Hemodynamics "paradoxes" in arterial hypertension patients
as the result of interfunctional ties nonlinearity
L.P. Agulova, I.Yu. Baiko
Cardiology Institute of Tomsk Research Centre of Russian Academy
of Medical Sciences, Tomsk, Russia
There is no reason to treat circulation as a linear system. Every-day (within a month) standardized studies of systemic hemodynamics by the method of tetrapolar rheography in 21 patient with mild and moderate essential hypertension testify to this fact. All the studied patients,instead of expected direct and revers linear dependences, demonstrated "paradoxical" ones: in some values of stroke heart (SH) and peripheral vascular resistance (VR) arterial pressure (AP), sistolic and diastolic, increased and in further increase of these values AP decreased, then - icreased and decreased again - up to the definite limit. As a result, at the same patient exhibited various and difficult for explanation combination of AP, SH and VR. The dependences received are approximated by polynom not lower than the 3-rd degree.
Taking into account the oscillatory character of all the biological processes we can suggest that the nonlinearity mentioned is the result of not complete synchronization of hemodynamic parameters. So, patients with high and moderate synchronization (sinchronizations coefficient K ;SPMgt; 0.5 ) demonstrated polinom of the 6-8-th degree in 35% of cases, and patients with low sinchronization (K;SPMlt; 0.05) - in 53 coefficient was estimated by the comparison of periods and phases of weekly rhythmths of hemocirculatory characteristics mentioned.
The processes in the organism should not be very much synchronized and not very much disconnected. Either of this leads to the restriction of adaptation ability of biosystem, on the one hand, and the ability of its regulation by therapeutic action, on the other hand. This is confirmed by the tendency to the increase in functions' synchronization (nonlinearity decrease) disovered by as in disease progress. Nonlinearity is likely to play the role of amortization device maintaining the necessary inertia in the system of hemodynamic parameters' regulation. The search in optimal values of non-linearity is, in our opinion, a perspective direction of biomedical studies.