The study's findings support a hypothesis first proposed by Dr. Schwartz in 1976 that abnormal development of the nerves controlling the heart's rhythm may predispose some infants to potentially lethal, abnormal heart rhythms during the first year of life. The authors also said that traditional SIDS risk factors such as maternal smoking, bed sharing and sleeping on the abdomen, had markedly lower predictive value than prolonged QT intervals among the infants studied. Until now, there had been little evidence that SIDS is caused by abnormal heart rhythm. Some researchers believe that SIDS may be related to breathing problems, especially long, breathing pauses called apnea. Given their findings, Dr. Schwartz and his colleagues suspect that the risk of SIDS may be decreased by finding prolonged QT intervals on ECGs and using medicines like beta blockers to reduce the likelihood of abnormal heart rhythms.
More research is needed.
The costs, risks and benefits must be weighed before such steps are begun. Screening and treatment questions While infants born into families with a history of prolonged QT intervals are routinely checked for ECG abnormalities during their first month of life, Co-burn J. Porter, M.D., a pediatric cardiologist at Mayo Clinic, says the usefulness of routine ECGs on all newborns is still unclear. Dr. Porter points out that the T-wave measurement is imprecise in the first days and weeks of life. Robert V. Johnson, M.D., a neonatologist and director of Mayo's Newborn Intensive Care Unit, agrees. Using the ECG to predict the risk of SIDS would cause groundless fears for many parents and false reassurance for a few.