title: Prevalence and predictors of left atrial thrombus in patients with atrial fibrillation: is transesophageal echocardiography necessary before cardioversion?
abstract: BACKGROUND
  Systemic embolization threatens patients with atrial fibrillation (AF). The risk is enhanced at the time of cardioversion. Transesophageal echocardiography (TEE) prior to cardioversion to screen for left atrial thrombus (LAT), a marker of high risk for embolization, is recommended for many patients with AF.
  
  
  OBJECTIVE
  To determine clinical and echocardiographic factors associated with LAT formation in AF.
  
  
  METHODS
  Data from 600 consecutive patients with AF undergoing TEE prior to cardioversion for the detection of LAT were analyzed. Clinical, laboratory, and echocardiographic parameters were abstracted from the clinical record.
  
  
  RESULTS
  TEE identified LAT in 70 (11.6%) and dense (LA) spontaneous echo contrast (SEC) in 156 (26%). Baseline characteristics and echocardiographic parameters of patients with or without LAT are compared. A prior myocardial infarction, 21 (29.4 %) vs. 31 (5.8), (p < 0.001); hypertension, 60 (85.7%) vs. 386 (72.8), (p 0.02); CHADS(2) ≥ 2, 56 (80%) vs. 308 (58.1%), (p < 0.001) prevalence was higher in patients with LAT. Patients with LAT had lower ejection fraction 38.2 ± 15.6 vs. 46.2 ± 14.5, (p < 0.001); higher LA diameter 4.98 ± 0.7 vs. 4.52 ± 0.7, (p <0.001); dense LA SEC 44 (62.8) vs. 112 (21.1), (p < 0.001); and low LA appendage emptying velocity 21.7 ± 12.9 vs. 37.5 ± 19.4, (p < 0.001). Multivariate analysis was done, and it revealed that low LA emptying velocity had the strongest independent association with LAT (HR 0.89 [CI 0.83-0.96], p value <0.001.
  
  
  CONCLUSIONS
  LAT is not an uncommon finding of AF patients prior to cardioversion. The current practice of TEE examination may be justified since neither clinical nor routine 2D echo examinations reliably identify LAT.
authors: Division of Cardiology, Washington Hospital Center, Washington, DC.
authors: Rahul
authors: R
authors: Malik
authors: Division of Cardiology, University of Michigan Health System, Ann Arbor, MI.
authors: Daniel M
authors: DM
authors: Alyeshmerni
authors: Division of Cardiology, Washington Hospital Center, Washington, DC.
authors: Zuyue
authors: Z
authors: Wang
authors: Division of Cardiology, Washington Hospital Center, Washington, DC.
authors: Steven A
authors: SA
authors: Goldstein
authors: Division of Cardiology, Washington Hospital Center, Washington, DC.
authors: Rebecca
authors: R
authors: Torguson
authors: Division of Cardiology, Washington Hospital Center, Washington, DC.
authors: Joseph
authors: J
authors: Lindsay
authors: Division of Cardiology, Washington Hospital Center, Washington, DC. Electronic address: ron.waksman@medstar.net.
authors: Ron
authors: R
authors: Waksman
authors: Division of Cardiology, Washington Hospital Center, Washington, DC.
authors: Itsik
authors: I
authors: Ben-Dor
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D017548:Echocardiography, Transesophageal; D004554:Electric Countershock; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D013927:Thrombosis / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000503:physiopathology
keywords: Atrial fibrillation; Left atrial thrombus; Thrombus