[Effect of adrenaline on rat atrial and ventricular chronoinotropy]

The atria and ventricles were shown to differ from each other in: temporal course of contractions, relations between the strength of contractions and the interstimuli interval, resting potentiation, transitional processes after intermissions, character of response to adrenaline. For the first time the adrenaline was shown to annihilate differences in restitution processes occurring in atria and ventricles. The differences of responses in atria and ventricles seem to be due to concentration of endogenous catecholamines which modulate the electromechanical coupling of the rhythmically working myocardium.