Primary Pulmonary Hypertension

Primary Pulmonary Hypertension -Primary pulmonary hypertension (PPH) is a rare disease characterized by elevated pulmonary artery pressure with no apparent cause. PPH is also termed precapillary pulmonary hypertension or, more recently, idiopathic pulmonary arterial hypertension (IPAH). The term IPAH is now the preferred term for pulmonary arterial hypertension of unknown etiology; thus, IPAH represents pulmonary vascular disease with a spectrum of clinical presentations.

Dresdale and colleagues first reported a hemodynamic account of IPAH in 1951.[1] However, the pathophysiology of IPAH remains poorly understood. At least 15-20% of patients previously thought to have IPAH actually have a familial form of PAH involving at least one genetic defect, which has only recently been characterized (see Pathophysiology).

Cardiac catheterization is the criterion standard test to definitively confirm any form of PAH, including IPAH. However, a thorough workup includes a range of tests to exclude all reasonable causes of secondary pulmonary hypertension (see Workup).

Until recently, calcium channel blockers (CCBs) had been the most widely used class of drugs for IPAH. Patients with IPAH in whom CCBs are contraindicated, ineffective, or poorly tolerated may respond to long-term vasodilator therapy (see Treatment and Management).

Treating IPAH requires significant knowledge of and exposure to the available therapies for IPAH and their potential complications. Because IPAH is relatively rare, management is best left to expert personnel at centers with regular exposure to these patients (see Treatment and Management).