Heart rate variability at rest in children aged 7-11 years who survived a brain tumor, compared with age matched neurologically healthy children

Abstract

The high survival rate of children after treatment for a brain tumor (BT) requires the development of new approaches to their rehabilitation and adaptation. Heart rate variability (HRV) is a sensitive indicator of a violation of autonomic and central regulation.

The aim of the study was to compare the frequency domain, time domain and nonlinear indicators of HRV in healthy children of primary school age and children in remission after neuro-oncological disease.

Materials and methods. In two groups of children aged 7–11 years (BT, n = 35, and neurologically healthy schoolchildren, n = 34), a photoplethysmogram (PPG) was recorded (3 min in a sitting position). After extraction of RR intervals from PPG, frequency domain (spectral), time domain and nonlinear HRV analysis (Kubios HRV Standard 3.5.0) were performed. Then two groups of children were compared according to the obtained indicators by statistical criteria.

Results. Comparison of two groups of children according to the Mann-Whitney test revealed statistically significant differences in the following HRV indicators: duration of RR intervals, heart rate, SDNN, RMSSD, pNN50, Poincare plot sizes (SD1, SD2) and ApEn. All indicators reflecting variability in children with BT are lower, heart rate is higher and approximated entropy (ApEn) is higher as well. The indicators of frequency analysis do not differ significantly in children of the two groups.

Conclusion. When analyzing HRV, it is necessary to take into account the indicators obtained by different methods. Children who have undergone treatment for a brain tumor are characterized by reduced HRV according to a number of indicators of time domain and nonlinear analysis, but do not differ in the spectral characteristics of the heart rhythm.