Quantitation of mitral valve tenting in ischemic mitral regurgitation by transthoracic real-time three-dimensional echocardiography
Nozomi Watanabe, MD, FACC*,*,
Yasuo Ogasawara, PhD ,
Yasuko Yamaura, MD*,
Takahiro Kawamoto, MD*,
Eiji Toyota, MD*,
Takashi Akasaka, MD* and
Kiyoshi Yoshida, MD, FACC*
* Department of Cardiology, Kawasaki Medical School, Kurashiki, Japan
Department of Medical Engineering and Systems of Cardiology, Kawasaki Medical School, Kurashiki, Japan
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Figure 1 Three-dimensional (3D) volumetric image was automatically cropped into 18 equally spaced radial planes. We manually marked the mitral annulus and leaflets in each cropped plane in mid-systole. From these data, 3D images of the mitral leaflets and annulus were reconstructed.
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Figure 2 Three-dimensional (3D) images of mitral annulus and leaflets in a normal subject. (A) Anatomical 3D image (views from two directions). Mitral annulus appeared as a nonplanar "saddle shape." Mitral leaflets appeared almost flat, with a little tethering into the left ventricle. (B) Actual 3D tenting image. The annular shape was approximated for the 3D quantitation. Mitral leaflet configuration was represented in contour to appreciate the degree of tenting in the vertical view from left ventricle (left). Horizontal view provides the degree of annulus nonplanarity and actual tenting of the leaflet (right). Black dots indicate coaptation line. Circumferences, area, and height of the mitral annulus were measured from these 3D data. (C) Corrected 3D tenting image. The curved mitral annulus was stretched on a flat plane, keeping the distance from the annular surface to the leaflet. Mitral leaflet tenting from the level of 3D mitral annulus was represented in contour in the vertical view from the left ventricle (LV) (left). Horizontal view provides the degree of tenting of the leaflet from the level of mitral annulus (right). Black dots indicate coaptation line. Maximum tenting length, mean tenting length and tenting volume were measured from these 3D data. A = anterior; P = posterior; CL = antero-lateral commissure; CM = postero-medial commissure; LA = left atrium.
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Figure 3 Three-dimensional (3D) images of mitral annulus and leaflets in ischemic mitral regurgitation. (A) Anatomical 3D image (views from two directions). Mitral annulus flattened with apparent tenting of the mitral leaflets, which were tethered into the left ventricle (LV), showing mountain-shape leaflet bulging. (B) Actual 3D tenting image. Mitral leaflets are apparently tethered and annular height is shorter compared with normal. Mitral annulus is dilated. Black dots indicate coaptation line. (C) Corrected 3D tenting image. Mitral leaflets are tethered almost symmetrically from the level of mitral annulus (left). Maximum tenting length is longer than control (right). Black dots indicate coaptation line. The green mark indicates the maximum tenting site of the leaflet. In this particular patient, the maximum tenting site is located at middle of the anterior leaflet. Abbreviations as in Figure 3.
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Figure 4 Mapping of the maximum tenting site in 12 patients with ischemic mitral regurgitation on a schematic leaflet. AL, AC, and AM indicate lateral, central, and medial side of the anterior leaflet; PL, PC, and PM indicate lateral, central, and medial side of the posterior leaflet, respectively. The site of the maximum tenting was located in the region of anterior leaflet in all 12 patients (4 in lateral side, 5 in central side and 3 in medial side).
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