Heart rate variability as a biomarker for autonomic nervous system response differences between children with chronic...

Area of Science:

• Pediatric Health
• Autonomic Nervous System Function
• Pain Research

Background:

• Lowered heart rate variability (HRV) is linked to poor health in adults.
• The role of autonomic arousal in children's well-being, particularly in chronic pain, is less understood.

Purpose of the Study:

• To compare resting HRV in children with chronic pain versus healthy controls.
• To examine HRV changes in response to acute experimental pain tasks in both groups.

Main Methods:

• Electrocardiogram recordings (5-minute baseline and post-task) were obtained from 104 healthy children and 48 children with chronic pain (aged 8-17).
• Four acute pain induction tasks were administered: evoked pressure, cold pressor, focal pressure, and conditioned pain modulation.
• Spectral analysis quantified high-frequency normalized power (cardiac vagal tone) and low-to-high frequency band power ratio (sympathetic balance).

Main Results:

• Children with chronic pain demonstrated significantly lower resting HRV (low high-frequency normalized power, high low-to-high frequency ratio) compared to healthy children.
• A significant interaction revealed that children with chronic pain had a static HRV response to pain tasks, unlike healthy children whose HRV decreased during the tasks.
• This suggests a sustained stress response in children with chronic pain, with minimal HRV adaptation to acute pain stressors.

Conclusions:

• Children with chronic pain exhibit blunted autonomic responses to acute pain stimuli.
• HRV analysis can identify physiological stress differences between children with and without chronic pain.
• Findings highlight potential targets for interventions aimed at improving autonomic regulation in pediatric chronic pain populations.