Reproducibility and seasonal variation of ambulatory short-term heart rate variability in healthy subjects during a self-selected rest period and during sleep.
Although ambulatory measurements of heart rate variability (HRV) are widely used, the reproducibility and seasonal variation of ambulatory sampled short-term HRV measurements in healthy participants has not been investigated before. In the present study we collected ambulatory ECGs from 19 healthy participants monthly for 12 months, and for a sub-group of 12 participants weekly for one month. Frequency-domain HRV-metrics were calculated for 5 min ECG segments during (i) a 15-min self-selected rest period (awake period), and (ii) a 30-min sleep period starting 45 min after estimated sleep onset. Total, within- and between-subject coefficient of variation (CV) and seasonal variation were estimated for ln (TP), ln (LFP), ln (HFP), ln (LF/HF), LFnu, HFnu, the mean heart period and the ECG derived respiratory frequency.The within- and between-subject CV varied considerably between different variables, from < 10% for ln (TP) and ln (LFP) to >100% for ln (LF/HF). Within- and between-subject CV of ln (HFP), LFnu and HFnu were 10-40%. A weak, but significant, seasonal variation was found for ln (TP) (p = 0.05), ln (LFP) (p<0.05) and the respiratory frequency (p<0.01), but the seasonal variation did not affect the within-subject CV. Furthermore, sample size calculations demonstrated that the reproducibility was sufficient for ambulatory HRV measurements to be used to study autonomic cardiac regulation in healthy populations.
National Research Centre for the Working Environment, Lersø Parkallé 105, Copenhagen DK-2100, Denmark. jkr@nrcwe.dk
Jesper
J
Kristiansen
Annemarie
A
Olsen
Jørgen H
JH
Skotte
Anne Helene
AH
Garde
D015716:Electrocardiography, Ambulatory; D005260:Female; D006262:Health; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012119:Respiration; D012146:Rest / Q000502:physiology*; D012621:Seasons; D012890:Sleep / Q000502:physiology*; D013997:Time Factors