Polymorphous ventricular tachycardia in a newborn with the long QT interval.

We have reported a case of long QT syndrome in a neonate who had ventricular tachycardia 30 minutes after birth. On the third day, while being weaned from lidocaine, the patient had ventricular flutter and required cardioversion. Treatment with propranolol (5 mg/kg/day) maintained normal sinus rhythm. We believe this may be the first reported case of long QT syndrome and normal AV conduction in a neonate who had multiple episodes of ventricular tachycardia despite medical treatment.