title: Coronary artery Z score regression equations and calculators derived from a large heterogeneous population of children undergoing echocardiography.
abstract: BACKGROUND
  Clinical decision making in Kawasaki disease relies on measurements of the coronary arteries obtained by 2-dimensional echocardiography. Z scores relating measured values to independent variables are invaluable in ensuring the accurate and consistent treatment of patients with Kawasaki disease.
  
  
  METHODS
  The right coronary artery (RCA), left main coronary artery (LMCA), and left anterior descending (LAD) coronary artery were measured in 432 normal digital echocardiograms from a heterogeneous population of normal subjects aged 0 to 20 years. Linear regression analyses were performed relating the measurements to various functions of independent variables, including body surface area (BSA), height, and height. The adjusted R(2) and mean square error values were compared for each of the models, and the best model was chosen to create a Z score calculator.
  
  
  RESULTS
  Using the model ln(measurement) = beta(1) + beta(2) x ln(BSA), the adjusted R(2) values were 0.638, 0.702, and 0.708 for the RCA, LMCA, and LAD coronary artery models, respectively, with mean square error < 0.0402.
  
  
  CONCLUSIONS
  The calculation of accurate Z scores for coronary artery measurements in children can be accomplished using the Z-score calculator.
authors.affiliation: Division of Cardiology, Children's National Medical Center, Washington, DC, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Olivieri
authors.forename: Bob
authors.initials: B
authors.lastname: Arling
authors.forename: Mark
authors.initials: M
authors.lastname: Friberg
authors.forename: Craig
authors.initials: C
authors.lastname: Sable
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012016:Reference Values; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult