (IPAH). We therefore hypothesized that Sch-PAH subjects would present with less impaired cardiopulmonary and metabolic responses to exercise than IPAH patients, even with similar resting pulmonary hemodynamic abnormalities. The aim of this study was to contrast physiologic responses to incremental exercise on cycle ergometer between subjects with Sch-PAH and IPAH.