Short term heart rate variability in healthy neonates: normative data and physiological observations.
BACKGROUND
The measurement of heart rate variability (HRV) reveals information on the functional state of the autonomic nervous system (ANS). Moreover, several diseases are known to be accompanied by a reduction in HRV. Currently, there are no data on HRV within larger samples of healthy neonates.


OBJECTIVE
This study was initiated to establish normative data of HRV parameters and to assess physiological observations in healthy newborn infants.


METHODS
We performed 10 min recordings of HRV in 80 healthy neonates. We computed time domain parameters. Furthermore power spectrum analysis was calculated by Fourier Transformation in 3 frequency bands. The total power as well as the peak frequencies was estimated for each band.


RESULTS
The normative data of each HRV parameter for healthy newborns are presented as mean, standard deviation and the 5th and 95th percentiles. Increasing postnatal age is accompanied by a significant (p<0.05) elevation of HRV parameters. Baroreceptor loop fluctuations were delayed from 0.1 Hz (adults) to 0.07 Hz in healthy newborns. A respiratory peak according to respiratory sinus arrhythmia (RSA) as it is common in adults was not detectable.


CONCLUSIONS
Normative data of HRV allows the interpretation of clinical data in neonatal diseases affecting the ANS. Moreover, we observed physiological deviations in healthy newborns in comparison to adults.
Longin
Elke
E
University Children's Hospital, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany. elke.longin@kikli.ma.uni-heidelberg.de
Schaible
Thomas
T
Lenz
Tamara
T
König
Stephan
S
D001341:Autonomic Nervous System / Q000502:physiology; D004562:Electrocardiography; D005260:Female; D005583:Fourier Analysis; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn / Q000502:physiology*; D008297:Male; D012016:Reference Values; D018709:Statistics, Nonparametric