ABSTRACT
156 children of the main group (were born to parents irradiated in the result of Chernobyl disaster), in which according to Doppler echocardiography isolated abnormal chords of the left ventricle (AHLV) identified, 44 children of control group and 50 children of referent group were involved in the study Analysis of indicators of operational regulation of heart rate in children of primary group indicate the existence of autonomic dysregulation, which has the maximum expression in children with a threshold number of isolated abnormal chords. Evidence of autonomic dysregulation in children born to parents irradiated in the result of the Chernobyl disaster with isolated AHLV requires primary and secondary prevention to reduce the frequency of unfavourable clinical course.