THE STUDY OUTCOMES OF THE NEGATIVE IMPACT OF HEXACHLOROCYCLOHEXANE ON VEGETOVASCULAR REGULATION OF NEWBORNS' CARDIAC RHYTHM.

Introduction: One of the most adverse chemical factors of the outdoor environment is pesticides entering the organism of newborns via mother's breast milk, and also receive a pesticide load through a polluted environment. The heavy demonstration of pesticides impact on the brain is violation of autonomic regulation mechanisms of newborns' cardiac rhythm. The purpose of the study is early detection of violation of autonomic regulation mechanisms of cardiac function of children with perinatal hypoxia in the region of hexachlorocyclohexane use in cotton planting.

Material and methods: The hygienic state of the environment of the cotton planting region has been studied by means of measurement of pollution level of the atmospheric air, water and soil with pesticide hexachlorocyclohexane, the concentration of which was in 7,55-9,38 more than their maximum permissible concentration (MPC). 148 children took part in the study who were treated in neonatal center of Turkestan Regional Children's Clinical Hospital in Shymkent city. 30 infants without any signs of hypoxic-ischemic syndrome were assigned to the comparison group (I group). 118 children with signs of hypoxic-ischemic central nervous system injury were included in the study group and were divided into 1 and 2 subgroups. Among them 85 children with detected hypoxic-ischemic central nervous system injury of I-II degree were included in the 1st subgroup, and 33 children with cerebral hypoxic-haemorrhagic central nervous system damage of III degree in the 2nd subgroup. The study has been carried out by means of Holter monitoring using instrumental-software system "Kardiotechnika-4000" within 15-38 days of infants' lives.

Results: Advanced complex of QRS prevails in infants who underwent a heavy perinatal hypoxia. Changes in this electrocardiogram are one of the most unfavorable heart changes and is indicative of bioelectric myocardium instability. Using a program to compare short records of cardiac rhythm, the average daily value of the indicator was calculated. The use of such method enables elimination of such impact of long-term malignant causes in the spectrum. The analysis of heart vegetative reaction conducted among infants of 15-22-day age demonstrated decrease of parasympathetic impact on heart rate of I group infants, and activity of sympathetic segment of vegetative nervous system was unchanged. So, the decrease of parasympathetic impact on heart rate of infants in the study groups was observed in the result of Holter monitoring, but the absence of changes of sympathetic effect in general. It was reflected by the increase of the value of vagosympathetic index (LF/HF), similarly to this disease suggesting low evidence of respiratory sinusal arrhythmia.