title: Geometry of the left ventricular outflow tract in fixed subaortic stenosis and intact ventricular septum: an echocardiographic study in children and adults.
abstract: OBJECTIVE
  We compared the echocardiographic geometry of the preoperative and postoperative left ventricular outflow tract in children and adults with isolated fixed subaortic stenosis with age- and weight-matched controls to elucidate whether the geometry can be modified when surgical intervention is performed at a younger age.
  
  
  METHODS
  The mitral-aortic valve distance, aortic valve diameter, aorto-left ventricular septal angle, degree of aortic valve dextroposition, aortic valve-subaortic stenosis distance, width of left ventricular outflow tract, left ventricle wall thickness, and septal thickness were determined preoperatively and postoperatively in 21 patients and 21 controls. The measurements were indexed to body surface area. Patients were divided into 3 age groups: group 1 comprised 9 patients aged 1 to 10 years, group 2 comprised 8 patients aged 11 to 20 years, and group 3 comprised 4 patients aged 21 years or more.
  
  
  RESULTS
  Compared with controls, patients had a significantly wider mitral-aortic separation (group 1, P = .003; group 2, P = .02), a steeper aortoseptal angle (group 1, P = .02; group 3, P = .03), a smaller left ventricular outflow tract width (group 1, P = .003; group 2, P = .01), a marked aortic valve dextroposition (groups 1 and 3), an increased left ventricle wall thickness (group 1, P = .03), and an increased septal thickness (group 1, P = .01). There was a significant difference between preoperative and postoperative values in aortoseptal angle and left ventricular outflow tract width in patients up to 10 years of age (P = .02 and P = .01, respectively).
  
  
  CONCLUSIONS
  Hearts with isolated subaortic stenosis have abnormal left ventricular outflow tract geometry that postoperatively showed changes in left ventricular outflow tract width and aortoseptal angle. Compared with controls, the aortoseptal angle does not "normalize" when surgery is performed in older patients, suggesting that left ventricular outflow tract geometry may be remodeled in younger patients.
authors.affiliation: Department of Pediatrics, Royal Brompton Hospital and Imperial College, London, United Kingdom. r.barkhordarian@imperial.ac.uk
authors.forename: Reza
authors.initials: R
authors.lastname: Barkhordarian
authors.forename: Ding
authors.initials: D
authors.lastname: Wen-Hong
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Manjit
authors.initials: M
authors.lastname: Josen
authors.forename: Michael
authors.initials: M
authors.lastname: Henein
authors.forename: Siew Yen
authors.initials: SY
authors.lastname: Ho
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D021922:Discrete Subaortic Stenosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology; D006346:Heart Septum / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D007223:Infant; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000473:pathology; D014463:Ultrasonography; D014694:Ventricular Outflow Obstruction / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology