Insights by Peruvian scientists into the pathogenesis of human chronic hypoxic pulmonary hypertension.

Pulmonary hypertension had long been suspected in high-altitude natives of the Andes. However, it remained for a team of Peruvian scientists led by Dante Penaloza to provide not only the first clear evidence that humans living at high altitude did indeed have chronic, and occasionally severe, pulmonary hypertension, but more importantly, that this was a consequence of structural changes in the pulmonary vascular bed. Novel histological findings by one of the team, Javier Arias-Stella, indicated that hypoxia-induced thickening of the pulmonary arteriolar walls was the primary cause of the elevated pressure. Because the hypertension was not promptly reversed by vasodilators (oxygen inhalation or acetylcholine infusion), they found it differed from acute hypoxic pulmonary vasoconstriction. The team's other novel findings included a delay in the normal fall in pulmonary vascular resistance after birth and, in adults, a lack of vasodilation with muscular exercise. Furthermore, the altitude-related pulmonary hypertension resolved over time at sea level.