UDC

612.172.2:612.172.4:612.176

Authors

Nadezhda G. Russkikh*, Lev I. Irzhak*
*Syktyvkar State University named after Pitirim Sorokin (Syktyvkar, Russian Federation)

Abstract

This paper studied electrocardiograms (ECG) of healthy young men aged 18–19 years at rest and during a mental test. The work aimed to examine the duration of the PP, РT, and PQ intervals and the TP segment at rest and in response to a mental test. The research involved 15 first-year students of Syktyvkar State University named after Pitirim Sorokin. Their body length (cm) and weight (kg) were measured and their heart rate was palpated for 60 seconds. Using the VNS-ritm device (Neurosoft, Russia), 50 ECG cardiac cycles were recorded in lead II at rest (seated position) and during the mental test (mental counting from 100 to 1 for one minute). Within one minute, the heart rate increased by an average of 41 %, the РР interval decreased by 30 %, the duration of the РT and PQ intervals remained at the initial level, although the share of the РT interval in the cardiac cycle increased by 33 %. The duration of the TP segment almost halved. Thus, the lowest variability in this experiment was observed in the PT and PQ intervals, while the highest, in the TP segment. It was revealed that the higher the heart rate as a result of the mental test, the bigger the share of the atrioventricular complex (PT) and the smaller the share of the electrical diastole (TP) in the total duration of the PP interval. The degree of the increase in heart rate and shortening of the ECG elements’ duration depends on their values at rest.

Keywords

electrocardiogram, electrocardiogram intervals, heart rate, mental test, heart rate variability, young men aged 18–19 years

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