Study Shows Some Crib Deaths Are Heart-Related
About 3,000 infants die each year in the United States alone of SIDS, defined as the sudden and unexplained death of an infant less than 1 year old. Previous research has also suggested sleeping on the stomach, nervous system problems related to breathing, abnormal metabolism in the liver and flaws in the heart's electrical channels could be among the causes, Reuters reported.
The American Academy of Pediatrics recommends infants be placed on their backs to sleep instead of on their stomachs, and studies have indicated that change has reduced the incidence of SIDS.
The study released Tuesday at the American Heart Association meeting in Chicago found that in one out of 20 cases of SIDS, the baby has a problem similar to a heart condition called long Q-T syndrome that sometimes causes sudden death in young people and adults.
With long Q-T syndrome, the heart electrically recharges itself too slowly or in a disorganized way, ahead of the next heartbeat, and can sometimes cause the heart to stop pumping.
An estimated one in 5,000 people may suffer from the syndrome.
The researchers, led by Michael Ackerman, an assistant professor at the Mayo Clinic, performed a genetic autopsy on every unexplained infant death investigated in Arkansas from September 1997 to August 1999. There were 93 cases. "Long Q-T syndrome is sometimes called the perfect killer, because it leaves no clues," Ackerman said in a news release issued by the Heart Association. "Neither does SIDS." "SIDS will probably turn out to have 20 different underlying causes," he added. "If we can figure out what they are, we can screen for them and hopefully one day, prevent future cases."
Ackerman urged medical examiners to collect and store tissue in sudden infant deaths in a way that allows researchers to carry out a molecular autopsy, in order to continue to study the possible causes of SIDS.