Regression Equations for Calculation of Z Scores of Cardiac Structures in a Large Cohort of Healthy Infants, Children, and Adolescents: An Echocardiographic Study

Background: Decision making in the care of pediatric patients with congenital and acquired heart disease remains reliant on detailed measurements of cardiac structures using 2-dimensional echocardiography. Calculated z scores are often used to normalize these measurements to the patient's body size. Existing normal data in the literature are limited by small sample size, small numbers of measured cardiac structures, and inadequate data for the calculation of z scores. Accordingly, we sought to develop normative data in a large pediatric cohort using modern echocardiographic equipment from which z scores could be calculated. Methods: Two-dimensional and M-mode echocardiography was performed in 782 patients ranging in age from 1 day to 18 years. Measurements were made of 21 individual cardiac structures. Regression equations were derived to relate the size of the various cardiac structures to body surface area. Data are presented graphically, and regression equations are derived relating cardiac dimension to body surface area. Conclusion: The presented data will allow the calculation of z scores for echocardiographically measured cardiac structures. This information will be valuable for clinicians caring for infants and children with known or suspected cardiac disease.