title: Borderzone geometry after acute myocardial infarction: a three-dimensional contrast enhanced echocardiographic study.
abstract: BACKGROUND
  Regional myocardial geometry, function, and perfusion status are critical variables for understanding infarction-induced left ventricle (LV) remodeling. Three-dimensional contrast echocardiography (3DCE) is uniquely suited to measure these parameters. We evaluate the ability of 3DCE to assess geometric changes in the normally perfused but hypocontractile borderzone myocardium (BZM) immediately after a myocardial infarction (MI) in an ovine model, and we compare 3DCE with two-dimensional contrast echocardiography (2DCE) in the long and short axis.
  
  
  METHODS
  Four sheep were studied with 3DCE and 4 were studied using 2DCE, before and 30 minutes after an anteroapical MI. Each 3DCE data set was acquired over 18 consecutive cardiac cycles. The LV geometry was reconstructed and perfusion data spatially correlated, thereby constituting a 3D model of ventricular geometry and perfusion. The borderzone was defined as the contrast-perfused myocardium adjacent to the infarct.
  
  
  RESULTS
  The 2DCE short-axis analysis demonstrated decreased curvature and decreased wall thickness in the borderzone after MI. These findings are consistent with increased BZM wall stress. However, the long-axis 2DCE analysis demonstrated increased BZM wall thickness and a surprising change in BZM concavity acutely after infarction. The 3DCE analysis confirmed these findings and added additional information regarding regional variability in BZM geometry that was not evident in the two orthogonal 2D views.
  
  
  CONCLUSIONS
  This study provides evidence that regional changes in BZM geometry are more complex than previously believed and are not necessarily indicative of increased regional stress. The superiority of 3DCE over 2DCE for assessing these changes is strongly supported.
authors.affiliation: Division of Cardiology, Harrison Department of Surgical Research, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-4283, USA.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Jackson
authors.forename: Landi M
authors.initials: LM
authors.lastname: Parish
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Gorman
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Enomoto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Theodore
authors.initials: T
authors.lastname: Plappert
authors.forename: Martin G
authors.initials: MG
authors.lastname: St John Sutton
authors.forename: Ivan
authors.initials: I
authors.lastname: Salgo
authors.forename: Robert C
authors.initials: RC
authors.lastname: Gorman
mesh_terms: D000818:Animals; D003287:Contrast Media; D019560:Echocardiography, Three-Dimensional / Q000379:methods; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology*; D012756:Sheep; D020257:Ventricular Remodeling
chemical_list: D003287:Contrast Media