Self-Regulation of Emotional Stress
Human Physiology, Vol. 26, No. 5, 2000, pp. 641-642. Translated from Fiziologiya Cheloveka, Vol. 26, No. 5, 2000, pp. 151-152. Original Russian Text Copyright © 2000 by Shcherbatykh.
Self-Regulation of Autonomic Homeostasis in Emotional Stress
Yu. V. Shcherbatykh
Burdenko State Medical Academy, Voronezh, Russia Received January 14, 2000
Emotional stress is considered to be one of the basic pathogenetic factors causing diseases of the cardiovascular system . Its particular example is the examination stress, which develops in some students expecting an examination. In this case the reactions of the autonomic system in some persons can be oppositely directed and reach a magnitude that puts an organism on the borderline between norm and pathology . Therefore, the qualitative and quantitative estimation of the character of the reaction of the autonomic system to stress in students and the development of the methods of its correction are relevant.
To study the influence of self-regulation of mental and physiological processes under conditions of examination stress, a complex investigation of the I- П - уеаг students (n = 28) of both sexes, age 1 to 20 years, was carried out. The control group included 102 students of the same sex and age, who did not undergo correctional procedures. In both groups of students, the level of situ-ational anxiety was defined according to Spielberger. The basic parameters of hemodynamics (heart rate and arterial pressure) were measured, and mathematical analysis of cardiac rhythm was performed according to the recommendations of the working group of the European Society of Cardiologists and the North-American Society on Stimulation and Electrophysiology . By means of the Varikard 1.4 device (produced by the Rom-ena Company, Ryazan, Russia), the following parameters were investigated: the dynamics of moda amplitude (AMo) and the root-mean-square deviation of the cardio-intervals (SDNN), and the capacity of the respiratory (HF) and vasomotor waves (LF) of the spectrum of variable cardiointervals during preparation for and taking of examinations. The data obtained were processed statistically with application of the program STATGRAPHICS Plus for Windows.
The investigation demonstrated that the average level of situational anxiety in a quiet state in the experimental group determined according to the Spiel-berger's questionnaire was 39.8 ±1.4 points. Before the examination, this parameter was considerably elevated achieving, on the average, 56.6 ± 2.8 points (p < 0.001), which testified to a rather high level of situational anxiety in students. The average parameters of arterial pressure in this group in the normal state were 114.3 ± 1.3 mmHg for systolic pressure and 73.1 ± 1.1 mmHg for diastolic pressure. Before the examination, there was a significant augmentation of the parameters of arterial pressure. The systolic pressure was elevated up to 124.2 ± 2.1 mm Hg and the diastolic pressure to 80.9 ± 1.9 mm Hg (p < 0.01); the heart rate was 102.1 ±1.8 beats/min compared to the normal value of
78.2 ± 0.9 beats/min (p < 0.001). The AMo parameter increased by the beginning of the examination from 32.6 ± 0.9 up to 44.5 ± 1.4% (p < 0.01), which pointed to activation of the sympathetic system. The SDNN parameter diminished from 63.3 ± 2.8 to 34.0 ± 2.3 ms (p < 0.001), which shows a substantial decrease in tension of the parasympathetic nervous system [3-4]. The fall of the absolute capacity of respiratory waves from 980 ± 90 to 280 ± 70 ms2 (p < 0.001), which reflects the activity of the vagus center according to the conventional point of view, is also indicative of this fact [3, 5-8].
A complex of methods of self-regulation tested in the Voronezh Medical Academy was applied for correcting the level of emotional stress [2, 9]. It consisted of three parts: concentration on respiration , general body relaxation with the help of autogenic training [9, 11], and creation of a mental program of successfully passing an examination . At the first stage, the attention focus was switched from external stimuli (alarming ideas on the forthcoming examination) to internal processes, which provided the initial decrease in anxiety level. At the second stage, the highest mental and'muscular relaxation was achieved with the help of the autogenic training. The third, final, exercise of the complex was directed to creating a strategy of successful behavior during an examination. The students were told to create a mental model of successfully passing an examination and to "play" this situation in their minds several times. After the last exercise, was performed there was some activation of the sympathetic system, which, however, did not achieve the extremely increased initial level. In the terminology of sports psychology, our students approached the level of an optimum fighting condition of a sportsman after the end of the third exercise . Thus, the average heart rate in the group at the end of exercise was 93.4 ±1.9 beats/min (the difference from the initial level before the beginning of self-regulation was significant, p < 0.01), the arterial systolic pressure was 116.2 ± 2.3 mm Hg (p < 0.05), and the diastolic pressure was 74.8 ±1.4 mm Hg (p <0.05). The average level of anxiety in this group of students measured according to the technique of Spiel-berger decreased from 56.5 ± 2.8 to 43.1 ± 2.0 points (p < 0.001). All the hemodynamic parameters were significantly below (p < 0.01) similar parameters in the control group in which no special measures for correcting stress level were used.
The mathematical analysis of cardiac rhythm has also shown a positive influence of psychological self-regulation on the autonomic homeostasis in students under conditions of emotional stress. The autogenic training resulted in a decrease in the AMo parameter of cardiac rhythm variability up to 38 ± 7% (p < 0.05) and augmentation of the SDNN parameter up to 46.2 ± 3.0 ms (p < 0.01), which meant weakening of sympathetic and intensification of parasympathetic influences on the heart [3, 4, 7]. Thus, the autogenic training augments the activity of the parasympathetic system in a greater measure (by 36%) rather than reduces the activity of the sympathetic system (by 15%). The intensification of the vagus nerve tone after autotraining is also confirmed by an increase in the capacity of the respiratory waves (HF) (from 280 ± 70 up to 540 ± 80 ms2), reflecting the level of activity of the parasympathetic part of the autonomic nervous system [3, 7, 8].
The mechanism of the elevation of the capacity of the low-frequency fluctuations (LF-component of the spectrum or the vasomotor waves), which was observed in our experiments after application of self-regulation methods by the students, is not so clear. Some authors consider the LF-waves to be the marker of activity of the sympathetic centers , other researchers do not exclude participation of the parasympathetic system in generation of this waves [5-8], still others assume a complex nature of LF-fluctuations . An increase in the absolute capacity of vasomotor waves (from 1050 ± 100 up to 1520 ± 90 ms2) and their relative part in the general spectrum of cardiac rhythm variability (from 39.3 ± 2.3 up to 50.9 ± 4.1%) observed in our experiments after autogenic training give grounds to suggest that LF-fluctuations are more likely related to generators of the parasympathetic system of the brainstem.
Hence, it can be concluded that application of the program of a complex self-regulation before the examinations allows us to decrease significantly the level of emotional strain and to restore the autonomic homeostasis disturbed by stress. The result is evident at the physiological, psychological, and behavioral levels. In
particular, the percent of unsatisfactory marks in the experimental group was 1.7 times less than in the control group.
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