Quantitative measurement of mitral valve coaptation in functional mitral regurgitation: In vivo experimental study by real-time three-dimensional echocardiography.
BACKGROUND
The degree of mitral valve (MV) coaptation should be an important parameter in the assessment of functional mitral regurgitation (MR). This study aimed to quantify the degree of MV coaptation in experimental models of functional MR caused by acute left ventricular (LV) pressure overload, using real-time three-dimensional (3D) echocardiography.


RESULTS
Using canine models, LV pressure overload was induced by staged ascending aortic banding. Echocardiographic examinations were performed before and during the aortic banding. By using a novel software system for 3D quantification (REALVIEW®), the annulus and leaflet were traced manually both at the onset of MV closure and at the maximum MV closure. The coaptation index was calculated by the following formula: [(3D tenting surface area at the onset of MV closure-3D tenting surface area at the maximum MV closure)/3D tenting surface area at the onset of MV closure] x 100. MR area gradually increased with the decrease in coaptation index during progressively exacerbated aortic banding. MR area was significantly correlated with the coaptation index. A coaptation index < 12 had a high sensitivity and specificity in the presence of significant MR.


CONCLUSIONS
The degree of MV coaptation can be quantified using 3D echocardiography. The coaptation index should be a useful parameter in the assessment of functional MR.
Yamada
Ryotaro
R
Department of Cardiology, Kawasaki Medical School, Kurashiki, Japan. ryotaro@med.kawasaki-m.ac.jp
Watanabe
Nozomi
N
Kume
Teruyoshi
T
Tsukiji
Miwako
M
Kawamoto
Takahiro
T
Neishi
Yoji
Y
Hayashida
Akihiro
A
Toyota
Eiji
E
Okura
Hiroyuki
H
Yoshida
Kiyoshi
K
D000818:Animals; D003199:Computer Systems; D004285:Dogs; D019560:Echocardiography, Three-Dimensional; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006439:Hemodynamics; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology