We compared maximal acceleration of aortic blood flow (aortic Amax), calculated from maximal aortic velocity obtained with a conventional echo-Doppler machine with the invasive inotropic index left ventricular end-systolic pressure/left ventricular end-systolic volume (LVESP/LVESV) ratio and left ventricular ejection fraction (LVEF). Continuous wave (CW) and pulsed wave (PW) Doppler aortic blood flows were recorded from the apical view in 16 patients (age, 62.3 +/- 6.4 years) within 24 h of left-sided catheterization. The theoretical exponential relationship between LVEF and LVESP/LVESV was confirmed in our study population (r = 0.92; p < 0.0001). The relationship between aortic Amax determined either by CW or PW and LVESP/LVESV was linear (r = 0.92 and 0.93, respectively, p < 0.001), whereas the relationship between aortic Amax and angiographic LVEF was exponential (PW: r = 84; CW: r = 0.85; both p < 0.001). We conclude that (1) aortic Amax, derived from maximal velocity obtained with a conventional machine, can be used as an index of left ventricular systolic function, and (2) PW as well as CW Doppler signals can be used for this calculation.