Gravitation importance in the evolution of prehypertension.

Gravitation plays the important role in a pathogeny of the essential hypertension (EH). Modifications of hydrostatic pressure during body position changes, related to gravitational action, produce the significant hemodynamics shifts. Discordance of the orthostatic hemodynamics reactions with gravitational action can lead to orthostatic hypotension or proceed without any clinical signs during increased hemodynamic respond. Absence of physiological circulatory orthostatic responses, possibly, is very initial sign of EH development. This assumption is confirmed by the outcomes of the prospective studies in whose have been shown that EH more often develops in patients with normal arterial pressure accompanied by circulatory orthostatic disorders. The prehypertension (PH) became the studies subject only after publication of the report 7 of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (7 JNC). Its diagnosis based on blood pressure (BP) measurement. According to the report, the PH is a risk factor of EH development. Peculiarities of life development on the Earth, phylogenetic features of cardiovascular system evolution and physical effects of gravitational action, allow us to advance a hypothesis that the PH is the beginning of EH pathogenesis. One of the diagnostic methods may be the system hemodynamics study at passive head-up tilt.