Reproducibility of 24-h heart rate variability in children

Area of Science:

• Pediatric Cardiology
• Autonomic Nervous System Function

Background:

• Time-domain heart rate (HR) variability (HRV) analysis is used to assess cardiac autonomic tone in pediatric clinical settings.
• The long-term consistency of 24-hour time-domain HRV measurements in children remains under-investigated.

Purpose of the Study:

• To evaluate the reproducibility of 24-hour time-domain HRV indices in healthy children.
• To determine the reliability of specific HRV parameters for assessing cardiac autonomic tone in pediatric populations.

Main Methods:

• Investigated reproducibility of 24-hour HRV time-domain indices in 39 healthy children, with recordings 1 day apart.
• Analyzed standard deviation of NN intervals, standard deviation of 5-min NN interval averages, and RMSSD (uncorrected and HR-corrected).
• Assessed reproducibility using intraclass correlation coefficients, standard error of measurement, coefficients of variation, and Bland-Altman plots.

Main Results:

• The standard deviation of all adjacent NN intervals corrected for HR demonstrated the highest reproducibility.
• This parameter achieved the highest intraclass correlation coefficient (0.987) and lowest coefficient of variation (5.5%).
• Bland-Altman plots confirmed the best agreement between the two 24-hour recordings for the HR-corrected standard deviation of NN intervals.

Conclusions:

• The standard deviation of all adjacent NN intervals corrected for HR is a consistent and reproducible measure.
• This HRV parameter allows for reliable identification of cardiac autonomic tone in children using 24-hour ambulatory recordings.