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.