title: Comparison of echocardiography and electron beam tomography in differentiating the etiology of heart failure.
abstract: BACKGROUND
  The clinical manifestations in patients with ischemic cardiomyopathy are often indistinguishable from those in patients with primary dilated cardiomyopathy (DCM). Clinicians often base work-up of patients with heart failure on echocardiographic wall motion abnormalities; however misclassification can lead to unnecessary coronary angiography.
  
  
  OBJECTIVE
  The study was undertaken to evaluate the diagnostic ability of echocardiography and electron beam tomography (EBT) to differentiate between ischemic and nonischemic cardiomyopathy.
  
  
  METHODS
  The accuracy of EBT and echocardiography was compared in 111 patients undergoing coronary angiography for the evaluation of heart failure. The presence of coronary calcification (CC) by EBT or segmental wall motion abnormalities by echocardiography was used as evidence of coronary-induced cardiomyopathy.
  
  
  RESULTS
  Of 63 patients, 61 (97%) with obstructive coronary artery disease had CC by EBT. This sensitivity was significantly higher compared with 43 of 63 patients (68%) with segmental wall motion abnormalities by echocardiography (p < 0.001). Of 48 patients without obstructive coronary artery disease by angiography, 39 (81%) had no CC by EBT and 35 (73%) had no segmental wall motion (global hypokinesis) by echocardiography (p = 0.33). The overall accuracy of EBT to differentiate ischemic from nonischemic cardiomyopathy was 90%, significantly higher than echocardiography (70%, p < 0.001).
  
  
  CONCLUSIONS
  This double-blind study demonstrates that the presence of CC by EBT is superior to that of segmental wall motion abnormalities by echocardiography to distinguish ischemic from nonischemic cardiomyopathy. This modality may prove to be an important diagnostic tool when the etiology of the cardiomyopathy is not clinically evident.
authors.affiliation: Department of Medicine, Harbor-UCLA Research and Education Institute, Torrance, USA.
authors.forename: T
authors.initials: T
authors.lastname: Le
authors.forename: J Y
authors.initials: JY
authors.lastname: Ko
authors.forename: H T
authors.initials: HT
authors.lastname: Kim
authors.forename: P
authors.initials: P
authors.lastname: Akinwale
authors.forename: M J
authors.initials: MJ
authors.lastname: Budoff
mesh_terms: D000328:Adult; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis* / Q000000981:diagnostic imaging; D017023:Coronary Angiography; D004311:Double-Blind Method; D006801:Humans; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography