Medical Preconditioning in Infants and Young Children with Secundum Atrial Septal Defect: Effects of Preload and Afterload Reduction on Defect Size and Right Ventricular Remodeling

Abstract Objectives: To evaluate the effects of preload reduction using furosemide and combined preload–afterload reduction therapy using furosemide plus captopril on atrial septal defect (ASD) secundum size, right ventricular (RV) dimensions, and cardiac remodeling in infants and young children over a one-year follow-up period. Patients & Methods: This prospective, non-randomized controlled study included 90 infants and young children with isolated secundum ASD. Patients were allocated into three equal groups: Group I receivedf urosemide, Group II received furosemide plus captopril, and Group III served as untreated controls. Clinical, anthropometric, and echocardiographic assessments were performed at baseline, 6 months, and 12 months. Primary outcomes were changes in ASD diameter and RV size. Secondary outcomes included left ventricular ejection fraction (EF), fractional shortening (FS), tricuspid annular plane systolic excursion (TAPSE), TAPSE Z-score, and TAPSE/ESPAP ratio. Statistical analysis included ANOVA, Kruskal–Wallis, paired tests, and post hoc comparisons Results: Baseline characteristics were comparable among the three groups. After 12 months, ASD size differed significantly between groups (P < 0.001). The mean reduction in ASD size from baseline to one year was greatest in Group II (3.4 ± 5.5 mm), followed by Group I (1.31 ± 4.3 mm), whereas Group III showed minimal change (0.32 ± 2.5 mm; P = 0.004). Post hoc analysis demonstrated significant differences between Group II and Group III (P = 0.001) and between Group I and Group III, while the difference between Groups I and II showed a trend toward significance (P = 0.05). RV diameter decreased significantly in both treated groups at 6 and 12 months (P < 0.001) but remained persistently dilated in untreated controls. EF showed a mild but statistically significant improvement in treated groups compared with controls. TAPSE and TAPSE Z-scores improved significantly over time in all groups, with no significant intergroup differences. Conclusion: .The use of furosemide, alone or with captopril, significantly were associated with ASD size reduction and favorable right ventricular remodeling in infants and young children with secundum ASD, providing effective medical bridging strategy to transcatheter closure.