Pulmonary Pressure, Cardiac Output, and Arterial Oxygen Saturation during Exercise at High Altitude and at Sea Level

Abstract

The response elicited by exercise on pulmonary pressure, cardiac output, and arterial oxygen saturation in 35 lifetime residents of high altitude has been studied at high altitude (14,900 feet above sea level), and 22 residents of low altitude have been studied at sea level. A procedure combining cardiac catheterization, arterial cannulation, and spirometry was carried out. The exercise was moderate and was performed in supine position using a bicycle ergometer, the work load being 300 kg-m/min/m,2 and the average increase of the oxygen uptake being 4.7 times at sea level and 4.8 times at high altitude. Both at sea level and at high altitude the cardiac output augmented during exercise proportionally to the increase in oxygen uptake, and thus followed the pattern of response described by other authors. The cardiac output as well as the oxygen intake, for the magnitude of exertion performed in this study, was almost the same at sea level and at high altitude. The cardiac output rose during exercise almost ...