Mp. Villa et al., Effects of sleep stage and age on short-term heart rate variability duringsleep in healthy infants and children, CHEST, 117(2), 2000, pp. 460-466
Citations number
34
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Study design: power spectrum analysis of heart rate variability (HRV) is a
noninvasive technique that provides a quantitative assessment of cardiovasc
ular neural control. Using this technique, we studied the autonomic nervous
system changes induced by sleep in 14 healthy subjects: 7 infants (mean ag
e, 9.40 +/- 2.32 months) and 7 children (mean age, 8.93 +/- 0.65 years) dur
ing a standard all-night polysomnographic recording. Our primary aim was to
assess the effect of sleep stage and age on short-term HRV during sleep in
healthy infants and children. Power spectral density was estimated by auto
regressive modeling over 250 consecutive R-R intervals. In this study, we m
ainly considered two spectral components: the high-frequency (HF) component
(0.15 to 0.40 Hz), which reflects parasympathetic cardiovascular modulatio
n; and the low-frequency (LF) component (0.04 to 0.15 Hz), generally consid
ered due to both parasympathetic and sympathetic modulation.
Results: Heart rate was higher (p < 0.01 in all sleep stages) and total pow
er ion er (p < 0.02) in infants than in children. HF power was higher in ch
ildren than in infants (p < 0.05). In infants and children, the ratio betwe
en LF and HF powers changed with the various sleep stages (p < 0.02 in infa
nts; p < 0.01 in children): it decreased during deep sleep and increased du
ring rapid eye movement sleep. However, it was invariably lower in children
than in infants,
Conclusion: These findings show that the sleep stage and age both significa
ntly influence short-term HRV during sleep in healthy infants and children.
Hence, to provide unbiased results, HRV studies investigating the effects
of age on autonomic nervous system activity should segment sleep into the f
ive stages. In addition, despite a relatively small study sample, our data
confirm greater parasympathetic control during sleep in children than in in
fants.