[Comparative characteristics of central hemodynamics and blood redistribution in active and passive orthostatic tests].

Typological characteristics of central and peripheral (legs and viscera) circulation were identified in 90 clinically healthy people exposed to active and passive orthostatic tests. The following three hemodynamic states were distinguished: hypokinetic, hyperkinetic, and intermediate types of circulation. As compared to the passive tests, in the active states cardiac output decreased, leg blood flow increased, and viscera blood flow decreased. At the stage of stabilized hemodynamics inotropic cardiac stimulation was predominant during active orthostatic tests and chronotropic cardiac stimulation was predominant during passive orthostatic tests. In the former tests changes in cardiac output and blood redistribution between leg and viscera circulations were more distinct. Mechanisms of hemodynamic changes are discussed.