自律神經隨著作息具24小時週期性,HRV中之副交感指標HF及交感/副交感平衡指標LF/HF都在晚上呈現最大值, 交感指標LF的最大值發生於清晨5-9AM及下午4-6PM; HF的最大值發生於深夜11PM – 5AM
Circadian rhythm of spectral indices of heart rate variability in healthy subjects.
J Electrocardiol. 2005; 38(3):239-43 (ISSN: 0022-0736)
Bilan A; Witczak A; Palusi?ski R; My?li?ski W; Hanzlik J
Department of Internal Medicine, University School of Medicine in Lublin, 20-081 Lublin, Staszica 16, Poland. anbil@eskulap.am.lublin.pl

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.