抄録
To investigate the role of the peripheral effector for the generation of heart rate variability, the relationship among the P-P, R-R. P-R, and R-P intervals were compared on five healthy male subject in the supine position. During supine rest, electrocardiogram was monitored, and P-P, R-R, P-R, and R-P intervals were measured. Power spectral densities (PSD) were esti-mated by using direct method for successive 256 intervals. PSDS were integrated at the low (PSDLF ; 0.05-0.15 cycle/beat) and high (PSDHF ; 0.20-0.40 cycle/beat) frequency bands. Mean interval times of P-P, R-R. R-P, and P-R intervals were 827±40, 827±40, 657±34, 170±19 msec, respectively. PSDLFS of P-P, R-R, R-P, and P-R intervals were 15677±2771, 15566±2815, 15345±2767, 1491±255 msec2/c/b, respectively. PSDHFS of P-P, R-R, R-P, and P-R intervals were 13289±3602, 12918±3897, 12558±3630, 2758±517 msec2/c/b, respectively. The PSD of P-R intervals showed white noise. These results might suggest that the periodic fluctuation would be formed at or above the sinoatrial node.
