Syncope in children and adolescents and the congenital long QT syndrome

From a population-based epidemiologic cohort of children and adolescents who sought medical attention for syncope (n = 151), screening 12-lead electrocardiograms were obtained from 118 patients (79 female) to determine the frequency of significant QT prolongation. The distribution of heart rate corrected QT intervals (QTc) was compared with age- and sex-matched controls. Only one patient had QTc >470 ms.