[Heart rate variability during sleep in children with multiple disabilities].

Objectives: To study heart rate variability during sleep in children with multiple disabilities in order to observe the behavior of the autonomic nervous system.
Methods: The R-R interval variability of 4 to 12 years old children was recorded with a heart rate monitor during one night. Children with multiple disabilities (G1) and healthy children (G2) were compared in time, frequency, and non-linear domains.
Results: Temporal (P<0.01), frequency (P<0.05), and non-linear (P<0.01) variables in the G1 were lower than in the G2 group.
Discussion: The time and frequency analysis confirmed the predominance of the sympathetic nervous system during sleep in G1 children. Reduced non-linear variables can explain sleep with less informations (correlation dimension: 2.203 ± 1.239 versus 3.842 ± 0.378; P<0.001), less complex cycles of sleep (approximate entropy: 1.153 ± 0.200 versus 1.365 ± 0.099; P<0.01), and a reduced correlation in short-term variability (SD1: 42.37 ± 19.0 (ms) versus 73.44 ± 25.3; P<0.01). The fractal structure of the recordings was not affected (P>0.05). The diseases encountered are probably the reason for these findings, but the variety of disorders and medications of the children with multiple disabilities needs to be studied with a larger and more varied sample.
Conclusion: Sympathetic predominance during sleep in children with multiple disabilities is associated with a decrease in adaptive abilities of these children's autonomic nervous system.
(Copyright © 2013 Elsevier Masson SAS. All rights reserved.)