[The dynamic circulatory reaction of pilots to the standard test].

The examination of cardiovascular system in pilots in the process of their training has shown that the Valsalva test can execute the function of a slight or strong irritant with further changes in hemodynamics, particularly in the frequency of systoles and arterial pressure. These changes are accompanied by the shifts of cardiac volume per minute from hypo to hyper reaction. A correlation was disclosed between the reaction in the frequency of systoles and cardiac volume per minute which can be studied from the point of view of adaptation of blood circulation system to the factors of physical loads.

[Nature of the regulation of blood circulation in pilots].

Dynamic observations over a group of pilots within a working week during three months have shown that blood pressure increases to meet the requirements via a higher cardiac output. When stresses grow and fatigue sets in, the pattern of circulation regulation changes so that elevated blood pressure is maintained due to an increased peripheral resistance. Differential approach to the pattern of blood pressure regulation makes it possible to assess the degree of circulation adaptation to various work loads.

[Study of the variations in cardiovascular system indicators using the main component method].

The main component method was used to analyze measurements of cardiovascular parameters taken in 14 healthy operators at rest. The entire sample included 237 observations. Each observation was characterized by the deviation of heart rate, mean blood pressure and stroke volume from individual data points.

[Potential for modelling the hemodynamic effects of weightlessness by exposure to increased pressure].

Venous and arterial circulation was investigated by simulating cephalad blood shifts generated by an exposure of test subjects (n = 15) to lower body positive pressure (+25 mm Hg) and head-down tilts (at -8 degrees and -15 degrees). At LBPP and tilt -15 degrees arterial pressure increased by 5-15%. During tilt -8 degrees jugular vein blood filling increased by 8-94% in the course of the first 3 hrs and then decreased reaching the baseline (horizontal position) level.