[The theory of regulation of the contraction force of the heart muscle]. / K teorii reguliatsii sily sokrashchenii serdechnoi myshtsy.

A model of rhythmoinotropic phenomena in the heart muscle is elaborated. Kinetics of calcium flowing in intracellular pools of cardiomyocytes is described by differential equations. Dimensionless values (portions) serve as equation coefficients. They determine calcium kinetics in the pools and finally its amount is liberated into the myoplasm during stimulation. Proceeding from physiological considerations for portions there are given laws connecting portion values with intervals between stimuli. S-pool introduced into the model is principally new, it permits quantitative description of the effects of postextrasystolic potentiation and paired stimulation. Introduction of S-pool into the model changes the commonly accepted concept of calcium recirculation in the pools, and apparently, makes it possible for the first time to model all the results obtained on isolated myocardium of warm-blooded animals.