Mitral Annulus Flattens in Ischemic Mitral Regurgitation: Geometric Differences Between Inferior and Anterior Myocardial Infarction: a Real-time 3-dimensional Echocardiographic Study

Background: New surgical strategies to restore the saddle shape of the mitral annulus are expected to increase annuloplasty effectiveness. Preoperative and postoperative configuration of the curved annulus, however, is difficult to quantify with 2-dimensional echocardiography. We sought to investigate the geometric deformity in the mitral annulus in ischemic mitral regurgitation (MR), comparing inferior and anterior myocardial infarction (MI) with the use of a custom quantitation software system with transthoracic 3-dimensional echocardiography.

Methods And Results: We performed real-time 3-dimensional echocardiography in 23 patients with ischemic MR attributable to inferior MI or anterior MI and in 10 controls. Three-dimensional data were cropped into 18 radial planes, and we manually marked the annulus in mid systole. Three-dimensional annular images were reconstructed, and annular circumferences, areas, and heights were quantified. Annulus was significantly more dilated and flattened in ischemic MR than in controls and was further deformed in anterior MI as compared with inferior MI (control: circumference 9.9+/-0.7 cm, area 9.6+/-0.5 cm2, height 5.0+/-0.7 mm; inferior MI: circumference 11.5+/-1.2 cm [P<0.01 compared with control], area 11.4+/-2.0 cm2 [P<0.05 compared with control], height 3.5+/-1.6 mm [P<0.05 compared with control]; anterior MI: circumference 14.2+/-2.4 cm [P<0.0001 compared with control, P<0.05 compared with inferior MI], area 13.7+/-2.8 cm2 [P<0.01 compared with control, P<0.05 compared with inferior MI], height 1.7+/-1.5 mm [P<0.0001 compared with control, P<0.05 compared with inferior MI]).

Conclusions: Mitral annulus flattens in ischemic MR. Deformity of the mitral annulus was greater in anterior MI group than in the inferior MI group.