Cardiovascular Involvement in Children with Type 1 Diabetes Mellitus: Insights from Cardiac Electrophysiological Balance and Electrocardiographic Parameters

Objective: We examined whether children with type 1 diabetes mellitus (T1DM) demonstrated early, subclinical electrical alterations on electrocardiography by evaluating dispersion indices, ventricular repolarization markers, and electrophysiological balance measures. Methods: In this prospective case–control study, 20 children with T1DM and 20 age- and sex-matched healthy controls underwent transthoracic echocardiography and 12-lead electrocardiogram (ECG). We quantified P-wave, QTc, and Tp–e dispersion; Tp–e/QT and Tp–e/QTc ratios; and electrophysiological balance indices (QT/QRS and QTc/QRS). Relationships between ECG indices and clinical variables (diabetes duration and glycated hemoglobin [HbA1c]) were assessed. Results: Conventional echocardiographic parameters were normal in both groups. Compared with controls, children with T1DM had higher P-wave dispersion, QTc dispersion, and Tp–e dispersion (all p<0.001), whereas Tp–e-based ratios and electrophysiological balance indices were similar between groups. Diabetes duration correlated positively with P-wave dispersion (r=0.489, p=0.029), and HbA1c correlated inversely with QT/ QRS (r=-0.475, p=0.034). Conclusion: Pediatric T1DM may be accompanied by subtle ECG abnormalities despite preserved conventional echocardiographic findings. Increased dispersion indices support early electrical heterogeneity, and the association between electrophysiological balance and glycemic control suggests an effect of metabolic burden on myocardial electrical stability.