Newborn electrocardiography as a screening method for long-QT syndrome

Abstract

Prolongation of the QT interval is the cause of about 10% cases of sudden infant death syndrome (SIDS) innewborns but it is also responsible for about 5% of sudden deaths in adults. LQTS is associated with life threateningarrhythmias such us torsade de pointes ventricular tachycardia or ventricular fibrillation (VF) leading to suddendeath.Congenital causes (channelopathies) of LQTS are associated to mutations with different hereditary patternaccording affected gene but it has been proven that several drugs and electrolytic alterations can significantlyincrease the QT interval. However, the cost-effectiveness of neonatal electrocardiographic (EKG) screening hasbeen questioned and despite studies made in newborns there is still no consensus about the best moment to makeand electrocardiographic screening.Previous studies demonstrate that newborns with QTc values over 470 msec often normalize by themselves inthe first month of life. However in some cases these values remain high after first months of life. These cases aremore frequently in determinate ethnics (Maghreb, Morocco and India-Pakistan). These races could be linked tocardiac electrical alterations with a hereditary pattern of variable penetrance. An EKG performed in the first month oflife will allow the early identification of still asymptomatic infants with LQTS and also infants with some correctablecongenital heart defects (CHD) not recognized by routine neonatal examinations. Appropriate therapy will preventunnecessary deaths in infants, children, and young adults. At the light of this literature review we could assess thatneonatal electrocardiographic screening is highly cost-effective and it may permit the early identification of infants atrisk for SIDS.