[Relation of systemic and coronary fractions of left ventricle output during administration of vasoactive substances]

Against the background of increased arterial pressure, administration of noradrenaline and adrenaline increased the systemic fraction of cardiac output in 53 and 59 per cent of cases, resp., and decreased it in the rest of tests. Administration of mesatone decreased the systemic fraction in 75 per cent of cases. The coronary fraction was invariably increased. The coronary to systemic fractions ratio revealed significance of one or another fraction for the left ventricle output. The group with a decreasing systemic fraction on administration of each substance revealed a hyperbolic relationship between the ratio an shifts of the left ventricle total output. Administration of noradrenaline and mesatone induced a transition from a reduction of the left ventricle total output to its enhancement at values of the ratio less than -1, whereas in case of adrenaline-at values less than -5. No interrelationship was found between the left ventricle total output and its coronary fraction and the arterial pressure increment induced with adrenaline and noradrenaline.