ИССЛЕДОВАНИЕ КРОВОТОКА ЧЕРЕЗ МИТРАЛЬНЫЙ КЛАПАН СЕРДЦА ЧЕЛОВЕКА С УЧЕТОМ КАРДИОТИПА И В СВЯЗИ С ФУНКЦИОНАЛЬНЫМИ НАГРУЗКАМИ

Abstract

Background. Studies of the cardiovascular system originated in the 60s of the last century, including the work of P. O. Astrand, according to which, with extreme functional loads (FL), accompanied by maximum heart rate, stroke volume (SV) decreases. The study of the mechanism of this effect requires the use of a complex of electro- and echocardiographic methods. The purpose of this work is to determine the dependence of electrocardiographic and echocardiographic parameters on cardiotype and physical activity. Material and methods. The study involved 30 males aged 18 to 32 years. Based on the heart rate indicators in the controls, which were determined by the electrocardiogram (ECG), the participants were divided into three groups: bradycardia (9 people) – 60 or less beats/min, normocardia (9 people) – 61-80 beats/min, tachycardia (12 people) – more than 80 beats/min. The indicators were taken in the standing position (controls) and after exercise (experimental group) – squats (according to Martine) in combination with an arbitrary cessation of external respiration on inspiration (according to Stange) as long as one could. Results. The lower was the heart rate, the greater was the total volume of the transmitral blood flow. With an increase in electrical diastole (TR segment), myocardial excitability decreased. With FL, this dependence persisted. The duration of the PQ ECG element did not differ between groups and depending on the effect of physical activity. But the volumes of blood passing during the duration of PQ varied markedly. In all three groups, they increased, which was probably due to the increasing power of myocardial contraction during atrial systole. Conclusions. In terms of absolute value, the volume of blood flow through the mitral valve of the human heart is increased in bradycardia and reduced in tachycardia. In terms of relative value, in the series from bradycardia to tachycardia and from conditions without exercise to conditions with the use of exercise, the proportion of flow A increases. The share of flow E decreases accordingly.