Clinical, Physiological, and Pathological Considerations in Patients With Idiopathic Pulmonary Hypertension

Cases of idiopathic pulmonary hypertension are uncommon. Paul Wood (1950) found 6 examples among 233 unselected patients suspected of having congenital heart disease, 152 of whom were catheterized. Dresdale et al. (1951) encountered four cases and mentioned that ten cases of pulmonary hypertension without demonstrable cause in which cardiac catheterization had been performed had been reported.