Three-dimensional assessment of mitral valve annulus dynamics and impact on quantification of mitral regurgitation.

Abstract

To assess mitral annulus dynamics in primary and secondary mitral regurgitation (MR) with 3-dimensional transesophageal echocardiography (3D TEE) and the impact on MR quantification. One hundred and twenty-three patients with moderate and severe MR (63 ± 11 years, 78 males) and 29 controls (59 ± 15 years, 19 males) were evaluated. Functional MR (FMR) was present in 31 patients, fibroelastic deficiency (FED) in 52 and Barlow's disease (BD) in 40. Annular geometry was assessed with 3D TEE. The annulus height to commissural width ratio (AHCWR) was calculated to characterize the saddle shape of the mitral annulus. MR was graded as holo- or late-systolic. Effective regurgitant orifice area (EROA) and regurgitant volume (Rvol) were measured with 2D and 3D TEE. FMR, FED, and BD patients had larger mitral annular dimensions than controls. BD patients showed the largest dimensions whereas FMR and FED were similar. Early-systolic saddle shape was flatter in FMR whereas, in FED and BD, it was more pronounced. Annular dynamics were reduced in FMR but increased in FED and BD, compared with controls. In BD patients, 3D EROA and Rvol were larger compared with 2D TEE. In BD patients with late systolic MR (48%), 3D Rvol was larger than 2D Rvol. Univariate regression analyses showed significant correlations between relative change of annulus height (β = 0.43, P = 0.011) and AHCWR (β = 0.40, P = 0.024) with 3D Rvol in FED and BD. The mitral annulus is enlarged and stiff in FMR patients, whereas in FED and BD it is characterized by excessive dynamicity during systole. Enhanced annular dynamics leads to significant changes in grade of MR measured by 3D TEE particularly in those with late onset MR.