[Change in the hemodynamics and phase structure of the cardiac cycle in the crew of the 2d "Saliut-4" expedition].

: Medical examinations of the Salyut-4 crewmembers included bicycle ergometry tests. During the tests the heart rate and the time intervals of the left ventricle were measured. On the 46th flight day the arterial pressure, cardiac output and peripheral resistance were also determined. In the course of the 63-day flight responses to the 5 min workload of 2100-2200 kgm did not differ essentially from the preflight level, and did not increase with the flight time. Circulation changes noted in zero-g and upon return to I g were similar and can be accounted for by a reduction of the circulating blood volume. Inflight during the first minutes after the workload more marked changes in the cardiac output and cycle were detected. This can be attributed to a relatively stronger effect of blood pooling in working muscles on the venous return of the blood. On the 3rd postflight day the arterial pressure and the velocity of the aortal propagation of the pulse wave were higher.