Echocardiographic assessment of cardiac growth in children with structurally normal hearts.

Background: Early childhood is a critical window for cardiac development, yet the impact of prenatal factors and early growth patterns on heart structure and function in children with structurally normal hearts remains incompletely described. This study investigates the roles of birth weight (BW), gestational age (GA), birthweight-for-gestational-age (BW/GA) z-score, and weight gain z-score in shaping cardiac dimensions. Methods: In this longitudinal study we analyzed 1000 echocardiograms from 738 children aged 11 to 83 months. Results: Higher weight gain z-score was independently associated with smaller cardiac dimension z-scores, particularly in the aortic root, ascending aorta, left atrium diameter, left ventricular internal diameter at end-diastole, left ventricular internal diameter at end-systole, end-systolic volume, end-diastolic volume, and left ventricular mass. While birth characteristics influenced some cardiac parameters, postnatal weight gain emerged as a more significant predictor of cardiac size. Ejection fraction and fractional shortening were not influenced by the predictors in our analysis. Conclusions: Our findings suggest that postnatal weight gain was more consistently associated with cardiac structure z-scores than anthropometric characteristics at birth. Specifically, contractile myocardial thicknesses were relatively stable across weight gain patterns, whereas vascular structures showed inverse scaling with higher weight gain.