title: Prospective evaluation of two-dimensional transthoracic echocardiography in emergency department patients with suspected pulmonary embolism.
abstract: OBJECTIVE
  To prospectively examine the diagnostic accuracy of two-dimensional transthoracic echocardiography (2-D echo) in emergency department (ED) patients being evaluated for acute pulmonary embolism (PE).
  
  
  METHODS
  This was a 14-month prospective observational trial of a convenience sample of ED patients undergoing evaluation for suspected PE at a suburban teaching hospital. The 2-D echo was defined as positive if any two of the following were noted: right ventricular dilation, abnormal septal motion, loss of right ventricular contractility, elevated pulmonary artery or right ventricular pressures, moderate to severe tricuspid regurgitation, or visualization of a clot seen in the right ventricle or pulmonary artery. The patient was considered to have a PE if one of the following was positive: a pulmonary angiogram, contrast helical computed tomography, a magnetic resonance angiogram, a high-probability ventilation/perfusion (V/Q) scan without contradictory evidence, or an intermediate-probability V/Q scan with ultrasonic evidence of deep venous thrombosis.
  
  
  RESULTS
  Of 225 cases identified, 39 met the defined criteria for PE (17%). A 2-D echo was performed on 124 patients (55%), of whom 27 (22%) had PE. In 20 patients the 2-D echo had at least two indicators of right ventricular strain; however, only 11 of these patients had confirmed pulmonary embolus. The 2-D echo had a sensitivity of 0.41 (95% CI = 0.32 to 0.49) and a specificity of 0.91 (95% CI = 0.86 to 0.96). The likelihood ratio positive was a moderately strong 4.4, with a weak likelihood ratio negative of 0.6.
  
  
  CONCLUSIONS
  Bedside 2-D echo is not a sensitive test for the diagnosis of PE in ED patients. Positive findings moderately increase the suspicion for PE but are not diagnostic.
authors.affiliation: Department of Emergency Medicine, Division of Cardiology, William Beaumont Hospital, Royal Oak, MI, USA. rjerdoc@aol.com
authors.forename: R E
authors.initials: RE
authors.lastname: Jackson
authors.forename: R R
authors.initials: RR
authors.lastname: Rudoni
authors.forename: A M
authors.initials: AM
authors.lastname: Hauser
authors.forename: R G
authors.initials: RG
authors.lastname: Pascual
authors.forename: M E
authors.initials: ME
authors.lastname: Hussey
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014463:Ultrasonography