Spectral analysis of heart rate variability signals in newborns: physiological and clinical aspects

The development of the neural control mechanism in newborns is evaluated using the power spectral analysis of the discrete series of R-R intervals. The analysis is carried out on 20 healthy subjects after spontaneous delivery in active sleep (AS), quiet sleep (QS) and transition phase (TP). The recordings were made just after the delivery and three days later, before the dismission from the hospital. The results show that it is possible to quantitatively confirm a predominance of sympathetic activation during AS and vagal activation during QS. There is a strong difference in the variance passing from the first day to the third day after the birth. No appreciable differences are noted in the autonomic balance in 5 subjects delivered by caesarean section in comparison with the spontaneously delivered newborns