Heart rate variability in healthy newborn infants

Area of Science:

• Neonatal physiology
• Autonomic nervous system function
• Cardiovascular research

Background:

• Heart rate variability (HRV) is a key noninvasive indicator of autonomic function in adults and older children.
• Establishing normative HRV values in newborn infants is crucial but hindered by methodological variations.
• This study addresses the need for standardized HRV data in healthy neonates.

Purpose of the Study:

• To establish normative values for heart rate variability (HRV) in normal newborn infants.
• To assess HRV using frequency-, geometric-, and time-domain analyses.
• To identify reliable HRV parameters for studying autonomic function in neonates.

Main Methods:

• Prospective evaluation of 96 asymptomatic term infants (<72 hours old) using 24-hour Holter monitoring.
• Analysis of frequency-domain (spectral analysis), geometric, and time-domain HRV parameters.
• Reporting of HRV data including means ± SD, medians, and 5th/95th percentiles for normative values.

Main Results:

• Established normative values for various frequency-, geometric-, and time-domain HRV parameters in newborns.
• Demonstrated a high correlation (r ≥ 0.85, p < 0.0001) between vagal tone-dependent parameters.
• Identified high-frequency power (frequency domain), r-MSSD, and sNN50 (time domain) as highly correlated.

Conclusions:

• Supports the use of r-MSSD and sNN50 (time-domain) as reliable surrogates for high-frequency power in newborns.
• Provides a foundation for studying parasympathetic and sympathetic activity in comparable neonatal populations.
• Facilitates standardized assessment of autonomic function in healthy newborns through reported normative HRV data.