Kehl DW, et al. – The physicians distinguished cases of flail mitral leaflet correlated with only mild or moderate mitral regurgitation (MR) and evaluated their echocardiographic features and clinical outcomes. It was considered that the flail mitral leaflet is not synonymous with severe MR and can be correlated with only mild or moderate MR. Moreover, patients with flail mitral leaflet and only mild to moderate MR were clinically stable. Therefore, an integrated, multiparametric technique should be used to assess MR severity, even in the presence of a flail mitral leaflet.