title: Novel parameters of global and regional mitral annulus geometry in man: comparison between normals and organic mitral regurgitation, before and after mitral valve repair.
abstract: OBJECTIVE
  The mitral annulus (MA) saddle shape is complex but vital for a normal functioning mitral apparatus. Although conventional parameters of MA geometry such as area and height are helpful, they fall short of describing its complex regional geometry.
  
  
  RESULTS
  In this prospective study, novel parameters of MA curvature and torsion were derived from three-dimensional (3D) transoesophageal echocardiography. These quantitative indices were computed in 15 patients with normal valves (age 53 ± 8 years) and in 15 patients with organic significant mitral regurgitation (MR, age 66 ± 11 years), before and after mitral valve repair (MVR). The MA was traced and modelled in mid- and end-systole. Curvature and torsion were computed at 500 points across the MA to derive regional and global indices. Overall, patients with organic MR presented the smallest global curvature and torsion; this decrease in curvature and torsion reflects a loss of tonicity of the MA tissue. These changes were largely corrected with MVR surgery, to higher values, compared with normals. The regional analysis revealed similar trends. The maximal MA curvature was found to be at the MA 'anterior horn', whereas the MA 'posterior horn' had the lowest curvature values.
  
  
  CONCLUSIONS
  Novel MA parameters of curvature and torsion can be computed from 3D echocardiography and provide quantitative characteristics of dynamic regional MA geometry. In patients with organic MR, the reduced regional and global curvatures improve following surgical MVR. These quantitative parameters may help further refine the quantitative description of MA geometry in various mitral valve pathologies and after MVR.
authors.affiliation: Echocardiography Department, Cardiovascular Imaging Institute, The Methodist DeBakey Heart and Vascular Center, 6550 Fannin Street, SM 677, Houston, TX 77030, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ben Zekry
authors.affiliation: Department of Mathematics, University of Houston, Houston, TX, USA.
authors.forename: S
authors.initials: S
authors.lastname: Jain
authors.affiliation: Department of Mathematics, University of Houston, Houston, TX, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Alexander
authors.affiliation: Department of Mathematics, University of Houston, Houston, TX, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Mathematics, University of Houston, Houston, TX, USA.
authors.forename: A
authors.initials: A
authors.lastname: Aggarwal
authors.affiliation: Department of Mathematics, University of Houston, Houston, TX, USA.
authors.forename: A
authors.initials: A
authors.lastname: Jajoo
authors.affiliation: Echocardiography Department, Cardiovascular Imaging Institute, The Methodist DeBakey Heart and Vascular Center, 6550 Fannin Street, SM 677, Houston, TX 77030, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Little
authors.affiliation: Cardiovascular and Thoracic Surgery, The Methodist DeBakey Heart and Vascular Center, Houston, TX, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Lawrie
authors.affiliation: Department of Mathematics, University of Houston, Houston, TX, USA.
authors.forename: R
authors.initials: R
authors.lastname: Azencott
authors.affiliation: Echocardiography Department, Cardiovascular Imaging Institute, The Methodist DeBakey Heart and Vascular Center, 6550 Fannin Street, SM 677, Houston, TX 77030, USA wzoghbi@houstonmethodist.org.
authors.forename: W A
authors.initials: WA
authors.lastname: Zoghbi
mesh_terms: D000368:Aged; D019560:Echocardiography, Three-Dimensional; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D011446:Prospective Studies
keywords: Mitral annulus; Mitral valve repair; Organic mitral regurgitation