FEATURES OF THE STRUCTURE OF THE CARDIAC CYCLE IN RECRUITS TRAINING CENTER OF THE NAVY IN THE ARCTIC ZONE

Abstract

Objective: to identify the features of the structure of the cardiac cycle among recruits of the Navy training center, who arrived from different climatic and geographical regions of the Russian Federation in the Arctic zone. Two groups of servicemen of 37 people were formed: the first group consisted of recruits from the southern regions of the Russian Federation, and the second — natives of the northern region. Each soldier was examined monthly for 5 months. To study the structure of the cardiac cycle, polycardiography was used, which included simultaneous recording of an electrocardiogram (ECG), phonocardiogram (PCG) and sphygmogram (SG) of the carotid artery. It was established that the duration of the asynchronous reduction (AS) phase for servicemen from the southern regions during the 5-month observation period only tended to decrease from 0,053±0,004 to 0,044±0,004 s, and starting from 3 months. In the group of servicemen-northerners, the duration of the AU phase during the observation period was statistically significantly reduced from 0,055±0,003 to 0,040±0,004 s, and in months 3, 4, and 5 from 22% to 27% (p<0,05). The stress period (T) in the systole of the ventricles in military personnel from the southern regions also remained almost unchanged, while in the military northerners it was statistically significantly reduced from 0,085±0,002 to 0,080±0,001 s, as well as the duration of the total (electromechanical) systole (So) from 0,372±0,004 to 0,358±0,006 s. Thus, when training at the Navy training center located in the AZ, for recruits-northerners the duration of the AC phase decreases after 2 months, and after 4 months the time T and the duration of So decrease, indicating the beginning of a more efficient work of the myocardium. For recruits from the southern regions of the Russian Federation, by the end of their studies, there is only a slight tendency towards a decrease in the AU phase, which indicates a less efficient work of the myocardium in comparison with the group of northerners.