[Seven-day dry immersion: relations between water-electrolyte and cardiovascular responses].

The paper presents the results of the experiment with 7-day dry immersion. Eight healthy men were studied before, during and after exposure. It is shown that the primary response involves hemodynamic and water-electrolyte changes. The mechanisms of cardiovascular adaptation to immersion conditions are revealed. In particular, some electrophysiological shifts in propagation of myocardial excitation are found, leading to increase in "myocardium" index, estimated by analysis of natural small oscillations in the amplitude of the PQRST complex with dispersion ECG mapping. Revealed significant reduction of functional reserves of the cardiovascular regulatory mechanisms in the process of adaptation to dry immersion is of great practical importance. The results suggest that water-electrolyte shifts induced by dry immersion are the basis and the first phase of the further changes in autonomic regulation and myocardial functional state.