title: Moderate mitral regurgitation accelerates left ventricular remodeling after posterolateral myocardial infarction.
abstract: BACKGROUND
  Chronic ischemic mitral regurgitation (MR) is associated with poor outcome. However, the effect of chronic ischemic MR on left ventricular (LV) remodeling after posterolateral myocardial infarction (MI) remains controversial. We tested the hypothesis that moderate MR accelerates LV remodeling after posterolateral MI.
  
  
  METHODS
  Posterolateral MI was created in 10 sheep. Cardiac magnetic resonance imaging was performed 2 weeks before and 2, 8, and 16 weeks after MI. Left ventricular and right ventricular volumes were measured, and regurgitant volume was calculated as the difference between LV and right ventricle stroke volumes.
  
  
  RESULTS
  Multivariate mixed effects regression showed that LV volumes at end diastole and end systole and LV sphericity were strongly correlated with both regurgitant volume (p < 0.0001, p = 0.0086, and p = 0.0007, respectively) and percent infarct area (p = 0.0156, p = 0.0307, and p < 0.0001, respectively). Conversely, whereas LV hypertrophy (LV wall volume) increased from 2 weeks to 16 weeks after MI, there was no effect of either regurgitant volume or percent infarct.
  
  
  CONCLUSIONS
  Moderate MR accelerates LV remodeling after posterolateral MI. Further studies are needed to determine whether mitral valve repair is able to slow or reverse MI remodeling after posterolateral MI.
authors.affiliation: Veterans Affairs Medical Center, San Francisco, California 94121, USA.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Soleimani
authors.forename: Michael
authors.initials: M
authors.lastname: Khazalpour
authors.forename: Guangming
authors.initials: G
authors.lastname: Cheng
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Zhang
authors.forename: Gabriel
authors.initials: G
authors.lastname: Acevedo-Bolton
authors.forename: David A
authors.initials: DA
authors.lastname: Saloner
authors.forename: Rakesh
authors.initials: R
authors.lastname: Mishra
authors.forename: Arthur W
authors.initials: AW
authors.lastname: Wallace
authors.forename: Julius M
authors.initials: JM
authors.lastname: Guccione
authors.forename: Liang
authors.initials: L
authors.lastname: Ge
authors.forename: Mark B
authors.initials: MB
authors.lastname: Ratcliffe
mesh_terms: D000818:Animals; D008944:Mitral Valve Insufficiency / Q000150:complications*; D009203:Myocardial Infarction / Q000150:complications*; D012720:Severity of Illness Index; D012756:Sheep; D020257:Ventricular Remodeling