ABSTRACT
This study was devoted to the problem of homeostatic stability loss caused by myocardial ischemia, induced by stress testing. It involved 55 patients with different variants of coronary heart disease and 15 practically healthy volunteers as controls. Routine bicycle ergometry and nonstop monitoring of the cardiac-interval duration were conducted simultaneously. The systemic homeokinetic state was evaluated by means of cardiac rhythm entropy dynamics analysis in a multidimensional space of existence. Determined chaos was shown to be the main property of these dynamics in all cases. The original method of measuring the cardiac rhythm entropy chaotisity level is presented. It is suggested that the newly revealed phenomenon of a sharp rise in the cardiac entropy trajectory chaotisity level and followed by a decrease, which happens in the multidimensional phase space, may be used as an additional criterion of myocardial ischemia development for the verification of dubious stress-testing results.
Subject(s)
Myocardial Ischemia/physiopathology , Nonlinear Dynamics , Adult , Case-Control Studies , Coronary Circulation/physiology , Entropy , Exercise Test , Homeostasis , Humans , Male , Middle Aged , Time FactorsABSTRACT
The new approach to intraoperative hemodynamics disorders prognostication which caused of inadequate anaesthesiological protection is presented in this research. Hemodynamic parameters stability both with systemic homeokinesis state were investigated in 28 patients with various surgical diseases. Their surgical operations were carried out with either of combinatory inhalation anaesthesia (halothane and neuroleptics) or noninhalation neuroleptnarcasis with ketamine. Instability of homeostatic regulation was controlled with special original analysis of cardiac rhythm entropy dynamics chaotisity in multidimensional faze space of existence. It is established that numerical criterion of cardiac rhythm chaotic state degree exceeds the intended acceptable level 5-10 minutes before clinical signs of hemodynamics instability developing in all inadequate anaesthesiological protection cases.
