Heart rate variability in normotensive healthy children with aging

Area of Science:

• Pediatric Cardiology
• Autonomic Nervous System Function
• Human Physiology

Background:

• Heart rate variability (HRV) typically declines with age in adults.
• HRV patterns in children exhibit diverse changes, necessitating specific investigation.
• Understanding HRV development in children is crucial for assessing cardiovascular health.

Purpose of the Study:

• To examine the relationship between HRV, age, physique, and blood pressure in healthy school-aged males.
• To determine how different age and physique groups influence HRV parameters.
• To elucidate the factors driving HRV changes during childhood.

Main Methods:

• Studied 70 healthy male school children aged 6-12 years.
• Categorized subjects into three age groups and three physique (obesity index) groups.
• Utilized 24-hour ambulatory electrocardiography to spectrally analyze HRV components (TF, LF, HF, LF/HF ratio).

Main Results:

• Significant age-related increases were observed in total frequency (TF), low-frequency (LF) HRV components, and the LF/HF ratio.
• HRV values demonstrated a positive correlation with increasing age across the studied groups.
• Physique (thin, normal, obese) showed no significant effect on HRV values in this cohort.

Conclusions:

• Age, rather than physique, is a significant determinant of HRV changes in school-aged children.
• The observed increase in HRV with age likely reflects the maturation and development of the autonomic nervous system.
• Findings highlight the importance of age-specific reference ranges for pediatric HRV assessment.