The electronic medical record for each patient with echocardiographically assessed moderate or severe PH (N=340) was analyzed to identify patients undergoing specific test(s) that are important for establishing PH disease etiology as well as disease severity. PFT, pulmonary function test (spirometry only); DLCO, lung diffusion capacity to carbon monoxide; RHC, right heart catheterization; CT-A, thoracic computed tomographic angiography; V/Q, ventilation/perfusion.