Hemodynamic aspects of compensatory reactions of human cardiovascular system in the conditions of postural loads

Abstract

Introduction. The aim of the work was to study the features of central hemodynamic reactions and regulatory mechanisms in persons with hypo- and hyperkinetic blood circulation and different physical status under postural loads. Methods. The parameters of central hemodynamics and spectral characteristics of the heart rhythm were applied. Healthy men aged 18-21 years with different physical status were involved. Results. Significant differences were established in adaptive reactions of people with different types of blood circulation and physical status in the conditions of postural loads. Adaptive reactions of central hemodynamics in individuals with the hyperkinetic compared with hypokinetic type of blood circulation in the head-up-tilt position were characterized by more intracardiac and vascular tension and less involvement of the higher vegetative centres. The surveyed persons with the hypokinetic type of blood circulation under these conditions were characterized by lower vascular activation and greater involvement of systemic extracardiac regulation mechanisms. The compensatory reactions of the cardiovascular system in the head-down-tilt position of people with the hypokinetic type of blood circulation, especially athletes, were characterized by a lower activity of the contractile function of the heart and the participation of extracardiac mechanisms of regulation, and those with the hyperkinetic type - by more prominent switching of the higher regulatory centres of the central nervous system and humoral nervous centres on the background of the tension of self-regulation processes. Conclusions. The revealed features of compensatory reactions of the cardiovascular system may be useful in the field of clinical and sports medicine, and physical rehabilitation.