Basal-Predominant Right-Ventricular Dysfunction in Pediatric Dilated Cardiomyopathy: An Integrated Biventricular Strain Analysis

<b>Background:</b> Right-ventricular (RV) involvement is starting to gain recognition in pediatric dilated cardiomyopathy (DCM), but its deformation characteristics and its relationship to functional status remain insufficiently defined. <b>Methods:</b> Twenty-nine children with primary DCM were compared with age- and sex-matched healthy controls. Conventional echocardiography and two-dimensional speckle-tracking echocardiography (2D-STE) were performed. Segmental deformation (basal, mid-ventricular and apical levels) was analyzed using a linear mixed-effects model. Associations between strain indices and advanced functional limitation (NYHA/Ross Class III-IV) were evaluated using exploratory logistic regression and ROC analysis. <b>Results:</b> Children with DCM showed significant impairment in both ventricles. Conventional parameters (TAPSE, tricuspid E/A ratio, RV E' velocity, and LV ejection fraction) were reduced. Right ventricular strain was significantly lower in DCM compared with controls (<i>p</i> < 0.05). Segmental analysis demonstrated a basal-predominant reduction in RV strain. Right-ventricular free-wall longitudinal strain correlated with RV S' (r = -0.49), RV E' (r = -0.46), LVGLS (r = 0.79) and LV ejection fraction (r = -0.63, all <i>p</i> < 0.05). In univariable analysis, RVFWSL predicted advanced functional class (OR 1.13 per 1% decrease, <i>p</i> = 0.026), while LVGLS remained the independent predictor in the multivariable model. A combined model incorporating RVFWSL and LVGLS demonstrated excellent discriminative accuracy (AUC 0.95). <b>Conclusions:</b> Pediatric DCM is characterized by RV involvement with a distinct basal-dominant deformation pattern. Biventricular strain assessment improves the identification of children with advanced functional class and may enhance functional stratification beyond conventional indices.