[Reference values (Z-score) of inlet and trabecular portion diameters of the right ventricle: First description in Spanish healthy children]. / Valores de referencia (Z-score) de diámetros de porción de entrada y trabecular del ventrículo derecho: primera descripción en población pediátrica española sana.

INTRODUCTION AND OBJECTIVES: Right ventricle (RV) measurements are crucial for certain congenital heart diseases and various cardiovascular conditions. Echocardiographic RV diameters are especially useful for its assessment. Paediatric echocardiographic data standardisation in normal subjects is complex, scarce, and heterogeneous. The aim of this study was to establish reliable and reproducible echocardiographic reference values (Z-score) of RV diameters in a healthy Spanish paediatric cohort. METHODS: A multicentre study was conducted on 661 healthy subjects (age range 0-18 years, 43.5% female). Several regression models were tested to examine the relationship between RV diameters and biometric variables. Heteroscedasticity and residual associations (Shapiro-Wilk and Breusch-Pagan tests) and confounding factors (gender, age, inter/intraobserver agreement) were considered for an unbiased standardisation. RESULTS: Structured Z-scores were computed for each RV diameter. Predicted mean value for each diameter was determined according to age, weight, height, and different body surface area. The Haycock formula provided the best fit for basal, midcavity, and longitudinal diameters (R2 0.81; 0.82; 0.9). Confounders were not significant, and therefore not included in final models (inter/intraobserver agreement > 0.9). CONCLUSIONS: This study reports reference values for echocardiographic RV diameters from a Spanish healthy paediatric cohort using a rigorous statistical design. These Z-scores partly cover a gap in current paediatric cardiology and represent a relevant diagnostic tool for clinical practice, as well as a useful guide to decision making at any paediatric stage.