The study published in Heart -the subsidiary publication of the British Medical Journal shows that around 500 people may die every year from sudden arrhythmic death syndrome (SADS). It could also be attributable to a genetic heart defect.
SADS is characterized by severe abnormalities in heart rhythm, with the syndrome carried by a genetic heart defect.
The previous studies had found that 0.16 deaths for every 100,000 were attributable to SADS, but now scientists say that the proportion is 1.34 per 100,000.
However, the scientists reached to the recent conclusion by examining and analyzing unexplained death judgments from 117 of the nation's 122 coroners between October 1997 and May 1999.
The study suggests that SADS is linked to a genetic heart defect and family members should be screened to prevent more deaths. It also revealed that only one-third of cases had been correctly identified by autopsy.
Moreover, when all the unexplained causes of death in national records that might have actually been SADS, were added, the experts found a marked difference that suggested that the rate could be as high as 1.34 per 100,000 - up to eight times higher than they had estimated and equating to 500 deaths per year.
The researchers feel that under-reporting to of SADS could be attributed to deaths being misclassified or families not agreeing to further expert cardiac examination.
Some of the deaths in the study were attributed to heart attack or other causes, such as epilepsy and drowning.
Ellen Mason, a British Heart Foundation heart nurse told BBC, "Clearer ways to identify possible victims of SADS are vital."
"If a person dies from SADS, specialist centers can offer genetic screening to their bereaved families. Monitoring people who could be at risk of SADS and giving them specialist treatment may prevent further tragic deaths," she added.
