Dynamic Change of Mitral Annular Geometry and Motion in Ischemic Mitral Regurgitation Assessed by a Computerized 3D Echo Method

OBJECTIVE: In patients with ischemic mitral regurgitation (IMR), we assessed dynamic changes in mitral annular geometry and motion during the cardiac cycle, and examined their association with the severity of IMR, using our computerized three-dimensional (3D) echo method. METHODS: Real-time 3D echo was performed in 12 normal controls and 25 patients with IMR. The saddle-shaped annulus was reconstructed in every 3D volume/frame during a cardiac cycle. For each 3D volume/frame, we assessed the mitral annular area (MAA) and the annular contraction that was expressed as the percentage of the largest MAA accounted for by the change in MAA from largest to smallest calculated value. RESULTS: In IMR patients, the minimum MAA occurred in late-systole, while it occurred in early-systole in the controls. IMR patients had a larger minimum MAA (6.7 ± 1.3 vs. 3.6 ± 0.8 cm², P < 0.001) and reduced annular contraction (23.0 ± 6.5 vs. 42.6 ± 7.0%, P < 0.001) when compared to controls. Both minimum MAA and annular contraction had significant correlations with IMR severity (r = 0.67 and r = 0.78, P < 0.001 for both). CONCLUSION: The contraction of the dilated mitral annulus occurred in late-systole in patients with IMR. The alterations of annular geometry and motion may be associated with the development of IMR.