Noninvasive determination of the left ventricular end-systolic pressure.

To find a noninvasive method for estimating left ventricular end-systolic pressure, 40 patients were studied during cardiac catheterization. Arterial pressure was taken directly from the ascending aorta. Carotid pulse tracing and measurement of blood pressure by cuff sphygmomanometry were taken simultaneously. The tracings were calibrated and left ventricular end-systolic pressure was estimated directly and indirectly. Simple linear regression analysis gave the equations: (1) left ventricular end-systolic pressure direct = 0.56 left ventricular end-systolic pressure indirect + 43.8 (r = 0.61, P = 0.00004), and (2) left ventricular end-systolic pressure direct = 0.39 systolic arterial pressure indirect + 48.8 (r = 0.62, P = 0.00002). To test the accuracy of the technique the study was continued in 40 patients. Left ventricular end-systolic pressure was also estimated by the 2 equations. Left ventricular end-systolic pressure direct was correlated with left ventricular end-systolic pressure estimated by the 2 equations and there was no statistical difference. This noninvasive technique is a bedside method for clinical measurement of left ventricular end-systolic pressure.