title: The relationship between left ventricular ejection fraction and infarct size assessed by MRI.
abstract: OBJECTIVE
  We sought to study the relationship between left ventricular ejection fraction (LVEF) and infarct size in patients with ischemic heart disease (IHD) using magnetic resonance imaging (MRI), and to determine a dysfunction index based on the maximum possible LVEF in relation to infarct size.
  
  
  METHODS
  In 149 patients with chronic IHD, LVEF and infarct size were quantified by MRI. Dysfunction index was defined as the maximum possible LVEF minus measured LVEF.
  
  
  RESULTS
  The maximum possible LVEF was found to be LVEF=72.2-[1.18*infarct size]. Dysfunction index for the study population was mean 20 (range -6 to 57), 74% of the study population had a dysfunction index >10 and 44% had a dysfunction index >20.
  
  
  CONCLUSIONS
  The present study suggests that infarct size by MRI can be used to estimate a maximum possible LVEF and a dysfunction index. The distribution of dysfunction index in the population suggests a considerable prevalence of dysfunctional but viable myocardium. Future studies are needed to assess if the dysfunction index can be useful to assess the potential for improvement in LVEF following revascularization.
authors: Cardiac MR Group, Department of Clinical Physiology, Lund University Hospital, Lund, Sweden.
authors: Martin
authors: M
authors: Ugander
authors: Björn
authors: B
authors: Ekmehag
authors: Håkan
authors: H
authors: Arheden
mesh_terms: D000368:Aged; D005260:Female; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000473:pathology*; D012189:Retrospective Studies; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000209:etiology / Q000473:pathology*; D016277:Ventricular Function, Left