title: Effects of severity of the residual stenosis of the infarct-related coronary artery on left ventricular dilation and function after acute myocardial infarction.
abstract: OBJECTIVE
  This study was designed to evaluate the relation between the severity of the residual stenosis of the infarct-related artery and changes in left ventricular volume and function after a first anterior myocardial infarction.
  
  
  BACKGROUND
  Although thrombolytic therapy improves clinical outcome after acute myocardial infarction, the relations between the severity of the residual stenosis of the infarct-related artery and postinfarction left ventricular remodeling and function are unclear.
  
  
  METHODS
  Fifty-eight patients with a first anterior myocardial infarction and significant disease only in the left anterior descending coronary artery on arteriography performed after 7 to 10 days were evaluated. All patients received thrombolytic therapy. Residual stenosis of the infarct-related artery was measured with quantitative coronary arteriography. Left ventricular volumes and ejection fraction were measured by echocardiography and radionuclide angiography, respectively, 7 to 10 days, 6 months and 1 year after infarction. End-diastolic and end-systolic left ventricular volumes were measured by two-dimensional echocardiography and normalized to body surface area. Patients were classified into three groups according to baseline residual stenosis severity: total occlusion (Group I), minimal lesion diameter less than 1.5 mm (Group II) and minimal diameter greater than or equal to 1.5 mm (Group III).
  
  
  RESULTS
  Group I patients had significantly greater left ventricular end-diastolic and end-systolic volumes at 6 months and 1 year than did the other groups. Group II patients had greater end-diastolic and end-systolic volumes than did Group III patients at 1 year. In addition, Group I patients had a lower ejection fraction at 1 year than that of the other groups. The minimal lesion diameter was significantly correlated with percent change in end-diastolic volume at 1 year.
  
  
  CONCLUSIONS
  The severity of the baseline residual stenosis of the infarct-related artery is an important predictor of change in left ventricular volumes in the 1st year after infarction. Total occlusion of the infarct-related artery is associated with greater left ventricular dilation and functional impairment.
authors.affiliation: Cardiology Division, Stanford University School of Medicine, California.
authors.forename: W H
authors.initials: WH
authors.lastname: Leung
authors.forename: C P
authors.initials: CP
authors.lastname: Lau
mesh_terms: D006328:Cardiac Catheterization; D017023:Coronary Angiography; D003327:Coronary Disease / Q000175:diagnosis / Q000503:physiopathology*; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy / Q000503:physiopathology*; D011875:Radionuclide Angiography; D013318:Stroke Volume / Q000502:physiology; D015912:Thrombolytic Therapy; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use; D016277:Ventricular Function, Left / Q000502:physiology*
chemical_list: D010959:Tissue Plasminogen Activator