Effect of Plethora and Hemorrhage on Left Ventricular Volume and Pressure

Abstract

By combining conventional methods for recording pressures from the left ventricle and pleural cavity with a new procedure for estimating end-diastolic volume (EDV) and end-systolic volume (ESV) of the left ventricle it was found in the closed-chest dog that plethora increased EDV, ESV and stroke volume while hemorrhage had the opposite effect. There were linear relationships between EDV and ESV, and between EDV and stroke volume. There was little change in left ventricular "effective" end-diastolic pressure when the EDV changed over a wide range, beginning with the smallest EDV consistent with life; but after a certain large EDV had been reached, large increases in effective end-diastolic pressure were associated with little or no further increase in EDV.