Endocrine Abstracts

Introduction: Prolonged QT syndrome is defined as exceeding of the QT interval on the elecrocardiography (ECG) (> 450 ms in men and > 460 ms in women). It is either congenital or secondary to medication, electrolyte disturbances, heart disease. However, prolonged QT due to diabetic ketoacidosis (DKA) was rarely described. In this study, we tested the hypothesis that QTc prolongation occurs during DKA and returns to normal with resolution of ketosis.

Patients and Methods: A retrospective study to evaluate the effect of DKA on the QT interval corrected for heart rate. Our patients were followed in the Internal Medicine department of the regional hospital of Ben Arous within 4 years (2016–2019). We performed electrocardiography during DKA and after recovery. We measured QTc as the QT interval divided by the square root of the R-R interval.

Results: Among 112 patients with a prolonged QT interval on the ECG, 22 patients (19.64%) had DKA, including 12 women and 10 men. The mean age was 54 years (20–87 years). Eighteen patients were followed for type 2 diabetes and 4 patients were diagnosed with type 1 diabetes. There was no medical history of cardiac disease. At the ECG, the QT interval was prolonged with a mean duration of 481 ms (451–543 ms). Three patients were treated with furosemide in one patient, Chlorothiazide in one patient and Indapamide in another leading to a prolongation of the QT interval. Associated electrolyte disturbances were found in 3 patients: 2 cases with hypokalemia and another with hypocalcemia. After correction of DKA with insulin and rehydration, ECG control was normal.

Conclusion: The consistent association between various ketotic conditions and prolonged QTc and/or sudden death raises the question of whether ketosis may directly affect cardiac repolarization. Accurate QT measurement is imperative in DKA patients. Identifying associated electrolyte disturbances, drugs that prolong the QT interval can help reduce the risk of torscardiac arrythemia and sudden death in DKA.