Prolonged QT Interval Corrected for Heart Rate During Diabetic Ketoacidosis in Children

Prolonged QT Interval Corrected for Heart Rate During Diabetic Ketoacidosis in Children
June 2008
Nathan Kuppermann, MD, MPH; Jeanny Park, MD; Kathryn Glatter, MD; James P. Marcin, MD, MPH; Nicole S. Glaser, M
Archives of Pediatrics & Adolescent Medicine

Objective To evaluate the effect of diabetic ketoacidosis (DKA) on the QT interval corrected for heart rate (QTc) in children. Ketosis occurs in several conditions, including DKA and alcoholic ketoacidosis, and during use of very low-carbohydrate diets. Prolongation of the QTc has been described in a few children receiving ketogenic diets, but cardiac effects of ketosis have not otherwise been investigated.

Design For this observational study, 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 and correlated QTc with clinical variables.

Setting The pediatric emergency department and intensive care unit of an academic medical center.

Patients Thirty children with type 1 diabetes mellitus and DKA.

Main Outcome Measure The QTc during DKA.

Results The mean (SD) QTc during DKA was 450 (38) milliseconds (range, 378-539 milliseconds). After recovery from DKA, the mean (SD) QTc decreased to 407 (36) milliseconds (range, 302-485 milliseconds; difference, 43 milliseconds; 95% confidence interval, 23-63 milliseconds) (P < .001). Fourteen of the 30 children (47%) had prolonged QTc during DKA (range, 450-539 milliseconds). After recovery from DKA, only 4 children (13%) had persistent QTc prolongation (range, 451-485 milliseconds). The anion gap was significantly associated with QTc prolongation (correlation coefficient, 0.49; P = .006). Most patients had no electrolyte abnormalities or hypoglycemia to account for QTc prolongation.

Conclusions Prolonged QTc occurs frequently during DKA and is correlated with ketosis. Current guidelines regarding cardiac monitoring of children during DKA should be strictly followed, and electrocardiographic screening of patients with other ketotic conditions should be considered.

Author Affiliations: Departments of Emergency Medicine (Dr Kuppermann) and Pediatrics (Drs Kuppermann, Park, Marcin, and Glaser), and Division of Cardiology, Department of Internal Medicine (Dr Glatter), University of California, Davis, School of Medicine.

© 2008 American Medical Association. All Rights Reserved.

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