Click on image to view larger version.

Figure 4 Paired comparison of change in left ventricular end-systolic elastance (E_es) induced by dobutamine determined by noninvasive estimation versus the directly assessed value derived from invasive pressure-volume loops. The noninvasive method provided a good estimate of E_es (n = 29, r = 0.88, p < 0.0001, with a regression slope and intercept that were not statistically different from 1.0 and 0, respectively. E_es(sb) = change in left ventricular end-systolic elastance by single-beat technique.