Phosphodiesterase Type 5 Inhibitors for Pulmonary Arterial Hypertension.

A 46-year-old woman presents with progressive exertional dyspnea and recurrent exertional syncope. Her jugular venous pressure is 16 cm of water, and moderate peripheral edema is noted. Auscultation reveals a pronounced pulmonic component of the second heart sound and a grade 2/6 holosystolic murmur of tricuspid regurgitation. Echocardiography shows moderate right ventricular and right atrial enlargement, right ventricular systolic dysfunction, and an estimated right ventricular systolic pressure of 100 mm Hg. Cardiac catheterization reveals a mean right atrial pressure of 13 mm Hg, a pulmonary-artery pressure of 80/40 mm Hg (mean, 58), a mean pulmonary-capillary wedge pressure of 10 mm Hg, and a cardiac output of 5 liters per minute. The results of additional studies to detect causes of secondary pulmonary hypertension or associated conditions are unremarkable, and she receives a diagnosis of idiopathic pulmonary arterial hypertension. Her pulmonary- artery pressure does not decrease in response to inhaled nitric oxide. Therapy with sildenafil is recommended.