The QT interval during exercise in healthy children 6-14 years old

Some children and adolescents with stress-induced syncope and a normal QT interval at rest are said to have a prolonged QT interval during exercise. Normal values for the QT interval of children during exercise, however, are lacking. Therefore, the authors determined, in 60 healthy boys aged 6-14 years, the QT interval during stepwise increase in exercise on a bicycle ergometer and constructed a graph containing, with a probability of 95%, at least 90% of normal QT intervals during exercise within its confidence limits. The QT interval as a function of heart rate during exercise can be expressed by the equation QT (s) = 0.4 - 9.18.10(-4) x heart rate (min-1) +/- 0.02.