Normal Heart Rate Ranges for Pediatric Patients by Age
The normal heart rate in pediatric patients varies significantly by age, with newborns having the highest rates (median 127-145 bpm) that progressively decline through childhood to adolescent values approaching adult norms (median ~113 bpm by age 2 years).
Age-Specific Normal Heart Rate Ranges
Newborns (Birth to 1 Month)
- Median heart rate at birth is 127 bpm, increasing to a peak of 145 bpm at approximately 1 month of age 1
- During the first 24 hours of life, the 50th percentile is 126 bpm at 2 hours, then stabilizes at 120-122 bpm 2
- The 2nd to 98th percentile range is 102-162 bpm at 2 hours, narrowing to 96-156 bpm thereafter 2
- Maximum awake heart rate ranges from 150-222 bpm (mean 192 bpm), while minimum awake rate ranges from 78-140 bpm (mean 107 bpm) 3
- During sleep, maximum rates range from 125-210 bpm (mean 168 bpm) and minimum rates from 72-120 bpm (mean 92 bpm) 3
Infants and Young Children (1 Month to 2 Years)
- Heart rate shows the steepest decline during the first 2 years of life, decreasing from the 1-month peak of 145 bpm to a median of 113 bpm by age 2 years 1
- This rapid decline reflects maturation of the autonomic nervous system during early childhood 4
Children (2 to 18 Years)
- Heart rate continues to decline progressively from early childhood through adolescence 1
- The rate of decline is less steep after age 2 years compared to infancy 1
- Age-related changes must be considered when evaluating whether a heart rate is normal 5
Important Clinical Considerations
Factors Affecting Heart Rate Interpretation
- Awake infants have mean heart rates 5.6 bpm higher than when asleep 2
- Skin-to-skin contact (on mother's chest) increases heart rate by 4.9 bpm compared to lying in a cot 2
- Girls have slightly higher heart rates than boys (1.6 bpm difference) 2
- Each 0.1°C increase in rectal temperature raises heart rate by 0.5 bpm 2
- Individual variation is substantial, with considerable fluctuation in the same infant over 24 hours 2
Common Pitfalls to Avoid
- Do not apply adult heart rate standards to pediatric patients, as this leads to misinterpretation of normal physiologic variation as pathology 6
- Failure to account for age-specific ranges can result in unnecessary interventions or missed abnormalities 5
- When evaluating for tachyarrhythmias like SVT, use age-appropriate thresholds: generally >180 bpm in children and >220 bpm in infants 7
Autonomic Nervous System Maturation
- Heart rate variability indices show progressive maturation of autonomic control throughout childhood 4
- This maturation explains the age-related decline in baseline heart rate from infancy through adolescence 4
- Cardiac rhythm and conduction appear more stable in newborns than in older children, with bradycardia and ventricular ectopy being uncommon in the neonatal period 3