Heart Rate Structure Research Articles

ХВИЛЬОВА СТРУКТУРА СЕРЦЕВОГО РИТМУ ПРИ ОРТОПРОБІ У ОСІБ З РІЗНИМ РІВНЕМ ВЕГЕТАТИВНОГО ТОНУСУ

Introduction. It is known that there are typological features among healthy young people according to the level of autonomic tone. Accordingly, there are groups of sympatho-, normo- and vagotonics. Work has been carried out to study the influence of the initial level of autonomic tone on thereactions of the cardiovascular system in respiratory hypocapnia, pulsed ophthalmic photostimulation, in different phases of the biological cycle for women. However, there is no work on the analysis of changes in the wave structure of heart rate depending on the initial level of autonomic tone. Purpose. The aim was to determine the features of the wave structure of the heart rhythm during orthoprobe for healthy young men with different levels of tone of the autonomic nervous system at rest. Methods. Measurements were performed in conditions close to the main exchange. 117 healthy young men aged 18-23 years were examined in compliance with the requirements of bioethics. Three main spectral components were analyzed in the tRR spectrum: HF (0.15-0.4 Hz) LF (0.04-0.15Hz); VLF (0-0.04 Hz); TP (0-0.4 Hz). The amplitude of the largest peak of the tRR spectrogram in the frequency range 0.04-0.15 Hz (aLF) and its frequency (tLF) were calculated. Normalized median spectrograms of tRR oscillations were constructed.Results.A significant decrease in HF was observed in individuals of all three groups during orthoprobe. The median reactivity of reactivity was -67.3%, -77.5%, -77.9% for groups I, II and III, respectively. There were no differences between the groups due to the reactivity of this indicator. The reactivity of LF to changes in body position for sympathotonics was significantly different.The frequency of the maximum peak of the spectrogram in the range of low often resting heart rate did not differ between groups. This indicator probably decreased during orthoprobe in groups IIand III. It was found that the wave has two peaks in the vertical position in persons with different baseline levels of autonomic tone for vagotonics and normotonics in the frequency range from 0.04 to0.15 Hz. Originality. Differences in the reactivity of heart rate waves to orthoprobe for healthy young men with different baseline levels of autonomic tone were detected for the first time. Conclusions. The greatest differences in changes in the wave structure of the heart rhythm during orthoprobe for persons with different baseline levels of autonomic tone are manifested in therange of low heart rate. Spectrum reduction reactions in this range were predominant for sympathotonics. The reactions of increasing LF and the amplitude of the maximum peak of the spectrogram were predominant for normo- and parasympathotonics. It was found that the wave has two peaks in the vertical position in persons with different baseline levels of autonomic tone for vagotonics and normotonics in the frequency range from 0.04 to 0.15 Hz. Sympathotonics have one wave of orthopedic reactivity with maxima at 0.09 Hz in the low heart rate range. Normotonics have two waves of reactivity per orthoprobe with frequencies of 0.08Hz and 0.11 Hz. Parasympathotonics also have two waves with frequencies of 0.07 Hz and 0.09Hz. Prospects for further research include elucidation of the mechanisms of tRR wave formation depending on the level of vegetative tone under different conditions. Key words: wave structure of heart rhythm, vegetative tone, sympathotonics, normotonics, vagotonics.

PSYCHOPHYSIOLOGICAL STATUS OF MEN AND WOMEN IN COMBAT SPORTS

Aim. The article aims to assess the psychophysiological characteristics of skilled athletes in combat sports (boxing, freestyle wrestling, judo). Materials and methods. 18–23-year-old skilled combat athletes were examined. All athletes were divided into the following groups: the first group - female athletes (n = 15); the second group - male athletes (n = 17); the third and fourth groups - control groups consisted of males and females of the same age and not involved in sports (15 people each). The following methods were used: a pulse measurement, psychological tests, self-assessment of the psychoemotional status, electroencephalography, cardiointervalography with the calculation of statistical indicators of heart rate. Examinations were performed before and after the relaxation exercise, which was a three-minute concentration of attention at a specific point on the body. Results. The results revealed that female athletes had lower indicators of psychoemotional status than males but higher than untrained females. The indicators of psychoemotional stress were lower in female athletes than in male athletes and untrained women. For example, the indicator of personal anxiety in female athletes was 41.0 ± 1.8 versus 47.2 ± 2.5 in untrained women (P < 0.05). In female athletes, heart rate, the amplitude of the mode and voltage index (77.15 ± 2.05) in the structure of heart rate were slightly higher than in males (73.10 ± ± 1.07), which indicated greater functional stress of the heart. Relaxation led to favorable changes in EEG indicators and decreased functional stress of the heart in all subjects. Conclusion. It is recommended to extend the terms of sports training in female combat athletes to ensure a smooth transition to sports specialization and reduce injuries.

Informative Markers of Cardiohemodynamic State in Young Men with Different Types of Autonomic Regulation during Submaximal Bicycle Exercise Test

We performed a comparative study of urgent adaptive changes in hemodynamic and heart rate variability parameters in the process of bicycle exercise test of submaximal power in young men from Magadan oblast with different initial types of autonomic nervous regulation. The subjects (n = 71) were considered healthy based on their health record and allowed to do physical exercises. On the basis of the heart rate variability indices at rest, we determined the initial type of autonomic regulation (normovagotonic or normosympathicotonic) in all subjects (the types differ in their heart rate structures). The subjects underwent a 150-W submaximal bicycle exercise test for 6 min with a pedaling rate of 60 rpm. It was found that the young men of the call-up age with normovagotonic regulation type have more functional reserves and less tension when performing a strenuous exercise. A more than 14- and 7-fold decrease in the total spectral power at the first 2 min of exercise (vs. the baselines) in normovagotonic and normosympathicotonic subjects, respectively, indicates that the former have higher cardiohemodynamic functional reserves and a higher tolerance to exercise.

Assessing the fractal structure of heart rate by the temporal spectrum of scale exponents: a new approach for detrended fluctuation analysis of heart rate variability

Detrended fluctuation analysis (DFA) is the most popular method for assessing the fractal characteristics of heart rate (HR). Traditionally, short-term and long-term scale coefficients, α(1) and α(2), are calculated from DFA. We recently showed that the traditional approach oversimplifies a more complex phenomenon better represented by a continuous spectrum of scale coefficients. In this paper we present a DFA based method for describing the HR fractal dynamics with a temporal spectrum of scale exponents, α(t), rather than by a model of lumped parameters, α(1) and α(2). Since α(t) is a function of the temporal scale, its interpretation is facilitated when conditions with different mean HR are compared. In this work, we reanalyze HR data, collected by our group in previous studies, by applying the proposed α(t) spectrum. We quantify the effects of gender, ageing, posture and activity level, and the alterations induced by exposure to high and very-high altitude hypoxia, on α(t). Most of the results may be interpreted in terms of changes of cardiac autonomic regulation, and indicate clearly that the new proposed DFA spectrum provides a more faithful and interpretable description of the HR fractal dynamics than traditional α(1) and α(2) scale coefficients.

Individual typological profiles for human heart rate under local cold and hypoxic exposures

1. Examining male residents of the Russian Far-East, changes in their heart rate structures and temperature variations on the hand surfaces under hypoxic and local cold factor were studied. 2. Reliable differences in statistical and spectral-wave indices of human heart rate and hand surface thermal pattern depending on the level of nonspecific resistance. 3. It is possible to select persons resistant to low temperature and oxygen deficiency by their heart rate responses to hypoxia and local cold impacts.