Studies Made by Simulating Systole at Necropsy. V. Estimation of the Contour of the Left Ventricular Ejection Curve by an Adjusted Integration of the Aortic Blood Pressure Curve

Abstract

Systole was simulated by injecting blood or water into the aorta of cadavers after producing a physiological diastolic pressure by an infusion into the femoral artery. The cardiac output of each instant of systole was recorded, as was the blood pressure in the root of the aorta, by optical systems. Thus these 2 curves could be compared. By means of an adjusted integration the contour of the cardiac ejection curve can be estimated from that of the aortic blood pressure curve. The accuracy of the method was tested by comparing the estimated cardiac ejection curve with that recorded in 75 simulated systoles. In over 80% the agreement was excellent. If the total stroke volume is determined by some other means the cardiac output at each instant of systole can be calculated from the contour of the aortic pressure curve with reasonably good accuracy.