抄録
In order to evaluate the efficacy of Ch'an Su containing drug in improvement of acutemountain sickness, the effect on the cardiac output (CO) was examined in 19 experiments with five healthy, 21 to 29 years old, males during exposure to 7, 000 maltitude conditions simulated by a decompression chamber. The subjects were also loaded by exercise with bicycle ergometer during the stay. Five minutes after exercise the single oral administration of the drug (5 mg) or its placebo was taken, then the impedance changes of chest wall, by which the stroke volume (SV) was estimated, and the heart rate (HR) were recorded every 3 or 5 minutes- during the subsequent 20 minutes. CO could be obtained as the product of SV and HR. Although there were considerably large individual differences, the average SV and CO at the 6, 10 and 15 post-drug minutes demonstrated statistically significant increase in comparison with those obtained from the placebo experiments. Further, the data obtained in these increasing periods gave the correlation coefficient of 0.891 for SV to CO relation, while only 0.416 for HR to CO, showing that the CO increase is highly dependent to that of SV. The results suggested that drug acts effectively, and rapidly as well, to improve the cardiac muscle activity against to the hypoxic impairment experienced under extreme high altitude conditions.
