Pulmonary Circulation at Highlanders

The high-altitude pulmonary arterial hypertension is discovered approximately at 45.7 percent of permanent inhabitants of Tien-Shan and Pamir and at 6.8 percent it is complicated by right heart failure. To investigate the especialities of pulmonary circulation at highlanders with normal and elevated pulmonary arterial pressure we studied 61 residents of Tien-Shan, living at 2800-3200 meters above sea level. The subjects were apparently healthy male volunteers aged 16 to 50 years, who underwent right-sided heart catheterization. Levels of systolic pulmonary arterial pressure (systolic PPA ) (22.7 ± 3.38 mmHg) and mean PPA (14.5 ± 3.47 mmHg) at first group of highlanders were within the normal range, whereas the levels of pulmonary vascular resistance (PVR) were increased (220.7 ± 40.8 dyn/sec/cm-5, p<0.05). At highlanders of second group the levels of systolic PPA (34.7 ± 7.30 mmHg) and mean PPA (22.9 ± 7.50 mmHg) turned out to be higher than at highlanders of first group approximately of 53 and 58%. The levels of PVR were significantly higher (p<0.001) than at previous group. These findings suggest that among permanent high-altitude residents take place hidden form pulmonary arterial hypertension that consistent with our previous hypothesis that among highlanders there are individuals with normal and high sensitivity to exogenous hypoxia which reflect the changes of neurohumoral regulation of pulmonary circulation.