EVALUATION OF MYOCARDIAL CONTRACTILITY IN MAN

In 53 patients studied at cardiac catheterization, the relationship between the maximal rate of rise of the left ventricular pressure and the integrated isovolumetric stress was observed to be an excellent index of contractility. A clearer separation of patients with evidence of myocardial disease was possible with this index than with other parameters assessed. The ejected fraction (fiber-shortening) was noticed to be an inverse function of the peak systolic tension (afterload) as expected from extensive experimental work. The highest reciprocity was observed in patients with myocardial disease, indicating the probable deleterious effect of an increasing peripheral resistance in this type of patient. End-diastolic stress was found to be significantly higher in patients with evidence of myocardial damage, due to a relatively thinner myocardial wall in this group. © 1969.