Recently, Kuppermann et al1 described prolonged QT intervals corrected for heart rate (QTc) during diabetic ketoacidosis (DKA) in 30 children with type 1 diabetes mellitus. These findings contrast with a convincing investigation2 published 20 years ago in which, after 24 hours of continuous electrocardiogram (ECG) monitoring, it was concluded that ECG changes were rare and insignificant during the treatment of adults with DKA. In addition, a consensus statement from the American Diabetes Association3 has only connected changes in QT interval during DKA to hypokalemia (widening) and to hyperkalemia (shortening) in children. Clearly, in Kuppermann and colleagues' work, the reported QTc prolongation could not be related to hypokalemia because only 4 of the 14 children with long QTc had hypokalemia. While a connection between QTc prolongation and ketosis could be a plausible explanation, it is also possible that the findings are primarily associated with the psychological stress associated with DKA.
Szabo A, Andrássy G. Prolonged QT Interval Corrected for Heart Rate During Diabetic Ketoacidosis in Children: Psychological Stress Could Be Another Explanation. Arch Pediatr Adolesc Med. 2009;163(1):92-93. doi:10.1001/archpediatrics.2008.519