Doctors in Australia and New Zealand are starting to unravel the mystery of why apparently healthy young people die unexpectedly.
Two or three such deaths happen each week in the two countries, and many families never find out the reason.
These are young, otherwise healthy, people aged up to 35 with no known life-threatening condition, says University of Sydney professor of medicine Chris Semsarian, who is leading the study.
They are children who go to school and don't come home. People who go to sleep and don't wake up because of sudden cardiac arrest.
So far the world-first study has shown about half the deaths are not explained by an autopsy, said Prof Semsarian, who is presenting a report at a Royal College of Pathologists of Australasia conference in Melbourne on Saturday.
He was assisted by associate professor Jon Skinner, paediatric cardiologist at Starship in Auckland, who said it had been hard to attract funding at the start of research, as sudden cardiac deaths were seen as rare and unpreventable.
The death was bad enough, but for parents not to know what happened led to doubt and suspicion, and a lack of closure.
However, early indications were that about one in three of the unexplained deaths had an underlying genetic heart issue that the family did not know about.
Prof Semsarian said this meant the lives of the person's brothers and sisters could be saved if they had a blood test for the faulty gene.
It was essential for them to speak to their GPs about being tested.
"We have the tools to stop people dying suddenly," he said.
"The challenge is to find out who is at risk."
Preventative measures for people at genetic risk range from advice about avoiding strenuous exercise to medicines such as beta-blockers or implanted devices to keep the heart beating.
Prof Semsarian is also trying to find out if modern technology can provide a viable alternative to physical autopsies, which are discouraged by some religions and many families find traumatic.
"We have found in a pilot study that doing an MRI and CT scan of the body is at least as good as a conventional autopsy at explaining what happened, but it is much less upsetting for the family."
Dr Skinner said there was enough evidence to say any young unexplained death by cardiac arrest should be followed up by cardiac examination of their family.
Up to 30 per cent of the time, it would pick up the problem.
The study hoped to raise that rate towards 50 per cent, provide closure to the families and potentially prevent some sudden deaths.
- with AAP
- Fairfax Media
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