[Regional hemodynamic changes following space flights lasting up to 8 days]

Before and after space missions of up to 8 days in duration 14 cosmonauts were exposed to rheographic examinations to measure the pulse blood filling, tone and elasticity of cerebral vessels (in the frontal-mastoidal and bimastoidal leads), right lung and right leg vessels during tilt tests. Postflight examinations demonstrated distinct changes in the cerebral, pulmonary and peripheral circulation, thus indicating cardiovascular deconditioning. The greatest changes were seen in the tone of arteries, arterioles, and veins of the brain hemispheres, vertebro-basilar system and the leg. The changes were reversible, requiring no special correction. The changes in different vascular compartments returned to normal in a nonuniform manner: hemodynamic parameters of the lung and leg returned to the preflight level by R+3, whereas those of the brain by R+14.