Abstract 3240: Geometric Differences of Mitral Apparatus Between Ischemic and Dilated Cardiomyopathy With Significant Mitral Regurgitation: Three-Dimensional Analysis With Multislice Computed Tomography
Background: The three-dimensional (3D) geometry of the mitral apparatus accompanied by regional or global LV dilatation has not been well investigated. We assessed 3D geometric differences of the mitral apparatus in patients with significant mitral regurgitation caused by ischemic cardiomyopathy (ICM-MR) and idiopathic dilated cardiomyopathy (DCM-MR) using multislice computed tomography (MSCT).
Methods: We obtained volumetric images of mitral apparatus in 13 patients with ICM-MR caused by inferior or posterior myocardial infarction and 11 patients with DCM-MR. The novel original software was used to crop the 3D data into 16 planes and the mitral annulus, leaflets, and tips and bases of papillary muscles were marked in end systole. In reconstructed 3D images, we measured tenting volume in medial and lateral site (medial and lateral half of the mitral annulus) and tethering distances of both papillary muscles (PMs).
Results: In ICM-MR, posterior PM tethering distance was significantly longer than anterior PM tethering distance (35±6 mm vs. 27±5 mm, p<0.001) and medial tenting volume was significantly greater than lateral tenting volume (1.52±0.82 ml vs. 1.27±0.50 ml, p<0.05). In DCM-MR, there were no significant differences between posterior and anterior PM tethering distances and between medial and lateral tenting volume. In all patients, the anterior and posterior PM tethering distance correlated with the lateral and medial tenting volume, respectively (r=0.87, p<0.001 and r=0.69, p<0.001).
Conclusions: We clearly demonstrated 3D asymmetrical deformity of mitral apparatus in ICM-MR compared with DCM-MR using novel software with MSCT.