[Certain hemodynamic indicators during rest and after intensive physical exercise at high altitude].
For 5 years 364 normal males, aged 19--25, were studied at the altitude of 3800--4200 m, along with local inhabitants of the mountain region; the hemodynamic shifts and arterial blood oxygenation were studied with the base metabolism conditions preserved both at rest, and after intensive physical exercises performed according to the step-test method with the maximum tempo of the work (cardiological motion test, WHO, 1967). The initial reaction of the cardiovascular system to the high altitude conditions manifested itself in an increased stroke volume and cardiac output, of the volume speed of blood ejection, of the cardiac index in a decrease of the total peripheral resistance and oxygen saturation of the arterial blood. This reaction was interpreted as a compensatory one. In the course of acclimatizing, the cardiac output and the pulse amplitude of the arterial pressure gradually decreased, and the total peripheral resistance increased. These hemodynamic changes must be of an adaptative nature. The maximum physical workload caused a distinct intensification of the circulatory reactions, especially in those living for considerable periods of time at high altitude and in local inhabitants. The general state of the examined remained good. Hence, these persons have a considerable reserve of functional capacities of their cardiovascular system, and can perform hard muscle work at high altitude. Individuals staying at high altitude for only short periods of time react to intensive physical workloads by a less distinct intensification of the contractile capacity of the heart and by a sharp decrease of blood oxygenation, considerable acceleration of the heart rate and respiration rate, as well as by a deterioriation of their general state. Such muscular efforts cause overloading of the heart only in persons with a short-term acclimatizing.
D000064:Acclimatization; D000328:Adult; D000531:Altitude; D002302:Cardiac Output; D002306:Cardiac Volume; D006439:Hemodynamics; D006801:Humans; D008297:Male; D009200:Myocardial Contraction; D010100:Oxygen / Q000097:blood; D005082:Physical Exertion; D012146:Rest; D014655:Vascular Resistance
D010100:Oxygen
Nekotorye gemodinamicheskie pokazateli v pokoe i posle intensivnykh fizicheskikh nagruzok v usloviiakh vysokogor'ia