The regional distribution of pulmonary blood flow in normal high altitude dwellers at 3650 m (12,200 ft) and in chronic mountain sickness

Abstract

Summary. Simultaneous isotope dilutaon curves were recorded from the right upper (QRUZ) and right lung zones (QRLZ) by Surface scanning in the sitting and recumbent positions in 15 normal high altitude born males and 3 male newcomers, using 10 µCi of 131IHSA as a bolus injection into the right ventricle. Similar information was also obtained at sea level from 5 normal males and at altitude from 122 patients thought to suffer from chronic mountain sickness (CMS). The mean percent distribution of total pulmonary blood flow (Q) to RUZ and RLS in the 2 body postures were as follows: The observations indicate: (1) that in the vertical position RUZ in males receives about 17% of Q regardless of altitude and elevation in mean pulmonary artery pressure (MPAP) in HAD of 7.7 mmHg above that extant at sea level. (2) Recumbency at high altitude showed QCRUZ also to be lower tan at sea level. (3) Elevation in MPAP at altitude has no significant effect on changing the sea level distribution pattern of pulmonary blood flow. (4) CMS shows the largest reduction in RUZ perfusion in both postures and in the presence of severe pulmonary hypertension.