Related Experiment Video
Updated: Jan 31, 2026
Studying Brain Function in Children Using Magnetoencephalography
Published on: April 8, 2019
Early Heart Rate Variability and Electroencephalographic Abnormalities in Acutely Brain-Injured Children Who Progress
Juan A Piantino1, Amber Lin2, Daniel Crowder1
1Department of Pediatrics, Division of Child Neurology, Doernbecher Children's Hospital, Oregon Health and Science University, Portland, OR.
Insights
Lower heart rate variability in brain-injured children may predict progression to brain death, indicating early autonomic system failure. This finding is linked to central nervous system dysfunction markers like electroencephalogram abnormalities.
Area of Science:
- Neurology
- Autonomic Nervous System Function
- Critical Care Medicine
Background:
- Heart rate variability (HRV) reflects autonomic nervous system control.
- Autonomic control is lost after brain death, leading to decreased HRV.
- Early HRV changes as predictors of brain death progression are not well understood.
Purpose of the Study:
- To investigate if lower HRV in brain-injured children predicts progression to brain death.
- To determine if HRV is an early indicator of autonomic system failure in pediatric brain injury.
- To explore the association between HRV and markers of brain dysfunction.
Main Methods:
- Retrospective case-control study in a pediatric intensive care unit.
- Included children (up to 18 years) with Glasgow Coma Scale < 8 and available ECG data.
- Analyzed HRV using time domain, frequency domain, Poincaré plots, and approximate entropy.
Main Results:
- Patients progressing to brain death had significantly lower HRV across multiple metrics (p < 0.01).
- Decreased low and high frequency HRV power increased the odds of death (OR 4.0 and 2.5, respectively).
- Lower HRV correlated with abnormal electroencephalogram findings (discontinuous or attenuated/featureless).
Conclusions:
- Reduced HRV is a potential early indicator of autonomic system failure preceding brain death in children.
- HRV changes are associated with central nervous system dysfunction markers, including EEG abnormalities.
- These findings support HRV monitoring for predicting brain death in pediatric critical care settings.
Objectives:
Heart rate variability is controlled by the autonomic nervous system. After brain death, this autonomic control stops, and heart rate variability is significantly decreased. However, it is unknown if early changes in heart rate variability are predictive of progression to brain death. We hypothesized that in brain-injured children, lower heart rate variability is an early indicator of autonomic system failure, and it predicts progression to brain death. We additionally explored the association between heart rate variability and markers of brain dysfunction such as electroencephalogram and neurologic examination between brain-injured children who progressed to brain death and those who survived.
Design:
Retrospective case-control study.
Setting:
PICU, single institution.
Patients:
Children up to 18 years with a Glasgow Coma Scale score of less than 8 admitted between August of 2016 and December of 2017, who had electrocardiographic data available for heart rate variability analysis, were included.
Exclusion Criteria:
patients who died of causes other than brain death. Twenty-three patients met inclusion criteria: six progressed to brain death (cases), and 17 survived (controls). Five-minute electrocardiogram segments were used to estimate heart rate variability in the time domain (SD of normal-normal intervals, root mean square successive differences), frequency domain (low frequency, high frequency, low frequency/high frequency ratio), Poincaré plots, and approximate entropy.
Interventions:
None.
Measurements And Main Results:
Patients who progressed to brain death exhibited significantly lower heart rate variability in the time domain, frequency domain, and Poincaré plots (p < 0.01). The odds of death increased with decreasing low frequency (odds ratio, 4.0; 95% CI, 1.2-13.6) and high frequency (odds ratio, 2.5; 95% CI, 1.2-5.4) heart rate variability power (p < 0.03). Heart rate variability was significantly lower in those with discontinuous or attenuated/featureless electroencephalogram versus those with slow/disorganized background (p < 0.03).
Conclusions:
These results support the concept of autonomic system failure as an early indicator of impending brain death in brain-injured children. Furthermore, decreased heart rate variability is associated with markers of CNS dysfunction such as electroencephalogram abnormalities.
More Related Videos
Related Concept Videos
01:31Regulation of Heart Rates
The SNS increases heart rate through the release of norepinephrine and epinephrine, which act on beta-1 adrenergic receptors in the heart. This action increases the rate of depolarization in the sinoatrial (SA) node, the heart's...
01:30Factors Influencing Heart Rate
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
02:23Abnormal Proliferation
01:19Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart...
02:53Reaction Rate
The mathematical representation of the change in the concentration of reactants and products, over time, is the rate...
01:23Brain Waves