title: Impact of increased infarct transmurality on remodeling and function during healing after anterior myocardial infarction in the dog.
abstract: To determine the impact of greater infarct transmurality on changes in left ventricular remodeling and function after acute anterior myocardial infarction, serial topographic and functional parameters (two-dimensional echocardiograms) and hemodynamics over 6 weeks, and postmortem topography (planimetry) at 6 weeks, were measured in chronically instrumented dogs randomized to standard coronary artery ligation (group 1) or a modified lower ligation plus collateral obliteration to decrease collateral inflow and increase transmurality (group 2). At 6 weeks, postmortem scar size and collagen were similar in the two groups, but group 2 had greater transmurality associated with more necrosis relative to area at risk, Q waves, infarct expansion, thinning, regional bulging, and cavity dilatation. Over the 6 weeks, group 2 showed more early expansion, late thinning and regional bulging in the short axis, larger diastolic and systolic volumes, and more apical aneurysmal bulging in the long-axis, reflecting more topographic deterioration. More important, group 2 showed greater regional and global left ventricular dysfunction over 6 weeks, lower ejection fraction at 2 days with further decrease over 6 weeks, and more left ventricular thrombus, ventricular arrhythmias, and deaths. In addition, transmurality correlated with the severity of remodeling and dysfunction. The findings indicate that transmurality is a major determinant of remodeling and left ventricular dysfunction during healing after anterior infarction.
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, Canada.
authors.forename: B I
authors.initials: BI
authors.lastname: Jugdutt
authors.forename: M I
authors.initials: MI
authors.lastname: Khan
mesh_terms: D000818:Animals; D003094:Collagen / Q000378:metabolism; D003326:Coronary Circulation / Q000502:physiology; D003331:Coronary Vessels / Q000378:metabolism / Q000473:pathology; D004285:Dogs; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006909:Hydroxyproline / Q000378:metabolism; D008297:Male; D008863:Microspheres; D009203:Myocardial Infarction / Q000473:pathology*; D009206:Myocardium / Q000473:pathology; D016277:Ventricular Function, Left / Q000502:physiology
chemical_list: D003094:Collagen; D006909:Hydroxyproline