Echocardiographic nomograms for left ventricular parameters in 13,454 infants

Abstract Background Cardiac dimensions and function are key parameters in the management of children with cardiopulmonary abnormalities and are important predictors of clinical outcome. In particular, left ventricular (LV) dimensions and function are important predictors of clinical outcome and prognosis. In pediatric echocardiography, nomograms are essential in the separation of normal variation from pathological conditions and ascertaining normal growth. However, data from cohorts of newborns are limited, and current nomograms remain an insufficient approximation of the range of values that should be considered normal. Purpose We developed nomograms and Z scores for two-dimensional echocardiographic measurements of LV structure and function in a large group of healthy newborns. Methods Our study population included newborns from a large population study of newborns (n >25,000) who were born at term to healthy mothers, had a systematic transthoracic echocardiogram (TTE) performed within 30 days of birth, and with no signs of any major congenital heart diseases. We developed nomograms for 10 LV parameters by modelling these parameters as a function of body surface area (BSA) through joint modelling of the mean, standard deviation, skewness, and kurtosis. We then evaluated the impact of infant sex and age at time of echocardiography on the model fit. Results The 13,454 infants in the study population (48.5% females), had a median age of 12 days at TTE for both boys and girls (interquartile range IQR 8–15 and 8–12 days, respectively), and a median BSA of 0.23 m2 (IQR 0.22 m2 - 0.24 m2). All nomograms had acceptable goodness-of-fit within strata of sex. In contrast, model fit was worse for infants examined <7 days of age, compared with those examined from 7 to 30 days of age, necessitating the creation of separate nomograms for the two age groups. Examples of the plotted Z scores of one of the 10 LV parameters is shown in the figure. Conclusions We provide a large normative dataset and Z scores for echocardiographic measures of LV structure and function in neonates. Normative data is crucial in the management of patients with heart disease and these results provide a needed tool for evaluation of LV size and function in the newborn population.Plotted Z scores of the IVSd