Objective: Functional mitral regurgitation (FMR) occurs commonly in patients with dilated cardiomyopathy (DCM). The aim of this study was to compare the roles of Left Ventricle(LV) dyssynchrony and geometric parameters of mitral apparatus as determinants of FMR in patients with DCM.
Methods: Fourteen DCM patients without FMR and 15 DCM patients with FMR (ERO = 0.11 ± 0.029 cm
2
) were enrolled. Effective regurgitant orifice (ERO) area and tissue Doppler-derived dyssynchrony index (DI: the standard deviation of time to peak myocardial systolic contraction of eight segments) were measured. The estimated DIs were corrected by the cycle length (CL) of each patient (cDI (%) = DI/CL*100). Using real-time 3D echocardiogrphy, mitral tenting area (MVT) and the degrees of displacement of anterior (APMD) and posterior (PPMD) papillary muscles were estimated. All geometric measurements were corrected (c) by the height of each patient.
Results: There was no significant (p > 0.05) difference in LV Ejection Fraction and cLVEDV between two patient groups. cDI, cMVT, cAPMD and cPPMD significantly (p < 0.05) increased in the patient with FMR comparing with those in patients without FMR. cDI (r = 0.42), cMVT (r = 0.74), cAPMD (r = 0.63) and cPPMD (r = 0.64) showed significant (p < 0.05) correlations with ERO. cMVT was found to the strongest independent predictor of ERO with multivariate regression analysis, whereas cDI did not enter into the model.
Conclusions: The degree of MV tenting rather than LV dyssynchrony was found to be the main determinant of FMR in DCM. However LV dyssynchrony also has a minor independent association with FMR.
Role of Dyssynchrony on Functional Mitral Regurgitation in Patients with Idiopathic Dilated Cardiomyopathy: A Comparison Study with Geometric Parameters of Mitral Apparatus