Dynamics of parameters of cardiac rhythm variability within the academic year at boys and girls of senior preschool age

By method of cardiointervalgraphy and spectral analysis it is carried out research of adaptic potential dy-namics in academic year at preschool children of 5-6 years. Measurements were spent in september, de-cember, march and may. Optimum parameters of cardiac rhythm variability (CRV) and its spectral char-acteristics are recorded in september. Sexual differences are not revealed. In december at boys of re-searched group CRV parameters have sharply decreased, and was essentially enlarged the frequancy of cardiac reductions that testifies to strain of regulatory systems. At girls results of the research spent in december, essentially did not differ from the meanings received in september. Thus, in december the sexual differences caused by strain of adaptic potential exclusively at boys are found out. At girls in march CRV parameters and results of spectral analysis have shown intensifying baro-reflex influences and instability of regulation contour of blood pressure. Results of the measurements spent in may, have shown intensifying a sympathetic contour of regulation irrespective of sex of children that can be treated as a condition close to adaptation failure.