[The use of 2-component myocardial contraction for assessing the mechanism of action of inotropic substances].

The possibility of using two-component contraction of the myocardium to evaluate the mechanisms of action of cardiotropic pharmacological agents was studied. Caffeine, ouabain, low-natrium solution, varapamil, nifedipine and BAY K-8644 were used. It was concluded that the analysis of contraction component amplitude dynamics makes it possible to determine the effect of the pharmacological agents on the interrelated mechanisms of the delivery of Ca2+ into the myoplasm of cardiomyocytes from sarcoplasmic reticulum and through sarcolemma during a single cardiac cycle.