Critical evaluation of indices of myocardial contractility derived from the isovolumic phase of contraction.
The accuracy, sensitivity and reproducibility of several isovolumic force-velocity indices of myocardial contractility were compared. Contractile element velocity was calculated using both two-element (total pressure) and three-element (developed pressure) models of cardiac muscle. While all indices demonstrated comparable sensitivity to inotropic state, only Vmax using developed pressure was independent of preload and appeared to be a useful index of the myocardial contractile state.
D000818:Animals; D003201:Computers; D004285:Dogs; D066298:In Vitro Techniques; D008433:Mathematics; D008962:Models, Theoretical; D009200:Myocardial Contraction; D016276:Ventricular Function