Pulmonary Hypertension

Pulmonary hypertension (PH) is a syndrome characterized by elevated pulmonary artery pressures (PAPs) and is currently defined as a mean PAP of greater than 20 mm Hg on right heart catheterization. PH is classified into five groups: group 1 (pulmonary arterial hypertension [PAH]), group 2 (left heart disease), group 3 (lung disease and/or hypoxia), group 4 (related to pulmonary artery obstruction), and group 5 (related to unclear/multifactorial mechanisms). PAH is a rare condition that may be caused by such conditions as connective tissue disease, human immunodeficiency virus, portal hypertension, and methamphetamine use. PH usually presents with exertional dyspnea and fatigue, and transthoracic echocardiography is the screening test of choice. If there is a high suspicion for PH, right heart catheterization is mandatory to make the diagnosis and properly classify patients. Prognostic assessment is critical to determine proper treatment and includes laboratory biomarkers, echocardiography, cardiac magnetic resonance imaging, and exercise testing. Group 2 PH is the most common cause of PH in the developed world and may be related either to heart failure with preserved or reduction ejection fraction, as well as left-sided valvular heart disease. Group 5 PH is a heterogeneous group of disorders, including chronic hemolytic anemias, myeloproliferative disorders, metabolic (e.g., Gaucher disease) and systemic (e.g., sarcoidosis) diseases, chronic renal failure, fibrosing mediastinitis, and complex congenital heart disease. Proper classification is essential because PAH-specific treatment is recommended against in group 2 and 5 PH.