title: Measurement of effective aortic valve area using three-dimensional echocardiography in children undergoing aortic balloon valvuloplasty for aortic stenosis.
abstract: OBJECTIVE
  Pressure gradient is used for timing of balloon aortic valvuloplasty for aortic stenosis (AS) in children, but does not correlate well with outcome and is limited if ventricular function is poor. In adults, effective orifice area (EOA) is used to assess AS severity, but EOA by continuity equation or 2D echo is unreliable in children. Three-dimensional echocardiography (3DE) may reliably assess EOA but has not been studied in children. We assessed measurement of aortic valve EOA by 3DE in children with AS before and after balloon aortic valvuloplasty and compared results with change in aortic valve gradient.
  
  
  METHODS
  3DE was performed at time of catheterization before and after balloon aortic valvuloplasty. Using 3DE multiplanar review mode, valve annulus diameter, area, and EOA were measured and compared with change in aortic gradient and degree of aortic insufficiency.
  
  
  RESULTS
  Twenty-four 3DE studies in 12 children (mean age 4.4 ± 5.0 years) were analyzed. EOA was measurable in all. Catheter peak gradient decreased from 45 ± 10 to 26 ± 17 mmHg (P = 0.0018). 3DE EOA increased after balloon aortic valvuloplasty (0.59 ± 0.52 cm(2) vs 0.80 ± 0.70 cm(2) ; P = 0.03), without change in valve diameter. EOA change correlated with change in peak (r = 0.77; P = 0.005) and mean (r = 0.60; P = 0.03) aortic valve gradient post balloon aortic valvuloplasty.
  
  
  CONCLUSIONS
  3DE facilitates EOA measurement in pediatric AS and correlates with change in aortic valve gradient after balloon valvuloplasty.
authors.affiliation: The Labatt Family Heart Centre, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Tara
authors.initials: T
authors.lastname: Bharucha
authors.forename: Fernanda
authors.initials: F
authors.lastname: Fernandes
authors.forename: Cameron
authors.initials: C
authors.lastname: Slorach
authors.forename: Luc
authors.initials: L
authors.lastname: Mertens
authors.forename: Mark Kevin
authors.initials: MK
authors.lastname: Friedberg
mesh_terms: D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D002404:Catheterization / Q000379:methods*; D002675:Child, Preschool; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D006801:Humans; D007223:Infant; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome