Dimensional analysis applied to the evaluation of LV function in the presence of mitral regurgitation: computer simulations

Traditional indices of LV function do not accurately reflect the true contractile state in mitral regurgitation (MR) because the low impedance systolic MR flow allows the LV ejection fraction (EF) to remain normal despite LV contractile dysfunction. It would therefore be useful to have method for predicting the EF if MR is eliminated from a given ventricle assuming contractility and blood pressure do not change. A computer model was used to simulate ventricular hemodynamics in the presence and absence of MR. The data were then analyzed using dimensional analysis, a technique for combining multiple variables into a compact formulation. Dimensional analysis revealed that the data could be collapsed into a single equation. This formulation potentially permits ejection fraction calculations that are corrected for the degree of MR from a specified set of ventricular function indices. Validation in patients is the next step.