Background: Annular geometry and motion in functional ischemic mitral regurgitation are incompletely understood. Three-dimensional echocardiography demonstrates saddle-shaped annular geometry, but standard methodology does not enable quantification of annular motion. Therefore, a novel technique using three-dimensional echocardiography and computer software was used to characterize alterations in mitral annular geometry and motion in patients with ischemic mitral regurgitation.
Methods: We developed a computer program to reconstruct the mitral annulus based on spatial coordinates from three-dimensional echocardiography. Data were obtained at end-diastole and end-systole in 7 patients with ischemic mitral regurgitation and 5 normal control subjects. Mitral annular motion was quantified by calculating the displacement area of the annulus between end-diastole and end-systole.
Results: Comparison of ischemic mitral regurgitation and control patients revealed differences in annular geometry and motion at end-diastole. Annular perimeter was greater in ischemic mitral regurgitation patients (10.7 +/- 0.7 cm versus 8.6 +/- 0.2 cm in control group; p < 0.03), with increased intertrigonal distance in ischemic mitral regurgitation patients (2.8 +/- 0.3 cm versus 2.1 +/- 0.1 cm; p < 0.06). These changes resulted in increased annular orifice area in ischemic mitral regurgitation patients (9.1 +/- 1.2 cm2 versus 5.7 +/- 0.3 cm2; p < 0.03). Ischemic mitral regurgitation patients had altered annular motion, with reduced movement of the posterior annulus (5.4 +/- 0.7 cm2 versus 8.7 +/- 1.1 cm2; p < 0.03).
Conclusions: Computer analysis of data obtained from three-dimensional echocardiography demonstrates altered annular geometry and motion in patients with ischemic mitral regurgitation. Patients with ischemic mitral regurgitation have annular dilatation, with an increase in anterior and posterior annular perimeters; this is accompanied by an increase in the intertrigonal distance and restriction of annular motion.