title: Alterations of regional myocardial function in a swine model of myocardial infarction assessed by echocardiographic 2-dimensional strain imaging.
abstract: BACKGROUND
  Tissue Doppler strain and strain rate imaging have been introduced for quantitative assessment of regional myocardial function. These techniques are largely limited to the evaluation of overall longitudinal myocardial function. This study attempted to apply radial strain, circumferential strain, radial displacement, and strain-based torsion analysis to differentiating the infarct, adjacent, and remote zones in a swine model of myocardial infarction.
  
  
  METHODS
  Seven pigs, body weight 24 to 26 kg, were subjected to myocardial infarction by occlusion of the left anterior descending coronary artery (LAD) and followed up for 8 weeks. Regional radial and circumferential deformations were quantified noninvasively by ultrasonic strain rate imaging before LAD occlusion, LAD occlusion immediately, and 4, 6, and 8 weeks after LAD occlusion. Strain-based left ventricular torsion was assessed at the same time points.
  
  
  RESULTS
  Both radial and circumferential strains, and torsion, were decreased significantly in the LAD territory areas as a result of myocardial ischemia and infarction. There were no significant changes in radial and circumferential strains, or torsion, in the areas of adjacent and remote zones over time.
  
  
  CONCLUSIONS
  These findings demonstrate that speckle-tracking strain imaging may be suitable for noninvasive quantification of left ventricular segmental function of ischemic heart disease.
authors.affiliation: The Cleveland Clinic Foundation, Cleveland, Ohio, USA. jingpingsun6@yahoo.com <jingpingsun6@yahoo.com>
authors.forename: Jing Ping
authors.initials: JP
authors.lastname: Sun
authors.forename: Jianli
authors.initials: J
authors.lastname: Niu
authors.forename: David
authors.initials: D
authors.lastname: Chou
authors.forename: Hsuan-Hung
authors.initials: HH
authors.lastname: Chuang
authors.forename: Kai
authors.initials: K
authors.lastname: Wang
authors.forename: Jeanne
authors.initials: J
authors.lastname: Drinko
authors.forename: Allen
authors.initials: A
authors.lastname: Borowski
authors.forename: William J
authors.initials: WJ
authors.lastname: Stewart
authors.forename: James D
authors.initials: JD
authors.lastname: Thomas
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004452:Echocardiography / Q000379:methods*; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009200:Myocardial Contraction / Q000502:physiology*; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012720:Severity of Illness Index; D013552:Swine; D014102:Torsion Abnormality; D016277:Ventricular Function, Left / Q000502:physiology*