[The end-systolic pressure-volume relationship in the assessment of left ventricular function (author's transl)]

This investigation was undertaken to determine whether the left ventricular (LV) end-systolic pressure and end-systolic volume, as measured under clinical conditions, are linearly correlated and whether the slope of the end-systolic pressure-volume relationship (P-Ves) is a meaningful parameter in the assessment of left ventricular function. The studies were performed in twelve patients (eleven with coronary artery disease and one with congestive cardiomyopathy) during which autonomic reflex responses were minimized by propranolol (0.15 mg/kg i.v.) and atropine (1 mg i.v.). Three left ventricular angiograms (at rest, after 10 mg isosorbide dinitrate and during an infusion of 2 mg/min methoxamine) were obtained from which the three respective P-Ves data points were calculated and subjected to linear regression analysis (r greater than or equal to 0.96). The slope k of the linear P-Ves relation correlated most closely with the resting ejection fraction (EF) as an exponential function (r = 0.94). The end-systolic pressure could be interchanged with the peak systolic pressure which is more easily obtained. The theoretical end-systolic volume at end-systolic pressure = 0 (V0) was not related to the resting ejection fraction. Post-extrasystolic potentiation, resulting in an acute inotropic incrementation, shifted the P-Ves toward similar volumes and steepened its slope.