[Is the quotient: systolic peak pressure/end-systolic volume a useful parameter in the assessment of left ventricular...

The quotient: peak systolic pressure/end-systolic volume (SP/ESVI) has been proposed as a parameter of LV function and as a substitute for the slope k of the end-systolic pressure-volume relation (P-Ves), because SP/ESVI is much easier to obtain. Therefore, the relation between SP/ESVI and k and the relation between SP/ESVI and ejection fraction (EF) were investigated. In 18 patients P-Ves was obtained after vegetative blockade (1.5 mg atropine and 0.15 mg/kg propranolol) from three LV angiograms at three different afterloads (control, isosorbide dinitrate, methoxamine). - SP/ESVI and slope k showed a moderate correlation: SP/ESVI = 0.50k + 2.35; r = 0.76. SP/ESVI and EF were correlated best in an exponential way: SP/ESVI = 0.267 X e0. 045EF ; r = 0.82.- An essential disadvantage of the quotient SP/ESVI resides in the fact, that the P-Ves line has varying intercepts on the abscissa. Secondly, any quotient may belong to several P-Ves lines. The quotient SP/ESVI may be used only with caution and under specific conditions as a substitute of the slope k of the P-Ves.