title: Quantitation of the mitral tetrahedron in patients with ischemic heart disease using real-time three-dimensional echocardiography to evaluate the geometric determinants of ischemic mitral regurgitation.
abstract: BACKGROUND
  Ischemic mitral regurgitation (IMR) is common in ischemic heart disease and results in poor prognosis. However, the exact mechanism of IMR has not been fully elucidated.
  
  
  OBJECTIVE
  Quantitation of the mitral tetrahedron using three-dimentianl (3D) echocardiography is capable of evaluating the geometric determinants and mechanisms of IMR.
  
  
  METHODS
  Forty patients with a history of ST-elevation myocardial infarction at least 6 months earlier were studied. Parameters of mitral deformation and global left ventricular (LV) function and shape were evaluated by 2-dimensional echocardiography. The effective regurgitant orifice (ERO) of IMR was obtained by the quantitative continuous-wave Doppler technique. Three-dimensional (3D) echocardiography was applied to assess the mitral tetrahedron.
  
  
  RESULTS
  Mitral valvular tenting area (P < 0.001), mitral annular area (P = 0.032), dilation of the LV in diastole, impairment of the LV ejection fraction, and volume of the spherically shaped LV in systole were greater in patients with an ERO ≥20 mm(2) than in those with an ERO <20 mm(2). In the mitral tetrahedron, only the interpapillary muscle roots distance showed a significant difference (P = 0.004). Multivariate analysis with the logistic regression model showed the systolic mitral tenting area (odds ratio [OR]: 280.49, 95% confidence interval [CI]: 4.59-1.72 × 10(4), P = 0.007) and interpapillary muscle distance (OR: 1.50, 95% CI: 1.03-2.19, P = 0.036) to be independent factors in predicting significant IMR (ERO ≥20 mm(2)).
  
  
  CONCLUSIONS
  3D echocardiography can be effectively applied in measuring the mitral tetrahedron and evaluating the mechanism of IMR. Mitral valvular tenting and interpapillary muscle distance are 2 independent factors of significant IMR.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, E-Da Hospital, I-Shou University, Kaohsiung, Taiwan.
authors.forename: Chin-Feng
authors.initials: CF
authors.lastname: Hsuan
authors.forename: Hsi-Yu
authors.initials: HY
authors.lastname: Yu
authors.forename: Wei-Kung
authors.initials: WK
authors.lastname: Tseng
authors.forename: Lung-Chun
authors.initials: LC
authors.lastname: Lin
authors.forename: Kwan-Lih
authors.initials: KL
authors.lastname: Hsu
authors.forename: Chau-Chung
authors.initials: CC
authors.lastname: Wu
mesh_terms: D000368:Aged; D015150:Echocardiography, Doppler; D019560:Echocardiography, Three-Dimensional; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015588:Observer Variation; D016017:Odds Ratio; D010210:Papillary Muscles / Q000000981:diagnostic imaging / Q000503:physiopathology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012307:Risk Factors; D012720:Severity of Illness Index; D013599:Systole; D016277:Ventricular Function, Left