Electrocardiographic Findings in Children with Beta-Thalassemia Major: A Case-Control Study of the Impact of Age, Sex, and Body Mass Index

Abstract

Background: β-Thalassemia major (TM) is a severe hereditary hemoglobinopathy characterized by chronic anemia and transfusion-related iron overload, leading to significant cardiovascular morbidity. Objectives: This study aimed to comprehensively assess electrocardiographic (ECG) parameters in pediatric patients with TM, compared with healthy controls, and to evaluate the impact of demographic factors on cardiac electrical remodeling. Methods: This case-control study included 45 children and adolescents with TM and 45 age- and sex-matched healthy controls. Standard 12-lead ECGs were performed to analyze heart rate, PR interval, QRS duration, QT interval, corrected QT (QTc), QT dispersion (QTd), the T-peak to T-end interval (Tpe), and Tpe-derived ratios (Tpe/QT and Tpe/QTc). Demographic and anthropometric data were recorded. Statistical analyses were conducted to compare the groups and identify correlations within the TM cohort. Analyses were performed using SPSS, with a significance level of 0.5. Results: Children in the TM group were the same age as those in the control group (P < 0.05). Electrocardiographic analysis revealed a significant atrioventricular conduction delay, as evidenced by prolonged PR intervals (P = 0.014). Furthermore, patients with TM demonstrated marked ventricular repolarization abnormalities, with significantly higher QT, QTc, QTd, Tpe, Tpe/QT, and Tpe/QTc values than controls (most P < 0.001), indicating increased electrical instability. Within the TM group, underweight patients had significantly lower systolic blood pressure and smaller aortic dimensions. Female patients had higher diastolic blood pressure, whereas age-based comparisons showed a smaller systolic aortic diameter in younger children. Conclusions: Pediatric patients with β-thalassemia major exhibit significant abnormalities in ECG repolarization markers, particularly prolonged Tpe and increased Tpe/QTc ratios, compared with those in healthy controls, indicating increased ventricular electrical instability and supporting the need for early and regular cardiac monitoring in this population.