[Genetic testing in hereditary arrythmia syndromes today and in the future]

Electrocardiographic Screening in the First Days of Life for Diagnosing Long QT Syndrome: Findings from a Birth Cohort Study in Germany

INTRODUCTION

Newborn sudden infant death syndrome (SIDS) has failed to decrease in the last decades, and a third of the neonatal cases occurred within the first 6 days of life. The long QT syndrome (LQTS) is a genetic disease with a prevalence of 1 in 2,000 live births and contributes to almost 10% of SIDS cases. Early identification of LQTS through electrocardiogram (ECG) screening is likely to reduce mortality.

METHODS AND RESULTS

In this ongoing prospective study we evaluated 2,251 ECGs from newborns participating in the KUNO Kids birth cohort study between July 2015 and July 2018. ECGs were recorded at a mean age of 2.0 days (IQR 0 days). The QT interval was corrected for heart rate using Bazett's formula (QTc). A QTc between 451 and 460, 461-470, and >470 ms was measured in 23 (1.0), 14 (0.6), and 62 (2.8%) participants, respectively. Fourteen neonates (0.62%) were admitted and monitored because their initial QTc was ≥500 ms. In 2 genetically analyzed participants, a mutation was found. One disease-causing for LQTS type 1 and the other of unclear significance. Cascade screening revealed affected members in both families.

CONCLUSION

A standardized neonatal ECG screening in the first days of life is able to identify neonates with a relevant transient form of prolonged QT intervals and to aid diagnosing congenital LQTS.