Changes in cardiohemodynamic parameters,cardiointervalography, and microcirculation observed in local cold test in young men born in northern regions

The cardiohemodynamic and blood microcirculation parameters at rest and under local cold exposure in young male subjects have been estimated. It has been found that the subjects with the initially low velocity of erythrocytes (blood flow) in their nail bed capillaries have higher blood pressure, stroke volume, cardiac output, and cardiac index, which proves that these subjects have the hyperkinetic type of blood flow with the pronounced hypertensive reaction. At the same time, the shift of heart rate variability values under the cold exposure indicates that the activation of the sympathetic autonomic nervous system is more statistically significant than that in those subjects who originally had a higher velocity of erythrocytes. In the subjects of this group, no changes were observed in either heart rate autonomic regulation or index of tension under the local cold exposure, which proved that these subjects had the enhanced functional reserves of the cardiovascular system and autonomic regulation. They also had a fairly pronounced reactivity of the parameters of systemic hemodynamics, which manifested itself in changes in their blood filling parameters against the background of decrease in total peripheral vascular resistance and coefficient of integral tonicity.