Adaptive Response of the Heart and Peripheral Vasculature on Single Physical Exercises in Experiment

Abstract

The aim of the investigation was to assess the parameters of urgent adaptation of the heart and peripheral vasculature to single physical exercises to determine an individually safe value of motor activity.Materials and Methods. The experiments were carried out on 84 mongrel male dogs. Physical exercises were modeled in laboratory environment by treadmill run. Three types of exercises were used in the experiment: mild, optimal and excessive. Exercise duration was controlled individually, for each animal considering cardio-respiratory system state by heart rate. Cardiac work was assessed by echocardiography and electrocardiography, peripheral circulation -by hindleg rheovasogram.Results. Experimental findings indicate significant alterations in cardiac conducting system under single physical exercises. A single mild exercise causes the increase of minute blood output due to heart rate increase. Hind leg muscular blood filling decreases. An optimal exercise results in minute blood output increase due to stroke blood volume growth. Myocardial contractility increases. Muscular blood filling rises. In excessive load increased stroke output is accompanied by left ventricular cavity dilatation. Pulse volume decreases, peripheral vasculature elasticity reduces, and hind leg muscular venous outflow gets worse.Conclusion. urgent adaptation of the heart and peripheral vasculature in single physical exercises shows as a marked response to a simulated factor. The technique to assess the body adaptation considering cardiovascular system condition enables to calculate individual volume of physical activity and develop recommendations for it to be used efficiently in medicine.

Spatial Organization Types of Sinoatrial Node in Dogs with Different Body Functional Reserve Levels

“…According to the organization level, there can be distinguished cell, tissue, organ and systemic reserves, as well as the reserves of the whole body. Physiological studies on urgent adaptation of the heart to motor loads [1,[17][18][19][20][21][22][23] evidence high variability of adaptive responses that explains the necessity for studying SAN structural peculiarities with due account of a functional body reserve level.…”