1986 年 24 巻 7 号 p. 511-516
A recent analysis of spontaneous heart rate variability has shown it to be related to three major physiological factors: quasioscillatory fluctuations thought to arise in blood pressure control from variable frequency oscillations due to thermal regulation and respiration.
In the present paper we identified a multivariate autoregressive model and applied the spectral analysis method to R-R intervals and blood pressure data from resting five subjects. Blood pressure was measured at the aortic arch.
The R-R interval spectra show three peaks of about 4.4 beats, 2.5 beats and about 10 beats. The spectra of systolic blood pressure (SBP) show the peaks of about 4.5 beats, 2.6 beats and 31 beats. The spectra of diastolic blood pressure (DBP) show peaks of about 4.6 beats, 2.3 beats and 21 beats. So R-R intervals and blood pressure are interconnected.
Moreover, integrated relative power contribution of R-R intervals, SBP, and DBP are presented. We also propose new spectra concerning with the relative power contribution. We show that the fluctuations of SBP have the influence upon R-R intervals at the rate of 24% at frequency of 4.4 beats by the relative power contribution. The fluctuations of DBP have influenced the R-R intervals at the rate of 13% at the same frequency. Residual 63% of fluctuations of R-R intervals are self-fluctuations.
In this paper, the results of atropine injection into a patient are also reported.
These analytical methods are useful for the biomedical multivariable feedback control-system.