title: Mitral Annular Dynamics in Mitral Annular Calcification: A Three-Dimensional Imaging Study.
abstract: BACKGROUND
  The mitral annulus displays complex conformational changes during the cardiac cycle that can now be quantified by three-dimensional echocardiography. Mitral annular calcification (MAC) is increasingly encountered, but its structural and dynamic consequences are largely unexplored. The objective of this study was to describe alterations in mitral annular dimensions and dynamics in patients with MAC.
  
  
  METHODS
  Transthoracic three-dimensional echocardiography was performed in 43 subjects with MAC and 36 age- and sex-matched normal control subjects. Mitral annular dimensions were quantified, using dedicated software, at six time points (three diastolic, three systolic) during the cardiac cycle.
  
  
  RESULTS
  In diastole, the calcified annulus was larger and flatter than normal, with increased anteroposterior diameter (29.4 ± 0.6 vs 27.8 ± 0.6 mm, P = .046), reduced height (2.8 ± 0.2 vs 3.6 ± 0.2 mm, P = .006), and decreased saddle shape (8.9 ± 0.6% vs 11.4 ± 0.6%, P = .005). In systole, patients with MAC had greater annular area at all time points (P < .05 for each) compared with control subjects, because of reduced contraction along the anteroposterior diameter (P < .001). Saddle shape increased in early systole (from 10.5% to 13.5%, P = .04) in control subjects but not in those with MAC (P = NS). Valvular alterations were also noted; although mitral valve tent length decreased during systole in both groups, decreases were less in patients with MAC (P < .05 for mid- and late systole). For certain parameters (e.g., annular area), changes were confined largely to those patients with moderate to severe MAC (P = .006 vs control subjects, but nonsignificant for patients with mild MAC).
  
  
  CONCLUSIONS
  Quantitative three-dimensional echocardiography provides new insights into the dynamic consequences of MAC. This imaging technique demonstrates that the mitral annulus is not made smaller by calcification. However, there is loss of annular contraction, particularly along the anteroposterior diameter, and loss of early systolic folding along the intercommissural diameter. Associated valvular alterations include smaller than usual declines in tenting during systole. These quantitative three-dimensional echocardiographic data provide new insights into the dynamic physiology of the calcified mitral annulus.
authors.affiliation: Division of Cardiovascular Diseases, Einstein Medical Center, Philadelphia, Pennsylvania. Electronic address: pressmang@einstein.edu.
authors.forename: Gregg S
authors.initials: GS
authors.lastname: Pressman
authors.affiliation: Division of Cardiovascular Diseases, Einstein Medical Center, Philadelphia, Pennsylvania.
authors.forename: Rajesh
authors.initials: R
authors.lastname: Movva
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Yan
authors.initials: Y
authors.lastname: Topilsky
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Marie-Annick
authors.initials: MA
authors.lastname: Clavel
authors.affiliation: Dalhousie University, Halifax, Nova Scotia, Canada.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Saldanha
authors.affiliation: Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Maurice
authors.initials: M
authors.lastname: Enriquez-Sarano
mesh_terms: D002114:Calcinosis / Q000000981:diagnostic imaging*; D009202:Cardiomyopathies / Q000000981:diagnostic imaging*; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012720:Severity of Illness Index
keywords: Mitral annular calcification; Mitral annular dynamics; Three-dimensional echocardiography