Reference Values and Calculation of z-Scores of Echocardiographic Measurements of the Normal Pediatric Right Ventricle

• Normal pediatric RV dimensions were measured and z scores calculated in 576 healthy children and 37 children with hemodynamically relevant ASDs.
• This is the first study presenting normal ranges of RV systolic and diastolic dimensions in children from infancy to 18 years of age.
• RV z scores > 2 SDs were predictive for detecting ASD in patients <8 years of age with enlarged right ventricles.

Determination of right ventricular (RV) size and function has gained more interest in recent years in adults and children, especially in patients with congenital heart disease. Data on normal RV size parameters in children are scant. The aim of this study was to investigate growth-related changes in RV internal dimensions in a healthy pediatric cohort and the predictive value of RV parameters in identifying enlarged right ventricles in children with secundum-type atrial septal defects (ASD). A prospective study was conducted in a group of 576 healthy children (aged 1 day to 18 years) and 37 children (aged 1.4 to 17.7 years) with moderate-sized to large ASDs. The effects of age, body length, body weight, and body surface area were determined on the following RV parameters: end-diastolic basal diameter, end-diastolic midcavity diameter, end-diastolic length, end-systolic length, end-diastolic area, and end-systolic area. The predictive value of normal values stratified for age, body weight, body length, and body surface area was tested in children with ASDs. RV end-diastolic basal diameter, end-diastolic midcavity diameter, end-diastolic length, end-systolic length, end-diastolic area, and end-systolic area showed positive correlations with age, body length, body surface area, and body weight. In this population, RV z scores showed high specificity for detecting patients with ASDs, with sensitivity up to 89%, especially in children <8 years of age. In conclusion, the normal ranges of pediatric RV internal dimensions are provided. The z scores of these RV parameters were also calculated. Normal RV z scores might be important predictors in identifying enlarged right ventricles in patients with ASDs.