title: Three-dimensional echocardiographic assessment of annular shape changes in the normal and regurgitant mitral valve.
abstract: OBJECTIVE
  To compare mitral annular shape and motion throughout the cardiac cycle in patients with normal hearts versus those with functional mitral regurgitation (FMR).
  
  
  BACKGROUND
  The causes of mitral regurgitation without valvular disease are unclear, but the condition is associated with changes in annular shape and dynamics. Three-dimensional (3D) imaging provides a more comprehensive view of annular structure and allows accurate reconstructions at high spatial and temporal resolution.
  
  
  METHODS
  Nine normal subjects and 8 patients with FMR undergoing surgery underwent rotationally scanned transesophageal echocardiography. At every video frame of 1 sinus beat, the mitral annulus was manually traced and reconstructed in 3D by Fourier series. Annular projected area, nonplanarity, eccentricity, perimeter length, and interpeak and intervalley spans were determined at 10 time points in systole and 10 points in diastole.
  
  
  RESULTS
  The mitral annulus in patients with FMR had a larger area, perimeter, and interpeak span than in normal subjects (P <.001 for all). At mid-systole in normal annuli, area and perimeter reach a minimum, nonplanarity is greatest, and projected shape is least circular. These cyclic variations were not significant in patients with FMR. Annular area change closely paralleled perimeter change in all patients (mean r = 0.96 +/- 0.07).
  
  
  CONCLUSIONS
  FMR is associated with annular dilation and reduced cyclic variation in annular shape and area. Normal mitral valve function may depend on normal annular 3D shape and dimensions as well as annular plasticity. These observations may have implications for design and selection of mitral annular prostheses.
authors.affiliation: Division of Cardiology, Department of Medicine, University of Washington, Seattle, WA 98195-6422, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Kaplan
authors.forename: G
authors.initials: G
authors.lastname: Bashein
authors.forename: F H
authors.initials: FH
authors.lastname: Sheehan
authors.forename: M E
authors.initials: ME
authors.lastname: Legget
authors.forename: B
authors.initials: B
authors.lastname: Munt
authors.forename: X N
authors.initials: XN
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Sivarajan
authors.forename: E L
authors.initials: EL
authors.lastname: Bolson
authors.forename: M
authors.initials: M
authors.lastname: Zeppa
authors.forename: M Z
authors.initials: MZ
authors.lastname: Arch
authors.forename: R W
authors.initials: RW
authors.lastname: Martin
mesh_terms: D000328:Adult; D000368:Aged; D003971:Diastole / Q000502:physiology; D019560:Echocardiography, Three-Dimensional; D017548:Echocardiography, Transesophageal; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging* / Q000502:physiology; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000601:surgery; D015588:Observer Variation; D012044:Regression Analysis; D012720:Severity of Illness Index; D013599:Systole / Q000502:physiology