The number of adults who suddenly die without explanation could be much higher than recorded in official figures, researchers said today.
A study funded by the British Heart Foundation estimated that 3,500 apparently healthy adults die suddenly each year in England.
It found that in around four per cent of such deaths no cause can be found – despite a full postmortem examination.
However as there is no recognised category for recording such deaths, it is difficult to obtain a clear picture of the exact number of victims.
Lead researcher Dr Tim Bowker, associate medical director at the BHF, said: “It has long been recognised that there are occasions when an apparently previously healthy adult dies suddenly and unexpectedly and any abnormalities found at postmortem are minimal or nonexistent.
“In such cases it can be very difficult to identify a precise cause of death. This leads us to question whether these deaths are rare or represent the tip of a larger iceberg.”
He said such deaths should be classed as the adult equivalent of the Sudden Infant Death Syndrome (SIDS). Giving the condition a name, Sudden Adult Death Syndrome (SADS), would lead to greater understanding of the scale of the problem.
The study, in the Quarterly Journal of Medicine, took a sample of 67 coroners across England. The research team from the National Heart and Lung Institute in London looked at people who died suddenly aged between 16 and 64 years.
All had no previously documented heart disease but were found during a postmortem to have cardiac cause or no identifiable cause of death.
It is thought that many sudden adult deaths are due to electrical abnormalities, some of which are inherited.
However electrical measurements of the heart can only be made when the person is alive.
Professor Sir Charles George, medical director of the BHF said: “This study takes us another step closer to unravelling the mystery that surrounds the tragedy of healthy adults dying prematurely from sudden adult death.”
He said at this stage there was not enough evidence to call for population screening.
Read more: Sudden death mystery of ‘healthy people’