Heart rate variability in encephalopathic newborns during and after therapeutic hypothermia.

OBJECTIVE

To evaluate whether heart rate variability (HRV) measures are predictive of neurological outcome in babies with hypoxic ischemic encephalopathy (HIE).

STUDY

DESIGN

This case-control investigation included 20 term encephalopathic newborns treated with systemic hypothermia in a regional neonatal intensive care unit. Electrocardiographic data were collected continuously during hypothermia. Spectral analysis of beat-to-beat heart rate interval was used to quantify HRV. HRV measures were compared between infants with adverse outcome (death or neurodevelopmental impairment at 15 months, n = 10) and those with favorable outcome (survivors without impairment, n = 10).

RESULT: HRV differentiated infants by outcome during hypothermia through post-rewarming, with the best distinction between groups at 24 h and after 80 h of life.

CONCLUSION

HRV during hypothermia treatment distinguished HIE babies who subsequently died or had neurodevelopmental impairment from intact survivors. This physiological biomarker may identify infants in need of adjuvant neuroprotective interventions. These findings warrant further investigation in a larger population of infants with HIE.