Neonatal heart rate variability and intraventricular hemorrhage: A case study
PURPOSE: The purpose of this study was to compare heart rate variability (HRV) in low-risk, pre-term infants to one infant diagnosed with intraventricular hemorrhage (IVH).
METHOD: A case study design was used to compare HRV of one subject diagnosed with IVH to a convenience sample of 38 low-risk, pre-term infants at 30 and 31 post-menstrual weeks of age. Heart periods were recorded for 300-s with the infant in an active sleep state. Heart rate variability was quantified by spectral analysis. A confidence interval comparison of the total spectral components (0.02-2.0 Hz), high-frequency components (0.20-2.0 Hz), and the low-frequency components (0.02-0.20 Hz) was conducted.
FINDINGS: At 30 weeks' post-menstrual age, 10 days following diagnosis, with a grade-III IVH, the low frequency components were above the 90th percentile. One week later, at 31 weeks, the low frequency components had decreased to the 27th percentile range, and the total and high frequency components were at or below the 25th percentile range of the confidence intervals for the low-risk, pre-term infants.
DISCUSSION: The neurobehavioral organization of pre-term infants is limited due to prematurity and the cumulative effect of medical complications (such as IVH). This study has implications for the use of HRV in the identification of infants diagnosed with IVH.