title: Echocardiographic assessment of obstructive lesions in atrioventricular septal defects.
abstract: OBJECTIVE
  We sought to determine the accuracy of transthoracic echocardiography (TTE) in identifying risk factors in patients with an atrioventricular septal defect (AVSD).
  
  
  BACKGROUND
  Atrioventricular septal defect is a common lesion, and many decisions about it are based on echocardiography alone. The identification of associated left-sided inflow and outflow obstructive lesions is important, as they are responsible for mortality and morbidity.
  
  
  METHODS
  Between 1983 to 1998, 549 patients with AVSD underwent repair. The TTE findings were correlated with surgery, angiocardiography, autopsy or postoperative TTE. Papillary muscle measurements were made in those with either a left ventricular outflow tract (LVOT) or left ventricular inflow abnormality and compared with those measurements from control subjects. Measurements of the LVOT were made in patients with an identified LVOT abnormality.
  
  
  RESULTS
  There were 63 missed lesions, decreasing over time. Double-orifice left atrioventricular valve (DOLAVV) and nonobstructive chordae in the LVOT were more often missed. Reoperation was performed to address a missed lesion in 2 of 68 patients. Two of 55 patients died of reasons related to a missed lesion. In 67% of patients, DOLAVV was missed. Abnormal papillary muscle angles were seen with either a LVOT abnormality or DOLAVV. High insertion of the anterolateral papillary muscle was a risk factor for death or residual LVOT obstruction. Abnormal LVOT measurements were found in patients with tunnel obstruction and those with an acquired subaortic ridge.
  
  
  CONCLUSIONS
  Transthoracic echocardiography provides accurate preoperative information on AVSD.
authors.affiliation: Department of Pediatrics, Hospital for Sick Children, University of Toronto, Ontario, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Sittiwangkul
authors.forename: R Y
authors.initials: RY
authors.lastname: Ma
authors.forename: B W
authors.initials: BW
authors.lastname: McCrindle
authors.forename: J G
authors.initials: JG
authors.lastname: Coles
authors.forename: J F
authors.initials: JF
authors.lastname: Smallhorn
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D006344:Heart Septal Defects, Atrial / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D006345:Heart Septal Defects, Ventricular / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D010210:Papillary Muscles / Q000473:pathology; D012189:Retrospective Studies; D012307:Risk Factors; D014463:Ultrasonography; D014694:Ventricular Outflow Obstruction / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology