title: Heart-rate variability in low-risk prematurely born infants reaching normal term: a comparison with full-term newborns.
abstract: To investigate the influence of prematurity and postnatal age on the maturation of the autonomic nervous system function, we analysed heart-rate and heart-rate variability in twelve prematurely born infants (< 37 weeks gestational age) reaching the conceptional age of 37-41 weeks. These neonates were compared with sixteen 37-41 week conceptional age newborns (< 10 days postnatal age). Heart-rate variability was analysed by spectral analysis of interbeat intervals using Short-Time Fourier Transform. We found that during both active and quiet sleep, the durations of RR-intervals were shorter and the amplitude of heart-rate variability in different frequency bands was lower in prematures reaching term than in newborns of the same conceptional age (P < 0.001). Between-state comparison showed differences in both groups. In both groups, low-frequency heart-rate variability was higher in active sleep than in quiet sleep. Between-state differences of RR-intervals and high-frequency heart-rate variability were present only in newborns (P < 0.01). Discrimination between newborns and prematures reaching term, based on RR-intervals and heart-rate variability, was correct in both sleep states with errors between 7 to 16%. However, in both newborns and prematures reaching term, between-state discrimination showed less reliable results, especially for quiet sleep discrimination with 24% (in PRT) and 20% (in NB) of errors. Our results, especially information given by factor analysis, suggest that the differences between newborns and prematures reaching term, concerning RR-interval and heart-rate variability, may be related to a changed balance between the sympathetic and parasympathetic nervous systems with a diminished parasympathetic component of heart rate control in prematures reaching term, as compared to newborns.
authors: Institute of Pathological Physiology, Friedrich Schiller University, Jena, Germany.
authors: M
authors: M
authors: Eiselt
authors: L
authors: L
authors: Curzi-Dascalova
authors: J
authors: J
authors: Clairambault
authors: F
authors: F
authors: Kauffmann
authors: C
authors: C
authors: Médigue
authors: P
authors: P
authors: Peirano
mesh_terms: D016002:Discriminant Analysis; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D007234:Infant, Premature / Q000254:growth & development / Q000502:physiology*; D012307:Risk Factors; D012890:Sleep / Q000502:physiology