The dynamics of chaotic states of cardiac rhythm
.P. Agulova, V.T. Sarychev, K.A. Tsiplukhin
Cardiology Institute of Tomsk Research Centre of Russian Academy
of Medical Sciences,
Siberian Phisical and Technical Institute, Tomsk, Russia
Dynamics of chaos and information amount in the signal in every-day recording of human cardiac rhythm at rest was studied. R-R intervals (time intervals between neighbouring R-waves of electrocardiogram) were recorded. The study was carried out within 22 days under standardized conditions. Chaos level (E) was estimated on the base of the function of density of oscillations' distribution, which maximum entropy method was founded [1]. Besides information amount and descrepancy by Kullback were estimated.
Many-days' dynamics of E and I produces oscillatory processes
with similar periods (T) and phases (f).
.
The distinctive features of entropy were resistance to casual influences and regulation oscillations in comparison with overwhelming majority of physiological indexes. It is of key importance for prognosis of alive systems' status. Kullback's descrepancy was of more variable but regular too.
Transitory (within 150-200 seconds) dynamics of E and I studied
using sliding window produces wave-form processes too.
This research was supported by Russian Fundamental Research
Fund (Grant 93-012-1065).