Babies who die from sudden infant death syndrome (SIDS) are more likely to have abnormal heartbeats few days after birth, according to a study tomorrow New England Journal of Medicine . If the finding is confirmed by other studies, it may help doctors identify high-risk babies and could lead to drug treatments that prevent some SIDS deaths.
When a child younger than 1 year dies suddenly of unexplained causes, doctors typically exclude SIDS as the cause of death. The researchers suspect that several abnormalities contribute to the deaths of SIDS, including difficulty breathing, gastrointestinal diseases and metabolic disorders. There are more than 20 years, several cardiologists, including Peter Schwartz of the Policlinico San Matteo in Pavia, Italy, suggested that babies with a long so-called QT interval in an electrical recording of their heartbeat may be more at risk SIDS. The measurements of the QT interval about the time it takes the heart muscle to recover after receiving an electrical signal to contract. If some heart tissue plates take longer to recover than others, they can beat out of sync, and lead to sudden death. The long QT syndrome, often caused by genetic defects, is a leading cause of sudden death in children and young adults.
Schwartz and his colleagues began a long-term study in 1976, recording electrocardiograms babies apparently healthy three or four days after birth. After 19 years, they had data on more than 34,000 children. Of the 33,034 they were able to follow through their first birthday, 34 had died, with 24 deaths attributed to SIDS. Of the 24, half had abnormally long QT intervals; none of the 10 who died of other causes had this problem. This suggests, the authors write, that detectable cardiac abnormalities in the first week of life may be responsible for a significant percentage of SIDS deaths.
Some experts are not convinced. While Schwartz team was collecting its data, other scientists have published several studies reporting no evidence of long QT intervals in groups of infants at high risk - the siblings of SIDS victims and babies who survived close calls. And another study of more than 7,000 babies randomly selected electrocardiograms revealed that 15 died of SIDS were not significantly different from those of healthy babies.
But if Schwartz's findings are replicated, they could be put to good use: Older children with long QT syndrome are usually treated with beta-blockers medicines called that help smooth the heart rhythms irregular. If the long QT interval is a risk factor, said Richard Friedman pediatric cardiologist at Baylor College of Medicine in Houston, some cases of SIDS "may be a preventable type of thing."
0 Komentar