Age-specific reference intervals for indexed left ventricular mass in children.

BACKGROUND In older children, one of the standards for indexing left ventricular mass (LVM) is height raised to an exponential power of 2.7. The purpose of this study was to establish a normal value for the pediatric age group and to determine how, if at all, LVM/height(2.7) varies in children. METHODS M-mode echocardiography was performed in 2,273 nonobese, healthy children (1,267 boys, 1,006 girls; age range 0-18 years). Curves were constructed for the 5th, 10th, 25th, 50th, 75th, 90th, and 95th quantiles of LVM/height(2.7). RESULTS In children aged > 9 years, median LVM/height(2.7) ranged from 27 to 32 g/m(2.7) and had little variation with age. However, in those aged < 9 years, LVM/height(2.7) varied significantly, and percentiles for newborns and infants were approximately double the levels for older children and adolescents: the 95th percentile ranged from 80 g/m(2.7) for newborns to 40 g/m(2.7) for 11-year-olds. CONCLUSION For patients aged > 9 years, quantiles of LVM/height(2.7) vary little, and values > 40 g/m(2.7) in girls and > 45 g/m(2.7) in boys can be considered abnormal (ie, > 95th percentile). However, for patients aged < 9 years, the index varies with age, and therefore, measured LVM/height(2.7) must be compared with percentile curves, which are provided. This variation in LVM/height(2.7) in younger children indicates that a better indexing method is needed for this age group. Nevertheless, these data are valuable in that they provide normal values with which patient data can be compared.