A syndrome previously recognized by Romano and Ward is characterized by prolonged QT interval on the ECG, and spells of unconsciousness. The case of a patient is reported with successive ECG recordings during the attacks; ventricular flutter and multifocal ventricular tachycardia were noted, with rapid spontaneous recovery and relapse. Cases of stillbirth and sudden death in infancy among the siblings, together with QT interval tachycardia were noted, with rapid spontaneous recovery and relapse. Cases of stillbirth and sudden death ininfancy among the siblings, together with QT interval prolongation in the relatives point to an autosomal dominant transmission, with the propositus being apparently homozygous. The chromosomes of the patient are normal. The attacks were controlled by the association of propranolol and digitalis which seems to be the optimal long-term therapy in such cases. In view of the poor prognosis in untreated cases, and the good results of a correct therapy, an ECG should be recorded at rest and after exercise in all children suffering from spells of unconsciousness.