Alberto Guevara-Tirado, Facultad de Ciencias de la Salud, Universidad Científica del Sur, Lima, Perú
Background: In pediatrics, body surface area (BSA) influences cardiac structure, yet the intermediate mechanisms linking somatic growth and ventricular dimensions remain insufficiently explored. The objective was to analyze the relationship between BSA and left ventricular volumes in pediatric population, evaluating the mediating role of echocardiographic variables. Methods: Analytical cross-sectional study using a secondary database from the public Pediatric Heart Network repository, consisting of 2,383 individuals under 18 years of age. Exposure was BSA (Haycock formula). Outcomes were left ventricular end-diastolic area (LVEDA) and end-systolic area (LVESA). Mediators included proximal transverse aortic arch diameter (AAPTAD), mitral valve annulus diameter (MVAVD), and main pulmonary artery diameter (MPA). Serial mediation models (model 6, Hayes’ PROCESS macro) with 5,000-sample bootstrap were applied, adjusting for age, sex, and ethnicity. A schematic diagram was developed to represent mediated pathways. Results: BSA showed a strong direct effect on LVEDA and LVESA. Relevant indirect effects were identified (4.22 and 1.96, respectively). The strongest mediation was through the mitral valve diameter (2.12 in LVEDA, 1.08 in LVESA), followed by the MVAVD → MPA pathway (0.56 and 0.16). The pulmonary artery also contributed (0.54 and 0.16), while proximal ascending aorta effects were smaller (0.26 and 0.28). Conclusions: BSA influences pediatric ventricular volumes through both direct and indirect effects, with the mitral valve, pulmonary artery, and ascending aorta acting as key mediators.
Keywords: Body surface area. Heart ventricles. Aorta. Pulmonary artery. Echocardiography. Models. Cardiovascular.