Infant heart-rate variability and behavioral developmental status

Abstract

Physiological recordings of heart rate (HR) and HR variability were taken in a baseline recording of infants at 14, 20, and 26 weeks of age. The measures included HR mean, HR standard deviation, and respiratory sinus arrhythmia (RSA). The Bayley Developmental Exam was given at 26 weeks of age for one group and at 26 and 52 weeks of age for a second group. Parental report of temperament was obtained with the infant Temperament Questionnaire at 26 weeks of age. The Bayley Mental Development Index (MDI) was significantly correlated with concurrently recorded HR level and standard deviation of HR. The approach subscale of the temperament rating was consistently positively correlated with RSA at each of the baseline recording ages, whereas the other temperament measures were inconsistently associated with physiological measures. Stability of the HR variability measures was associated with concurrent developmental level, as well as good developmental outcome at 12 months. These results support the position that variability in HR may be indexing important physiological phenomena which are strongly associated with the developmental status of the young infant.