Differences in fractal structure of adult heart rate fluctuation between successive rapid eye movement sleeps: case report.

ABSTRACT

The dynamics of fractal structures of heart rate (HR) fluctuations in successive rapid eye movement sleeps (REMS) was investigated in a healthy male. Fractal analysis using a purposely-devised method was carried out at 10-min time series of HR, which were being recorded simultaneously by an electroencephalogram at night. Scaling relationships showed three slopes (alpha(s)). The mean alphas below one cross-over point (< 6.0 s), mean alpha(m) between two cross-over points, and mean alpha1 above another cross-over point (> 12.0 s) during REMS changed from 2.0, 1.0, and 0.3 in the third cycle to 2.0, 0.9, and 1.2 in the fourth cycle. The present study demonstrates the differences in multiscaled fractal structures of HR fluctuations between the successive REMS in a particular case.