Campbell H, et al. - Whether or not infants with hypoxic-ischemic encephalopathy and evidence of autonomic dysfunction display aberrant physiologic responses to care events that could contribute to evolving brain injury was determined. Infants with impaired autonomic nervous system (ANS) function at risk for maladaptive responses to care events were detected via heart rate (HR) variability metrics. Therefore, HR variability was shown to beneficial as a real-time, continuous physiologic biomarker to guide neuroprotective care in high-risk newborns.