Prolongation of the QT interval may be congenital, as seen in the Jervell and Lange-Nielsen syndrome (ie, congenitally long QT associated with congenital deafness) and the Romano Ward syndrome (ie, isolated prolongation of QT interval). Both of these syndromes are associated with sudden death due to either primary ventricular fibrillation or torsade that degenerates into ventricular fibrillatio