Corrected QT Interval in Children With Brain Death

Prolongation of the QT interval is a well-documented finding in adults with severe brain injury. However, QT prolongation has not been well documented in the pediatric population with brain injury. Our objective was to determine the range of QT intervals in children with the diagnosis of brain death, hypothesizing that the QT interval corrected for heart rate (QTc) is longer in this population than in a normal population. All previously healthy children (<18 years) dying in our hospital from 1995 to 2007 with a diagnosis of brain death and at least one electrocardiogram (ECG) with normal anatomy by echocardiogram were included. Admission details, past medical and family history, demographic data, and laboratory data were collected. The QT and preceding RR intervals from three sinus beats on a standard 12-lead ECG were measured. The QTc was calculated with the Bazett method, and the values were averaged. Thirty-seven patients met inclusion criteria. Five had event histories concerning for possible underlying rhythm disturbances; data analysis was performed with and without these patients. The QTc data were normally distributed. The mean (SD) QTc for the entire cohort was 452 (61) ms. Excluding the five patients, it was 449 (62) ms. On multivariate analysis, sex (QTc female < male) and hypokalemia were associated with QTc prolongation. QTc in children with brain death is normally distributed but significantly longer than QTc in normal children. Until rapid genetic testing for channelopathies is universally available, our findings suggest that potential pediatric cardiac donors with isolated prolongation of the QTc in this setting may be acceptable in the absence of other exclusionary criteria.