title: Left atrial spontaneous echo contrast is highly associated with previous stroke in patients with atrial fibrillation or mitral stenosis.
abstract: OBJECTIVE
  Spontaneous echo contrast is a dynamic smokelike signal that is detected by transesophageal echocardiography in patients with stasis of blood in the left atrium. We designed this study to determine if spontaneous echo contrast is associated with an increased risk of previous stroke or peripheral embolism.
  
  
  METHODS
  Forty-two patients with spontaneous echo contrast were identified (34 had atrial fibrillation or mitral stenosis; 8 had neither). Control subjects comprised 40 patients randomly selected from patients with atrial fibrillation or mitral stenosis who did not have spontaneous echo contrast at transesophageal echocardiography. The frequency of vascular risk factors, echocardiographic features, and stroke or peripheral embolism within 1 year of echocardiography were compared in the two groups.
  
  
  RESULTS
  The frequency of traditional risk factors for stroke were the same in both groups, yet 9 of 42 patients with spontaneous contrast had stroke or peripheral embolism compared with only 1 of 40 control subjects (P < .02; relative risk, 10.6; 95% confidence interval, 1.3 to 88.4). In patients with nonvalvular atrial fibrillation, 6 of 12 patients with spontaneous contrast had a stroke or peripheral embolism compared with 1 of 28 patients without spontaneous contrast (P < .001; relative risk, 27.0; 95% confidence interval, 2.7 to 267.8).
  
  
  CONCLUSIONS
  Spontaneous echo contrast is highly associated with previous stroke or peripheral embolism in patients with atrial fibrillation or mitral stenosis. Transesophageal echocardiography may enable stratification of cardioembolic risk in patients with nonvalvular atrial fibrillation.
authors.affiliation: Department of Neurology, University of Michigan Medical Center, Ann Arbor 48109.
authors.forename: M I
authors.initials: MI
authors.lastname: Chimowitz
authors.forename: M A
authors.initials: MA
authors.lastname: DeGeorgia
authors.forename: R M
authors.initials: RM
authors.lastname: Poole
authors.forename: A
authors.initials: A
authors.lastname: Hepner
authors.forename: W M
authors.initials: WM
authors.lastname: Armstrong
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000150:complications*; D002561:Cerebrovascular Disorders / Q000150:complications* / Q000000981:diagnostic imaging; D004452:Echocardiography; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008946:Mitral Valve Stenosis / Q000150:complications*; D011859:Radiography; D012307:Risk Factors