Pulmonary arterial hypertension (PAH)
- Group 1 – Elevation of pressure in the pulmonary arteries (idiopathic, hereditary, or toxin induced). A progressive disorder of primary pulmonary arterial vasculopathy characterized by a mean pulmonary arterial pressure > 25 mm Hg at rest or > 30 mm Hg during exercise. Examples include idiopathic PAH, hereditary PAH, and PAH due to connective tissue disease, HIV infection, portal hypertension, congenital heart disease, congenital abnormality (eg, cardiac, hepatic, extrahepatic), schistosomiasis, or drug use. Several genetic mutations may be implicated in the pathogenesis of PAH.
- Group 2 – Elevation of pressure in the pulmonary venous system due to left heart disease.
- Group 3 – Elevation of pressure in the pulmonary venous system due to lung disease or hypoxia.
- Group 4 – Chronic thromboembolic pulmonary hypertension.
- Group 5 – Pulmonary hypertension with unclear or multifactorial mechanisms.
PAH is sometimes associated with pulmonary artery aneurysm and, rarely, in long-standing cases, pulmonary artery dissection.
Multiple pulmonary metastases can be a cause of rapid-onset pulmonary hypertension.
Related topic: portopulmonary hypertension