[The specific nature of the nonuniformity of muscle tensions in different sections of the heart under the action of inotropic factors].

In anesthetized dogs, changes of tensions due to the effect of CaCl2 solution were studied in the left ventricle's wall and the heart apex. Hemodynamic parameters, ECG and intramural tension were recorded. The tension forms looked different in the wall and the apex at normal cardiac contractions; they changed in different ways under the effect of inotropic factors. The latters could induce three types of the amplitude non-uniformity in the left ventricle's wall and in the apex, depending on the drug and its dose. The non-uniformity type for a separate heart is specific in respect to administered drug. The non-uniformities at large doses of inotropic factor exceeding normal physiological levels, are regarded as an additional mechanism of the heart stability under considerable loads.