Current or prior chronic vasodilator therapy for pulmonary hypertension

Known collagen vascular disease

HIV infection: Based on self-report /historical diagnosis

Portal hypertension

Prior anorexigen use

History of corrected or uncorrected intracardiac shunt

Prior pulmonary embolism

Sickle cell disease

Left ventricular dysfunction (ejection fraction \< 45%)

Moderate or severe mitral regurgitation

Moderate aortic stenosis (mean gradient \> 25 mm Hg)

Symptomatic, non-revascularized coronary artery disease

Evidence of parenchymal lung disease with a TLC \< 70% and an FEV1 \< 65% of predicted with pulmonary function testing

Pregnancy - Serum pregnancy test for women of child bearing potential, if cardiac catheterization is needed

Unable to provide informed consent

Symptomatic Pulmonary Arterial Hypertension After Mitral Valve Surgery