title: Asymmetric versus symmetric tethering patterns in ischemic mitral regurgitation: geometric differences from three-dimensional transesophageal echocardiography.
abstract: BACKGROUND
  Ischemic mitral regurgitation (IMR) results from mitral leaflet tethering from left ventricular remodeling. Heterogeneity in local or global left ventricular remodeling can result in differential tethering patterns and affect mitral valve function and the degree of mitral regurgitation. The aims of this study were to compare mitral valve geometry in asymmetric and symmetric tethering patterns using three-dimensional transesophageal echocardiography and to examine the impact of tethering pattern on IMR severity.
  
  
  METHODS
  Sixty-two patients with moderate or greater IMR underwent three-dimensional transesophageal echocardiography for the assessment of mitral valve geometry. Symmetric and asymmetric tethering patterns were determined by mitral regurgitation jet direction and coaptation of the mitral leaflets. The ratio of posterior to anterior leaflet tethering angle was a measure of tethering pattern (the higher the ratio, the more asymmetric the pattern). Overall tethering degree was assessed by tenting volume (TV).
  
  
  RESULTS
  Compared with the symmetric group, the asymmetric group had less annular dilatation, greater annular heights (10.3 ± 1.9 vs 8.5 ± 1.9 mm, P < .01), greater ratios of posterior to anterior leaflet tethering angle (3.19 ± 0.88 vs 1.95 ± 0.46, P < .01), and smaller TVs with more posterior displacement of the coaptation line. Vena contracta normalized to TV was greater in the asymmetric group (0.38 ± 0.24 vs 0.19 ± 0.13 cm/mL, P < .01). Multivariate analysis showed that both ratio of posterior to anterior leaflet tethering angle (β = 0.46, P < .001) and TV (β = 0.41, P = .001) were predictors of IMR severity.
  
  
  CONCLUSIONS
  Differences in mitral valve geometry are observed between asymmetric and symmetric tethering patterns in IMR. IMR degree is affected by both the pattern of tethering and the total degree of tethering. For the same degree of tethering, an asymmetric pattern is associated with increased MR severity. The pattern of mitral leaflet tethering may be considered in therapeutic decision making.
authors: Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, Massachusetts.
authors: Xin
authors: X
authors: Zeng
authors: Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, Massachusetts.
authors: Maria Carmo P
authors: MC
authors: Nunes
authors: Cardiovascular Division, University of Virginia, Charlottesville, Virginia.
authors: John
authors: J
authors: Dent
authors: Cardiovascular Medicine, Atlantic Health System, Morristown, New Jersey.
authors: Linda
authors: L
authors: Gillam
authors: Division of Cardiothoracic Anesthesiology, Duke University Medical Center, Durham, North Carolina.
authors: Joseph P
authors: JP
authors: Mathew
authors: Division of Cardiac Surgery, University of Maryland School of Medicine, Baltimore, Maryland.
authors: James S
authors: JS
authors: Gammie
authors: Department of Health Evidence and Policy, Mount Sinai School of Medicine, New York, New York; Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York.
authors: Deborah D
authors: DD
authors: Ascheim
authors: Department of Health Evidence and Policy, Mount Sinai School of Medicine, New York, New York.
authors: Ellen
authors: E
authors: Moquete
authors: Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, Massachusetts. Electronic address: jhung@partners.org.
authors: Judy
authors: J
authors: Hung
mesh_terms: D000368:Aged; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging*; D008944:Mitral Valve Insufficiency / Q000150:complications / Q000000981:diagnostic imaging*; D017202:Myocardial Ischemia / Q000150:complications / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Ischemic mitral regurgitation; Mitral valve; Three-dimensional; Transesophageal echocardiography