Abstract 17399: Twisting Motion of the Mitral Complex Assessed by Real-time 3-dimensional Echocardiography: Comparison between Normal Subjects and Functional Mitral Regurgitation.
Introduction: Left ventricular (LV) torsion has been reported. However, less is known about twisting motion of the mitral complex concomitant with ventricular torsion.
Hypothesis: The aim of our study was to assess the hypothesis that the mitral complex has twisting motion, and examine the contribution of disturbed twisting motion of the mitral complex to the severity of functional mitral regurgitation (MR), using real-time 3-dimensional echocardiography (RT3DE).
Methods: RT3DE was performed in 14 normal subjects and 17 patients with functional MR caused by global LV dysfunction. The short axis views at the basal level and the papillary muscle (PM) level were obtained from 3D volume data set using TomTec 3D software. Angle α between the anterior-posterior (AP) plane and the commissura-commissura (CC) plane at the basal level (figure) in 3D space was measured at both end-systole and end-diastole. Angle β between the AP plane and the PM plane at the PM level was measured as well (figure). The CC-PM angle was calculated as β-α at both end-systole and end-diastole. The MR severity was assessed by PISA method.
Results: In normal subjects, the CC-PM angle increased at 7.3±4.4 degree during systole, suggesting the mitral complex has twisting motion. In functional MR, the change of CC-PM angle during systole was smaller than the normals (0.5±10.9 degree, p<0.05), and did not correlate with LV ejection fraction. The change of the CC-PM angle during systole did not correlate with the MR severity, but angle β at end-diastole significantly correlated with the MR severity (r=-0.52, p<0.05).
Conclusions: The mitral complex had twisting motion during systole. In patients with functional MR, the MR severity was associated with the angle of papillary muscle at end-systole, rather than decreased twisting motion of the mitral complex during systole.
- © 2010 by American Heart Association, Inc.