title: S3 detection as a diagnostic and prognostic aid in emergency department patients with acute dyspnea.
abstract: OBJECTIVE
  Dyspneic emergency department (ED) patients present a diagnostic dilemma. Recent technologic advances have made it possible to capture information about pathologic heart sounds at ECG recording. This study evaluates the effect of an S3 captured by acoustic cardiography on emergency physician diagnostic accuracy and confidence in their diagnosis of acute decompensated heart failure, as well as the patient's prognosis.
  
  
  METHODS
  Dyspneic ED patients older than 40 years who were not dialysis dependent were prospectively enrolled in this multinational study. Treating emergency physicians, initially blinded to all laboratory and acoustic cardiography results, estimated acute decompensated heart failure probability from 0% to 100% on a visual analog scale. The emergency physician repeated the visual analog scale after acoustic cardiography results were provided. Physician diagnostic accuracy for and confidence in acute decompensated heart failure were evaluated against a reference standard diagnosis, as determined by 2 independent cardiologists blinded to acoustic cardiography. Patients were followed through 90 days to determine the relationship of the S3 to adverse events.
  
  
  RESULTS
  Nine hundred ninety-five patients with acoustic cardiography results were enrolled from March to October 2006 at 7 US and 2 international sites. Median age was 63 years, 55% were men, and 44% were white. The reference diagnosis was acute decompensated heart failure in 41.5%. After initial history and physical examination, the treating physician's initial sensitivity, specificity, and accuracy for acute decompensated heart failure as a possible diagnosis were 89.0% (95% confidence interval [CI] 85.5% to 91.8%), 58.2% (95% CI 54.0% to 62.2%), and 71.0% (95% CI 68.4% to 73.8%), respectively. Acoustic cardiography had an accuracy of 68% (95% CI 65.4% to 71.3%), sensitivity of 40.2% (95% CI 35.5% to 45.1%), and specificity of 88.5% (95% CI 85.5% to 90.9%). Emergency physician confidence and diagnostic accuracy were influenced by adding information about the presence or absence of S3. In a multivariable model, the S3 added no independent prognostic information for 30-day (odds ratio 1.20; 95% CI 0.67 to 2.14) or 90-day events (odds ratio 1.22; 95% CI 0.78 to 1.90).
  
  
  CONCLUSIONS
  In patients presenting with acute dyspnea, the acoustic cardiography S3 was specific for acute decompensated heart failure and affected physician confidence but did not improve diagnostic accuracy for acute decompensated heart failure, largely because of its low sensitivity. Further, the acoustic cardiography S3 provided no significant independent prognostic information.
authors.affiliation: Department of Emergency Medicine, University of Cincinnati, OH 45267-0769, USA. sean.collins@uc.edu
authors.forename: Sean P
authors.initials: SP
authors.lastname: Collins
authors.forename: W Frank
authors.initials: WF
authors.lastname: Peacock
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Lindsell
authors.forename: Paul
authors.initials: P
authors.lastname: Clopton
authors.forename: Deborah B
authors.initials: DB
authors.lastname: Diercks
authors.forename: Brian
authors.initials: B
authors.lastname: Hiestand
authors.forename: Chris
authors.initials: C
authors.lastname: Hogan
authors.forename: Michael C
authors.initials: MC
authors.lastname: Kontos
authors.forename: Christian
authors.initials: C
authors.lastname: Mueller
authors.forename: Richard
authors.initials: R
authors.lastname: Nowak
authors.forename: Wen-Jone
authors.initials: WJ
authors.lastname: Chen
authors.forename: Chien-Hua
authors.initials: CH
authors.lastname: Huang
authors.forename: William T
authors.initials: WT
authors.lastname: Abraham
authors.forename: Ezra
authors.initials: E
authors.lastname: Amsterdam
authors.forename: Tobias
authors.initials: T
authors.lastname: Breidthardt
authors.forename: Lori
authors.initials: L
authors.lastname: Daniels
authors.forename: Ayesha
authors.initials: A
authors.lastname: Hasan
authors.forename: Mike
authors.initials: M
authors.lastname: Hudson
authors.forename: James
authors.initials: J
authors.lastname: McCord
authors.forename: Tehmina
authors.initials: T
authors.lastname: Naz
authors.forename: Lynne E
authors.initials: LE
authors.lastname: Wagoner
authors.forename: Alan
authors.initials: A
authors.lastname: Maisel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002983:Clinical Competence; D004417:Dyspnea / Q000209:etiology; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods*; D004636:Emergency Service, Hospital; D005260:Female; D005500:Follow-Up Studies; D006326:Heart Auscultation; D006333:Heart Failure / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010701:Phonocardiography; D010808:Physical Examination; D011446:Prospective Studies; D012372:ROC Curve