Prevalence of electrocardiographic abnormalities and predictors of QTc prolongation in patients with diabetic ketoacidosis: A retrospective cohort study

Objectives: To determine the prevalence of electrocardiographic (ECG) abnormalities in diabetic ketoacidosis (DKA) patients, evaluate their associations with metabolic parameters, and identify independent predictors of clinical outcomes. Methods: This retrospective study included 374 DKA patients (2012-2023). Baseline clinical characteristics, laboratory data, and initial ECG findings were analyzed. Multivariable logistic regression was performed to assess associations between metabolic parameters and corrected QT (QTc) prolongation, as well as clinical outcomes. Results: Sinus tachycardia occurred in 54.8%, while QTc prolongation was found in 64.7% of patients using Bazett’s formula versus 27.5% using Fridericia’s correction. In multivariable analysis, lower serum bicarbonate levels were independently associated with QTc prolongation using both formulas (Bazett’s: adjusted OR 0.92, 95%CI 0.87–0.98, p=0.007; Fridericia’s: adjusted OR 0.91, 95%CI 0.85–0.97, p=0.002). These associations remained consistent across different QTc thresholds, including high-risk and very high-risk QTc prolongation. However, QTc prolongation was not independently associated with length of stay or in-hospital mortality. Conclusions: QTc prolongation was frequently observed in patients with DKA and showed an association with the severity of metabolic acidosis, particularly reduced serum bicarbonate levels. Given its potential implication for arrhythmogenic risk, careful ECG assessment and monitoring should be considered during the initial evaluation and management of DKA.