The relationship between heart rate variability and school performance

Abstract

This study investigated the relationship between heart rate variability and the duration of intervals, waves and complexes of the electrocardiogram and academic performance in pupils aged 7-16 years. The study of the parameters of the heart rate variability was carried out using the method of cardiointervalography according to Baevsky R. M. To study the time parameters of the electrocardiogram and the parameters of the heart rate variability, the Alton-03 electrocardiograph was used. A series of consecutive cardiointervals for calculating the parameters of heart rate variability in schoolchildren was obtained by recording an ECG in three standard leads. The duration of cardiac intervals in the second standard lead was measured on ECG printouts. High heart rate variability has been detected in pupils with good academic performance in school. In particular, in advanced junior schoolchildren aged 7 to 11, almost all the studied HRV parameters indicated better regulation of the heart rhythm by the central nervous mechanisms of regulation. In adolescent children aged 12 to 16, there were no significant differences between successful and unsuccessful students in many HRV parameters. Significant differences were noted in the magnitude of the variation range and some HRV indices. In adolescents with good academic performance, along with an increase in the influence of parasympathetic influences on the work of the heart, a rather high level of activity of the sympathetic link remains. This is evidenced by the absence of differences in many HRV parameters - shorter values of the mode value, cardiointerval and high heart rate - between successful and unsuccessful adolescents. Thus, in successful adolescent children, a high activity of the sympathetic link of the central nervous mechanisms of regulation of the rhythmic activity of the heart remains. The work also discusses the cellular mechanisms of coordination of local and central levels of regulation of the growing with age influence of the parasympathetic nervous system on the heart rate and maintaining high activity of the sympathetic link in adolescent children. In children in two age groups, 7-11 and 12-16 years old, the value of the variation range and such HRV indices as the autonomic balance index and the autonomic rhythm index were more associated with academic performance. According to these parameters, significant differences remained in both groups studied between the successful and the non-successful students. At the same time, they testified to the better central regulation of the heart rhythm in advanced schoolchildren.