title: Early post-convulsive prolongation of QT time in children.
abstract: OBJECTIVE
  An important differential diagnosis of seizures in childhood is the long QT syndrome. Childhood epilepsy occurs about 400 times more often than long QT syndrome. We had observed children with slight post-convulsive prolongation of QT time more often than the reported incidence of long QT syndrome. We therefore conducted a prospective study to define the characteristics of post-convulsive prolongation of QT time in children.
  
  
  METHODS
  We investigated 30 consecutive infants and children (3 mo to 14 y) within 2 h after seizures. A follow-up ECG was obtained 1-9 d later. We also obtained ECGs from 30 healthy age- and gender-matched controls. We calculated the QT interval corrected for heart rate (QTc) by Bazett's formula in leads II, V5, V6, QT dispersion and the number of notched T waves.
  
  
  RESULTS
  We found a QTc interval of more than 440 ms in one or more leads in the first ECG in seven of 30 infants and children compared to 1 of 30 in the follow-up ECG (p=0.0003) and two of 30 in the healthy controls (p=0.14). Average QTc was higher for all leads in the first ECG. This was statistically significant in leads II (414 vs 402 ms, p=0.008), V5 (416 vs 404 ms, p=0.002) and V6 (415 vs 399 ms, p=0.001). Compared to healthy controls, QT dispersion was slightly larger in the early post-convulsive ECG (36 vs 31 ms, p=0.03). Notched T waves occurred more frequently in the early compared to the late post-convulsive ECGs (p=0.009).
  
  
  CONCLUSIONS
  Slight to moderate post-convulsive prolongation of the QT interval is not rare but transient in paediatric patients.
authors.affiliation: Department of Paediatric Cardiology, Heart Centre Leipzig, and Department of Medicine, University Regensburg, Germany. c.kaendler@t-online.de
authors.forename: Liane
authors.initials: L
authors.lastname: Kändler
authors.forename: Andreas
authors.initials: A
authors.lastname: Fiedler
authors.forename: Katrin
authors.initials: K
authors.lastname: Scheer
authors.forename: Florentine
authors.initials: F
authors.lastname: Wild
authors.forename: Ulrich
authors.initials: U
authors.lastname: Frick
authors.forename: Peter
authors.initials: P
authors.lastname: Schneider
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography; D006339:Heart Rate; D006801:Humans; D007223:Infant; D008133:Long QT Syndrome / Q000175:diagnosis / Q000503:physiopathology*; D011446:Prospective Studies; D012640:Seizures / Q000503:physiopathology*; D013997:Time Factors