[Features of contraction of various sections of the left ventricle of an intact heart upon the action of inotropic factors]

Abstract

In anesthetized dogs, the effects of adrenaline and CaCl2 were studied by means of measuring intramural tension in the left ventricle wall (LV) and in the apex. The inotropic effect involved an increase in the ratio between the velocity of the tension growth in isovolumic phase and the maximum tension of this contraction, the ratio increasing more slowly in the apex than in the LV. This can be due to that the inotropic factors induce a greater growth of intramural tension in the apex than in the LV.