title: Real-time 3-dimensional dynamics of functional mitral regurgitation: a prospective quantitative and mechanistic study.
abstract: BACKGROUND
  Three-dimensional transthoracic echocardiography (3D-TTE) with dedicated software permits quantification of mitral annulus dynamics and papillary muscle motion throughout the cardiac cycle.
  
  
  RESULTS
  Mitral apparatus 3D-TTE was acquired in controls (n=42), patients with left ventricle dysfunction and functional mitral regurgitation (LVD-FMR; n=43) or without FMR (LVD-noMR, n=35). Annulus in both normal and LVD-noMR subjects displayed saddle shape accentuation in early-systole (ratio of height to intercommissural diameter, 10.6 ± 3.7 to 13.5 ± 4.0 in normal and 9.1 ± 4.3 to 12.6 ± 3.6 in LVD-noMR; P<0.001 for diastole to early-systole motion, P=NS between those groups). In contrast, saddle shape was unchanged from diastole in FMR patients (10.0 ± 6.4 to 8.0 ± 5.2; P=NS, P<0.05 compared to both other groups). Papillary tips moved symmetrically towards to the midanterior annulus in control and LVD-noMR subjects, maintaining constant ratio of the distances between both tips to midannulus (PtAR) throughout systole. In LVD-FMR patients midsystolic posterior papillary tip to anterior annulus distance was increased, resulting in higher PtAR (P=0.05 compared to both other groups). Mechanisms of early- and midsystolic FMR differed between different etiologies of LV dysfunction. In patients with anterior MI and global dysfunction annular function and dilatation were the dominant parameters, while papillary muscle motion was the predominant determinant of FMR in patients with inferior MI.
  
  
  CONCLUSIONS
  Inadequate early-systolic annular contraction and saddle-shape accentuation in patients with impaired LV contribute to early-mitral incompetency. Asymmetric papillary tip movement towards the midanterior annulus is a major determinant of mid- and late-systolic functional mitral regurgitation.
authors.affiliation: Division of Cardiovascular Diseases, Tel Aviv Medical Center, Rochester, MN 55905, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Topilsky
authors.forename: Ori
authors.initials: O
authors.lastname: Vaturi
authors.forename: Nozomi
authors.initials: N
authors.lastname: Watanabe
authors.forename: Valentina
authors.initials: V
authors.lastname: Bichara
authors.forename: Vuyisile T
authors.initials: VT
authors.lastname: Nkomo
authors.forename: Hector
authors.initials: H
authors.lastname: Michelena
authors.forename: Thierry
authors.initials: T
authors.lastname: Le Tourneau
authors.forename: Sunil V
authors.initials: SV
authors.lastname: Mankad
authors.forename: Soon
authors.initials: S
authors.lastname: Park
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Capps
authors.forename: Rakesh
authors.initials: R
authors.lastname: Suri
authors.forename: Sorin V
authors.initials: SV
authors.lastname: Pislaru
authors.forename: Joseph
authors.initials: J
authors.lastname: Maalouf
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yoshida
authors.forename: Maurice
authors.initials: M
authors.lastname: Enriquez-Sarano
mesh_terms: D000368:Aged; D019560:Echocardiography, Three-Dimensional; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology*; D010210:Papillary Muscles / Q000503:physiopathology; D011446:Prospective Studies
keywords: echocardiography; mitral regurgitation; mitral valve annulus