Normal oscillometric heart rate of term African infants in the early days of life

Abstract

Background: Heart rate (HR) measurement is an important means of evaluating clinical status of newborns. Differences in HR between caucasian and negroid infants have been reported. Clinical estimation of HR is less accurate than estimates using devices.Aim: To establish the normal HR of term negroid newborns in the early days of life using an oscillometric device.Methods: The mean of three HR readings of consecutively recruited term newborns was obtained with Dinamp 8100 monitor (Critikon, Tampa, FL). On recruitment, the infants were aged between 1 and 4 days. Gestational age was determined by menstrual dates and the Dubowitz method.Results: A total of 473 term newborns were recruited, 229 (48·4%) of whom were males. Median HR was 132 (range 90–189) beats per minute (bpm). The lowest median HR (130 bpm) was obtained on the 3rd day of life and this was significantly different from the highest value of 138 bpm recorded on the 4th day of life (P = 0·025). The 5th and 95th percentiles were 111 and 158 bpm, respectively.Conclusion: The lower limit of the range of oscillometrically generated normal HR in term African newborns in the early days of life is lower than that which is commonly used in clinical practice.