HRV in Children

Methods

Multi-parametric study and meta-analysis of ADHD and HRV

Key Findings

• Children with ADHD show 15-25% lower RMSSD than controls
• Reduced parasympathetic activity during rest and tasks
• HRV differences correlate with symptom severity
• Some stimulant medications may improve HRV
• HRV biofeedback being explored as adjunct treatment

Limitations

Medication effects complicate interpretation, varied age ranges

Methods

Meta-analysis of HRV studies in autism spectrum populations

Key Findings

• Reduced resting vagal tone in autistic individuals
• Atypical HRV responses to social and sensory stimuli
• Lower HRV associated with more anxiety and sensory issues
• Some pilot studies show HRV biofeedback may help
• Individual variation is substantial

Limitations

Heterogeneous autism presentations, limited intervention data

Methods

AHA scientific statement review of adolescent cardiovascular health

Key Findings

• Late sleep timing associated with lower HRV in teens
• Weekend-weekday sleep differences correlated with reduced HRV
• Social jet lag impacts autonomic function
• Early intervention may prevent long-term effects
• Screen time before bed exacerbates circadian disruption

Limitations

Observational data, many confounding factors in adolescence

Methods

Studies of HRV during emotional challenges in preschoolers

Key Findings

• Higher HRV correlates with better self-regulation
• HRV during challenges predicts task performance
• Children with behavior problems display lower HRV
• HRV biofeedback improves self-regulation in children
• Teacher-child relationships influence HRV development

Limitations

Individual development rates vary significantly

Methods

Review of HRV applications in youth sports

Key Findings

• About 30% of young athletes experience overtraining
• Reduced HRV may signal overreaching before symptoms
• HRV helps optimize training loads for young athletes
• Burnout is primary reason for youth sports attrition
• AI models integrating HRV show promise for risk prediction

Limitations

Age-appropriate norms still being established

Methods

Longitudinal study from third trimester through 18 months

Key Findings

• Fetal HRV measured remotely during third trimester
• Low fetal HRV may indicate developmental vulnerability
• Parenting stress interacts with fetal HRV for outcomes
• Early autonomic patterns may predict later development
• Non-invasive monitoring increasingly feasible

Limitations

Complex interactions with postnatal factors