A second hit? Pulmonary arterial hypertension, mutation, and exposure to prescription amphetamines.

The second hit hypothesis in pulmonary hypertension refers to the development of pulmonary vascular disease in individuals at risk, after an additional exposure or "hit" to factors with potential injury to the pulmonary circulation, such as drugs or toxins. We here present a case of severe pulmonary hypertension diagnosed during the third trimester of pregnancy, in a patient with familial history of pulmonary hypertension, found to have a heterozygous mutation in the gene, who also had chronic exposure to prescription amphetamines. We hypothesize that exposure to prescription amphetamines could act as a second hit of pulmonary vascular injury in individuals at risk of pulmonary vascular disease.