Statistical analysis of heart rates in subsequent victims of sudden infant death syndrome.

An analysis was made of heart rate records obtained prospectively from a group of full-term infants. The group consisted of 16 subsequent victims of sudden infant death syndrome (SIDS) and a set of 49 controls. The power spectra were calculated for each record and this together with the birth weight, gestational age and age at recording provided the basis for a discriminant analysis. The analysis identified a periodicity of 6-8 heart beats, in addition to the known effect of low birth weight, as associated with the risk of SIDS.