title: A novel method of expressing left ventricular mass relative to body size in children.
abstract: BACKGROUND
  Left ventricular (LV) hypertrophy (LVH) in children is widely defined as a left ventricular mass index (LVMI, g/m(2.7)) >95th percentile. However, LVMI increases with decreasing height in young children; thus, the 95th percentile LVMI will depend on the height distribution of the reference population. The objective of this study was to compare the performance of a novel method of expressing LV mass relative to body size (centile curves) with the LVMI method.
  
  
  RESULTS
  LV mass was estimated by M-mode echocardiography in 440 healthy nonobese reference children (birth to 21 years) and 239 children at risk for LVH; the LVMI was calculated for all children. Three samples of 270 children, each with different height distributions, were drawn from the reference population. A sample-specific 95th percentile LVMI was determined for each reference sample. At-risk children were classified as having LVH or not based on each sample-specific 95th percentile. Four LV mass-for-height centile curves were constructed with the Cole lambda-mu-sigma method and data from each reference sample. At-risk children were each assigned an LV mass-for-height percentile with these curves and were reclassified as having LVH if LV mass-for-height was >95th percentile. The centile method provided a stable estimate of the proportion of at-risk children with LVH regardless of reference group, whereas proportion estimates varied significantly depending on the reference population when the LVMI method was used.
  
  
  CONCLUSIONS
  LV mass-for-height centile curves are superior to LVMI as a method of normalizing LV mass to body size in children.
authors.affiliation: Department of Pediatrics, Montreal Children's Hospital, Hospital, McGill University, Montreal, Quebec H3H 1P3, Canada. beth.foster@muhc.mcgill.ca
authors.forename: Bethany J
authors.initials: BJ
authors.lastname: Foster
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Mackie
authors.forename: Mark
authors.initials: M
authors.lastname: Mitsnefes
authors.forename: Huma
authors.initials: H
authors.lastname: Ali
authors.forename: Silvia
authors.initials: S
authors.lastname: Mamber
authors.forename: Steven D
authors.initials: SD
authors.lastname: Colan
mesh_terms: D000293:Adolescent; D001827:Body Height; D049628:Body Size; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000379:methods* / Q000592:standards*; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000453:epidemiology; D007223:Infant; D008297:Male; D010372:Pediatrics; D012015:Reference Standards; D012016:Reference Values; D012307:Risk Factors