Background: Mitral regurgitation (MR) is an independent predictor of morbidity and mortality in chronic heart failure. Determinants of this ‘functional’ MR are complex. Hemodynamic, left ventricular regional function and geometry but also dyssynchrony and mitral annulus size are involved. We sought to assess the relative influence of heart dimensions, myocardial contractility and ventricular dyssynchrony on MR severity.

Methods and results: 100 consecutive chronic heart failure (CHF)-patients were studied by echocardiography. We measured LV dimensions, left atrial and mitral annulus sizes, filling pressures, myocardial longitudinal and transversal contractility and dyssynchrony using 2-D strain abilities. MR was quantified by the regurgitant volume (RV) calculated by the Doppler- and PISA-methods. In the bivariate regression analysis, RV correlated with: mitral annulus diameter (R = 0.63, p < 0.001), LV volumes (p = 0.004), estimated filling pressures (E/Ea p = 0.003), Longitudinal strain (2D-S) of the mid-lateral wall (%) (p = 0.01) and time-to-peak lateral 2D-S (p < 0.001). RV did not significantly correlated with longitudinal strain rate and radial (transversal) strain or strain rate peaks. Mitral annulus diameter, time-to-peak of 2D-S and E/Ea-ratio predicted the degree of the MR

Conclusion: MR in CHF-patients are multifactorial. Using 2D-strain, we demonstrated that longitudinal contractility and dyssynchrony influenced more the degree of MR than radial (transversal) ones. Also strain rate (relative load independence) analysis demonstrated that loading condition should be considered with a great caution when assessing a MR in the CHF population.