Reference values of the right ventricular outflow tract systolic excursion in 711 healthy children and calculation of z-score values

Abstract

Quantitative determination of right ventricular (RV) function has gained more interest over the last years. The RV outflow tract systolic excursion (RVOT SE) has been recently proposed as an echocardiographic tool to assess RV systolic function in adults. We aimed to determine growth-related changes of RVOT SE in children and to establish references values. A prospective study was conducted in a group of 711 healthy paediatric patients (age: 1 day to 18 years). We determined the effects of age and body surface area (BSA) on RVOT SE values. RVOT SE values were further correlated with the established RV systolic function parameters tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular peak systolic velocity (S'). The RVOT SE ranged from a mean of 3.4 mm in neonates to 9.5 mm in 18-year-old adolescents. The RVOT SE values showed a positive correlation with age (r = 0.90, P < 0.001) and BSA (r = 0.91, P < 0.001). A significant positive correlation was seen between RVOT SE and TAPSE (r = 0.93, P < 0.001) and also between RVOT SE and S' (r = 0.86, P < 0.001) in our patients. RVOT SE provides a simple measure and, in combination with long-axis excursion parameters TAPSE and S', a comprehensive assessment of RV systolic function. Z-scores of RVOT SE values were calculated, and percentile charts were established to serve as reference data.