Tolerance of +Gx by MIR 22 -- 27 main crew in space flights

Data on +Gx tolerance by 16 cosmonauts-members of the Mir 22-27 main crews in missions from 8 up to 380 days in duration are reported. All cosmonauts showed good tolerance of g-loads during insertion into orbit. Owing to the use of anti-g suit Centaur and water-salt supplements prior to deorbiting, tolerance of +Gx in the course of descent was satisfactory in the majority of the cosmonauts and low only in one person. As compared with short missions (8 to 21 days), strain of the physiological systems exposed to the deorbit +Gx loads following an extended period in microgravity (186 to 380 days) was greater and manifested by more often arrhythmias, hard breathing and speech, vestibulo-autonomous reactions, petechial hematomas into the back tegmentum, and more severe sinus tachycardia. As a rule, there were no symptoms indicative of poor g-tolerance (visual disorders etc.) which speaks for effectiveness of the anti-g measures in most of the cosmonauts. However, prognostically bad cardiac rhythm disturbances (multitude of single, group and systemic polytope ventricular extrasystoles) registered in one cosmonaut on the deorbit phase mean that efforts should be redoubled to improve countermeasures against the deconditioning of organism by microgravity, particularly the cardiac rhythm disturbances.