AORTIC PRESSURE LOADING IN DOGS WITH MYOCARDIAL INFARCTION

Pressure function curves of the left ventricle were carried out in dogs with myocardial infarction produced by coronary ligation, using the technique of inflating a balloon in the ascending aorta. Under base-line conditions, the pressure function curve in animals with infarcts was depressed compared to sham operated animals. Infusion of the inotropic agents acetylstrophanthidin and isoproterenol elevated the pressure function curves in both groups of animals, but the response to isoproterenol was greatly reduced in animals with infarcts. These results show that pressure loading of the left ventricle may be used to reveal defects in ventricular performance in dogs with experimental myocardial infarction, in the absence of overt heart failure, and that infusion of inotropic agents such as isoproterenol may further accentuate this defect. © 1969.