[Experimental study of the output characteristics of the left heart ventricle]

A method is suggested of evaluating the cardiac internal hydraulic resistance R0 and maximal blood flow at zero post load Q0. R0 in intact dogs is 11.9 mm/Hg/l/min and Q0 is 27.1 l/min. In the condition of acute cardiac insufficiency and under the effect of large adrenaline doses these parameters were, respectively, 8.8 mm Hg/l/min, 7.0 mm Hg/l/min and 36.9 l/min, 38.8 l/min. The reducing of of R0 reflect the reduction of rigidity of the myocardial wall, and the increase of Q0 reflects the increase of the cardiac muscle inotropism connected with the compensatory increase of the catecholamines level in blood.