SIDS: Long QT ECG anomaly

Response to Letter Regarding Articles, “Prevalence of Long QT Syndrome Gene Variants in Sudden Infant Death Syndrome,” Peter J. Schwartz, MD Alfred L. George Jr, MD

The letter by Dr O’Rourke does not address correctly the findings and implications of our work on sudden death in infants that began in 1976. ¹ As recently specified elsewhere, ² we have repeatedly proposed a widespread ECG screening in the first month of life with the specific goal of early identification of infants affected by the long QT syndrome (LQTS). We never proposed it with the sole goal of prevention of sudden infant death syndrome, a naïve idea given that sudden infant death syndrome is multifactorial. ³ Our objective has always been the prevention of sudden death caused by LQTS at whatever age it may occur. We and others ^4–7 have progressively demonstrated that a significant percentage of sudden infant death syndrome cases (9.5%; 95% CI, 5.8 to 14.4) are actually caused by LQTS, a highly treatable arrhythmogenic disease of genetic origin. It follows that neonatal ECG screening may allow prevention of these very early LQTS deaths, usually labeled as sudden infant death syndrome.

Contrary to what Dr O’Rourke infers, LQTS deaths are indeed caused by ventricular fibrillation independent of the age of the patients. This is not an assumption. The evidence that lethal arrhythmias underlie LQTS deaths is simply overwhelming. Also contrary to Dr O’Rourke’s statement, we did not “liken [LQTS] to ischemic and other heart diseases”. The rhythm found by the ambulance services, when called for a cardiac arrest, depends on the time elapsed from the onset of the episode, and after several minutes ventricular fibrillation …

http://circ.ahajournals.org/content/116/4/e93.short