Peculiarities of heart rate variability in children with gastroesophageal reflux disease

Abstract

Introduction. According to modern literature gastroesophageal reflux disease (GERD) is multifactorial illness. One of the most important risk factors for this disease is considered a violation of autonomic nervous system balance. The study of heart rate variability (HRV) in recent times is used as the most informative noninvasive method for quantitative assessment of autonomic regulation of heart rate.

The aim of research. Determining the characteristics of autonomic regulation in children with gastroesophageal reflux disease.

Materials and methods. The study involved 77 children with chronic gastroduodenal pathology (aged 9 to 17 years). The main group consisted of 54 children with GERD (Group 1 - 46 children with GERD with esophagitis, Group 2 - GERD without esophagitis), comparison group comprised 23 children without clinical and endoscopic manifestations of the esophagus pathology. The following methods were conducted: clinical and medical history, fibroesofagogastroduodenoscopy, intragastric pH-metry, pH monitoring in the esophagus, Holter cardiac monitoring, variational statistics, correlation analysis.

Results. 34.8% of children with GERD with esophagitis had sympathicotonia (p<0.05), 43.5% - vagotonia and 21.7% - eytoniya (p<0,05). In 29.0% of children with GERD without esophagitis  sympathicotonia was registered and the same number - vagotonia, eytoniya - in 42.0%. During the diurnal cycle predominance of sympathetic activity in children with GERD is observed, more girls with esophagitis and the presence of UCTD (undifferentiated  connective tissue dysplasia) symptoms. Girls with esophagitis had lower time analysis indices of HRV at day time relative to boys of the same group. The predominance of sympathetic activity in girls confirmed by significantly lower rates of pNN50 (p<0.05). Tension-time index at day time was significantly higher in girls with esophagitis than in boys, which also indicated the predominancy of sympathetic tone (74,4 ± 34,6 vs conv 34,2 ± 14,1, p<0, 05). At night time in girls of group 1 values of HRV were significantly lower relative to boys (p <0.05. The stress index was significantly higher at night in girls with esophagitis (53,9 ± 33,7 vs conv 15,9 ± 8,6 cu in boys, p<0.05).

For children with esophagitis with symptoms of UCTD increased activity of the sympathetic (autonomic nervous system) ANS level is characteristic. If children without UCTD SDNNi values were within 82,5 ± 12,6 ms and 94,1 ± 20,7 ms, respectively at day and at night time, than in the presence of UCTD manifestations these figures were reduced by 1.4-fold (p<0.05). Similar changes were characteristic for rMSSD and pNN50. SI analysis showed significant stress adaptation capabilities in children with esophagitis associated with UCTD.

Children with acid reflux indicators of reflecting parasympathetic activity, were almost 1.5 times lower than in children with alkaline GER (gastroesophageal reflux), but did not differ significantly from that of children with mixed GER. Thus, in children with acid GER indexes of SDNNi and rMSSD were within 62,2 ± 12,6 ms (p<0.05) and 38,4 ± 13,2 ms (p<0.05) at day time 72 9 ± 20,9 ms (p <0.05) and 56,9 ± 19,9 ms (p <0.05) at night time respectively, relative to children with alkaline GER (SDNNi amounted to 90,9 ± 32,6 ms and rMSSD - 64,0 ± 32,2 ms at day time and SDNNi - 101,6 ± 27,7 ms and rMSSD - 91,8 ± 39,2 ms at night time). Distinction of children with acid GER was significantly lower CI (circadian index) indicators, that is indicating exhaustion of adaptive reserves in these children.

Was established negative correlation of medium strength between the number  GER lasting more than 5 minutes and the time performance analysis of HRV (at day time r = -0,57; p <0.05; at night time r = -0,56; p <0.05). The more stress of sympathetic division of ANS, the bigger number of long-term GER.

Conclusion. Thus, according to the analysis of HRV in children with GERD derangements of rhythmicity and intensity of fluctuations of the sympathetic and parasympathetic parts of the ANS identify.  It was noted that the prevailing of sympathetic link of ANS is more typical for girls and in the presence of UCTD symptoms.