The perinatal manifestations of the long QT syndrome are rare, but early diagnosis and therapy are necessary to prevent sudden death.
Case reports: A long QT syndrome was diagnosed in two neonates who presented with foetal bradycardia. In one case, a mutation in the gene KCNQ1 was identified, and a long QT syndrome was diagnosed in the mother and two brothers of the neonate. On beta-blocker therapy, one infant became free of long QT syndrome related symptoms, but a sudden death of the second infant occurred.
Conclusion: The long QT syndrome should be considered in the differential diagnosis of foetal bradycardia. Early treatment of the neonate and his family may prevent ventricular arrhythmias and sudden death.