A quantitative echocardiographic assessment is often essential for the management of congenital heart disease, especially in the first months of life. Despite this, pediatric echocardiographic nomograms are limited and heterogeneous, particularly for neonates and infants. The aim of this study was to establish reliable echocardiographic nomograms in a broad population of healthy Caucasian children.

Two-dimensional and M-mode measurements of 22 cardiovascular structures were performed. Models using linear, logarithmic, exponential, and square root relationships were tested. Heteroscedasticity was tested using the White and Breusch-Pagan tests. Age, weight, height, and body surface area (BSA; calculated using seven different formulas) were used as the independent variables in different analyses to predict the mean value of each echocardiographic measurement. Structured Z scores were then computed.

A total of 445 consecutive Caucasian Italian healthy subjects (age range, 0 days to 36 months; 49% female subjects) with BSAs ranging from 0.12 to 0.67 m² were prospectively enrolled. The calculation of BSA using the Haycock formula provided the best results, while other formulas either underestimated (DuBois, Mosteller, Dreyer, and Meban) or overestimated (Boyd and Gehan) BSA. The Haycock formula has been used when presenting data as predicted values (mean ± 2 SDs) for a given BSA and within equations relating echocardiographic measurements to BSA. For all the measurements, there was no significant intraobserver or interobserver variability.

The investigators report new, reliable echocardiographic Z scores derived from a large population of Caucasian neonates, infants, and toddlers calculated using a rigorous statistical design. These nomograms represent a valid diagnostic tool for echocardiographic quantification in this age group.