Pulmonary hypertension

Pulmonary hypertension
Pulmonary hypertension is defined as a mean pulmonary arterial pressure ? 25 mm Hg at rest and a normal (? 15 mm Hg) pulmonary artery occlusion pressure (pulmonary capillary wedge pressure) .
Etiology
Many conditions and drugs cause pulmonary hypertension. The most common overall causes of pulmonary hypertension are
• Left heart failure, including diastolic dysfunction
• Parenchymal lung disease with hypoxia
• Miscellaneous: Sleep apnea, connective tissue disorders, and recurrent pulmonary embolism
Pulmonary hypertension is currently classified into 5 groups
A small number of cases of pulmonary arterial hypertension (PAH) occur sporadically, unrelated to any identifiable disorder; these cases are termed idiopathic pulmonary arterial hypertension. Hereditary forms of PAH (autosomal dominant with incomplete penetrance) have been identified.
Certain drugs and toxins are risk factors for PAH. Those definitely associated with PAH are appetite suppressants (fenfluramine, dexfenfluramine, aminorex), toxic rapeseed oil, and benfluorex. SSRIs taken by pregnant women are a risk for development of persistent pulmonary hypertension of the newborn (PPHN). Drugs that are likely associated with PAH are amphetamines, methamphetamines, L-tryptophan, and dasatinib .
Patients with hereditary causes of hemolytic anemia, such as sickle cell disease, are at high risk of developing pulmonary hypertension due to chronic hemolysis causing NO consumption.