Estimation of Coronary Reserve by Dynamic Electrocardiography

A method of detection of coronary reserve (CR) for the effective estimation of the functional state of patients with coronary heart disease is discussed. To verify CR estimation by loading tests in subjects with pronounced signs of myocardial ischemia in the electrocardiogram, we examined the stationary heart rate (HR) level as a function of the loading power in each subject. These functions contained intervals of linear and nonlinear changes. In patients with stable stenocardia, the minimum daily HR and the threshold HR that characterizes reaching of the anaerobic threshold by myocardium loci were always in the domain of linear changes. A pathophysiologically substantiated index of coronary reserve was advanced. Values of this index of over 60, 60–35, 34–20, and below 20% correspond to functional classes I, II, III, and IV of stenocardia, respectively.