Nomograms for echocardiographic right ventricular sub-costal view dimensions in healthy Caucasian children: A new approach to measure the right ventricle

BACKGROUND: The sub-costal examination of the heart is part of routine examination in pediatric echocardiography, and has the advantage to visualize also the infundibulum part of the right ventricle (RV). Despite this fact, currently nomograms for sub-costal RV dimensions are lacking. METHODS: We prospectively studied healthy Caucasian Italian children by two-dimensional echocardiography. Measurements included: sub-costal end diastolic basal-apical and latero-lateral diameters, end diastolic and end systolic area, 4 chamber end diastolic and end systolic area and length, end diastolic basal (RV1) and mid-cavity (RV2) diameters. Age, weight, height, heart rate (HR), and body surface area (BSA) were used as independent variables in different analyses to predict the mean values of each measurement. Structured Z scores were then computed. Agreement of RV diameters and areas in subcostal view and 4-chamber view were investigated. RESULTS: 732 subjects (age 0 days-17 years; 48% female; BSA 0.12-2.12 m2) were studied. The Haycock formula was used when presenting data as predicted values (mean ± 2 SDs) for a given BSA and within equations relating echocardiographic measurements to BSA. The predicted values and Z-score boundaries for all measurements are presented. Excellent correlations were found among two-dimensional diameters and area calculated in sub-costal view with those evaluated in 4-chamber view. CONCLUSIONS: We report echocardiographic nomograms for RV diameters and areas measured in the sub-costal view. Our data may implement normative data for 2D echocardiography evaluation of the RV in children.