Circadian rhythm of spectral indices of heart rate variability in healthy subjects.
Circadian pattern of heart rate variability spectral indices, including hourly, 24-hour, night, day, morning, and sex-adjusted measures of low frequency (LF), high frequency (HF), and LF/HF, was evaluated in healthy persons in 24-hour 3-lead electrocardiogram. HF showed circadian pattern with the greatest night values and LF/HF with the smallest night values. Peaks of hourly LF were found between 5 and 9 am and between 4 and 6 pm. The smallest LF was between 11 pm and 3 am. Hourly HF peaked between 11 pm and 5 am. The smallest HF was observed between midday and 2 pm. LF/HF peaked between 6 and 9 am as well as between 4 and 6 pm with the smallest values between midnight and 5 am. Sex adjustment was of no significance. In healthy subjects, HF and LF/HF have circadian pattern. Evaluation of all 5-minute intervals of 24-hour period seems to be a precise method of heart rate variability analysis.
Department of Internal Medicine, University School of Medicine in Lublin, 20-081 Lublin, Staszica 16, Poland. anbil@eskulap.am.lublin.pl
Andrzej
A
Bilan
Agnieszka
A
Witczak
Robert
R
Palusiński
Wojciech
W
Myśliński
Janusz
J
Hanzlik
D000204:Activity Cycles / Q000502:physiology; D000328:Adult; D002940:Circadian Rhythm / Q000502:physiology*; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors