Buderer M C, Rummel J A, Michel E L, Mauldin D G, Sawin C F
Aviat Space Environ Med. 1976 Apr;47(4):365-72.
Cardiac output was measured during preflight and postflight exercise-stress tests on the Skylab astronauts. In the postflight tests immediately following the 28-, 59-, and 84-d earth orbital missions, the astronauts exhibited an approximate 30% decrease in cardiac output coupled with an approximate 50% decrease in cardiac stroke volume during exercise. These changes were accompanied by elevated heart rates and significant (p less than 0.01) increases in total systemic peripheral vascular resistance. Mean arterial pressure was unchanged. The hemodynamic alterations were transient in that all parameters returned to normal preflight values within 30 d of the end of the orbital period. Duration of the zero-G exposure did not appear to influence either the magnitude of the hemodynamic changes or the time-course of their return to normal. These results are discussed in relation to other cardiovascular findings and possible mechanisms responsible for the observations are outlined.
在“天空实验室”宇航员的飞行前和飞行后运动应激测试期间测量了心输出量。在28天、59天和84天地球轨道任务后的飞行后测试中，宇航员在运动期间的心输出量下降了约30%，同时心搏量下降了约50%。这些变化伴随着心率升高和全身总外周血管阻力显著增加（p小于0.01）。平均动脉压未改变。血液动力学改变是短暂的，因为在轨道期结束后的30天内所有参数都恢复到了飞行前的正常水平。失重暴露的持续时间似乎既不影响血液动力学变化的幅度，也不影响其恢复正常的时间进程。本文结合其他心血管研究结果对这些结果进行了讨论，并概述了导致这些观察结果的可能机制。
