[Hemodynamic reactions to modified orthostatic test in persons with different +Gz tolerance].

Hemodynamic responses to the passive and modified orthostatic tests were investigated in 27 low and 13 high +Gz susceptibility individuals. The modified orthostatic test included 5 min head-down tilt (-30 degrees) and head-up tilt (78 degrees) with occlusion cuffs (50 mm Hg and 100 mm Hg) applied to the upper third of the hip. Analysis of typological reactions in low and high +Gz susceptibility individuals revealed no significant differences in their tolerance to the above tests. It was found that during the 1st minute of the modified orthostatic test with 100 mm Hg pressure in the occlusion cuffs heart rate was lower and systolic blood volume was higher (p less than 0.05) than during the passive test. Differences in these parameters disappeared by the 10th minute of exposure. During the modified orthostatic test with 50 mm Hg pressure in the occlusion cuffs these parameters did not show statistically significant differences.