Prevalence of Prolonged QTc Interval and Its Association with Disease Severity in Pediatric Diabetic Ketoacidosis: A Retrospective Cross-Sectional Study in a Tertiary Care Center

Background Diabetic ketoacidosis (DKA) is a life-threatening complication of type 1 diabetes mellitus in children, characterized by profound metabolic disturbances. Among these, prolongation of the corrected QT (QTc) interval is a significant cardiac abnormality associated with increased risk of arrhythmias and sudden cardiac death. This study aimed to assess the prevalence of QTc prolongation and its correlation with DKA severity in pediatric patients. Methods We conducted a retrospective cross-sectional study involving 100 children under 18 years of age admitted with DKA to Motahari Hospital in Urmia, Iran. DKA severity was determined using arterial blood gas analysis. QTc intervals were calculated from admission electrocardiograms and categorized as prolonged or normal. The relationship between QTc status and biochemical parameters—arterial pH, serum bicarbonate (HCO₃⁻), and partial pressure of CO₂ (PCO₂)—was analyzed. Results QTc prolongation was detected in 17% of the study population. Patients with prolonged QTc exhibited significantly lower arterial pH (6.96 ± 0.15) and serum bicarbonate (4.62 ± 2.26 mmol/L) compared to those with normal QTc (pH 7.09 ± 0.22, HCO₃⁻ 7.22 ± 3.53 mmol/L; p = 0.018 and p = 0.005, respectively). PCO₂ levels were higher in the prolonged QTc group (20.10 ± 7.02 mmHg vs. 15.5 ± 5.95 mmHg, p = 0.021). QTc duration increased with DKA severity, and 27.5% of patients with severe DKA had prolonged QTc intervals. Conclusion QTc prolongation is relatively frequent in pediatric DKA and correlates strongly with disease severity. Early ECG monitoring may help identify high-risk patients and guide timely interventions to prevent serious cardiac complications.