title: Mitral annulus size links ventricular dilatation to functional mitral regurgitation.
abstract: We compared the impact of annulus size and valve deformation (tethering) on mitral regurgitation in the animal dilated cardiomyopathy model, and assessed if acute left ventricular volume changes affect mitral annulus dimensions. We performed 3-dimensional echocardiography in 30 open-chest dogs with pacing-induced cardiomyopathy. Mitral annulus area was calculated from its two orthogonal diameters, whereas valve tethering was quantified by valve tenting area measurement. Mitral valve regurgitant volume showed the highest correlation with annulus area (r = 0.64, P < .001), left atrial volume (r = 0.40, P < .01), and left ventricular end-diastolic volume (r = 0.37, P < .01). Regurgitant volume showed poorer correlation with valve tethering in both septolateral and intercommissural planes (r = 0.35 and r = 0.31, P < .05 for both). Annulus dimensions correlated with acute changes of left ventricular end-diastolic volume (r = 0.68, P = .002). Mitral annulus dilation is the strongest predictor of functional mitral regurgitation in this animal dilated cardiomyopathy model.
authors.affiliation: Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
authors.forename: Zoran B
authors.initials: ZB
authors.lastname: Popović
authors.forename: Maureen
authors.initials: M
authors.lastname: Martin
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Fukamachi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Inoue
authors.forename: Jun
authors.initials: J
authors.lastname: Kwan
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Doi
authors.forename: Jian Xin
authors.initials: JX
authors.lastname: Qin
authors.forename: Takahiro
authors.initials: T
authors.lastname: Shiota
authors.forename: Mario J
authors.initials: MJ
authors.lastname: Garcia
authors.forename: Patrick M
authors.initials: PM
authors.lastname: McCarthy
authors.forename: James D
authors.initials: JD
authors.lastname: Thomas
mesh_terms: D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging* / Q000209:etiology; D004285:Dogs; D004452:Echocardiography / Q000379:methods; D008943:Mitral Valve / Q000000981:diagnostic imaging*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000209:etiology; D008946:Mitral Valve Stenosis / Q000000981:diagnostic imaging* / Q000209:etiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000209:etiology