title: Accuracy of echocardiography for detection of aortic arch obstruction after stage I Norwood procedure.
abstract: BACKGROUND
  Echocardiography has been widely used in postoperative assessment after stage I Norwood procedure, but its accuracy in detecting aortic arch obstruction (AAO) has not been determined. This study was designed to determine the accuracy of echocardiography in the diagnosis of AAO after stage I Norwood procedure, identify echocardiographic predictors of arch obstruction, and examine the time course of its development.
  
  
  METHODS
  The records and echocardiography reports of 139 patients who survived stage I Norwood procedure were reviewed. Reference standard for the diagnosis of AAO was catheterization, surgery, or autopsy.
  
  
  RESULTS
  AAO was diagnosed by reference standard criteria in 31 (22%) patients. Echocardiography correctly diagnosed AAO in 19 patients, missed the diagnosis in five, and wrongly predicted AAO in eight, yielding a 73% sensitivity, 92% specificity, 70% positive predictive value, and 88% accuracy. Moderate or severe right ventricular dysfunction, moderate or severe tricuspid regurgitation, and an abnormal abdominal aortic Doppler flow pattern were more common in patients with AAO. The probability of AAO developing within 6 months after stage I Norwood procedure was 21.1%, with a very small likelihood after that point. Beyond the first 30 days after surgery, the risk of death was higher in patients in whom AAO developed compared with those in whom it did not (relative risk 5.9, 95% confidence interval 2.7 to 13.2).
  
  
  CONCLUSIONS
  Echocardiography is a highly specific modality in detecting AAO after stage I Norwood procedure but its sensitivity is limited. Because of the increased risk of death associated with AAO and because most obstructions develop between 1 and 6 months postoperatively, early cardiac catheterization with possible intervention should be considered in patients with moderate or severe right ventricular dysfunction, moderate or sever tricuspid regurgitation, or an abnormal abdominal Doppler flow pattern during that period.
authors.affiliation: Department of Cardiology, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: A
authors.initials: A
authors.lastname: Fraisse
authors.forename: S D
authors.initials: SD
authors.lastname: Colan
authors.forename: R A
authors.initials: RA
authors.lastname: Jonas
authors.forename: K
authors.initials: K
authors.lastname: Gauvreau
authors.forename: T
authors.initials: T
authors.lastname: Geva
mesh_terms: D001015:Aortic Arch Syndromes / Q000000981:diagnostic imaging* / Q000453:epidemiology; D006328:Cardiac Catheterization; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000601:surgery*; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010166:Palliative Care; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000453:epidemiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors