Heart rate variability in the neonate and infant: analytical methods, physiological and clinical observations

Naturally occurring oscillations in heart rate have long been considered to reflect the modulating influences of the autonomic nervous system. Individ ual reports of heart rate variability in healthy and sick neonates and infa nts have provided valuable information as to pathophysiological changes in autonomic cardiovascular control. It is evident that prematurity and poor h ealth are reflected in attenuated heart rate variability. However, at prese nt, there are few standard criteria for the analysis of heart rate variabil ity, preventing precise comparisons among the various studies. Until recomm endations for standardized analytical methods are made, clinical applicatio n of heart rate variability in neonatal and infant prognosis and therapy re mains premature.