Background: Bradycardia in preterm infants may require anticholinergic therapy (diphemanil methylsulphate). Such treatment may cause prolongation of QT interval and auriculoventricular block.
Case reports: Three premature infants born before 34 weeks of gestational age were given 6-8 mg/kg/d diphemanil because they suffered from bradycardiac episodes. Aggravation and/or persistence of bradycardia required withdrawal of gavage feeding: heart block occurred within a few hours which subsided after cessation of diphemanil and oral refeeding. Diphemanil at progressive dosage was later introduced safely in two of these infants.
Conclusion: The short interval of time between the oral feeding withdrawal and occurrence of heart block justified therapy be stopped or transiently reduced whenever oral feeding must be interrupted.