Relatives of people who die from sudden death syndrome should be screened for hidden heart problems, say experts.
Many of the 12 unexplained deaths a day among young people in the UK are found subsequently to be the result of inherited heart conditions.
The British Heart Foundation (BHF) says a simple blood test can establish whether blood relatives carry the same genetic risk.
It is urging more people to have the tests.
Guidelines are being issued to all coroners in England and Wales, asking them to promote screening, as they are often the first point of contact after post-death investigations.
Inherited heart conditions, such as Long QT Syndrome, can be picked up by a simple trace, known as an ECG, that looks at the electrical activity within the heart.
Screening widely available
But currently not everyone who is at risk gets tested.
Doctors may also want to do a type of scan called an echocardiogram to examine the heart’s appearance.
The BHF says hundreds of lives could be saved by better uptake of the screening, which is on offer to any relatives who have lost a loved one because of an inherited heart condition.
Testing will mean some can be reassured that they do not carry the same risk, and those found to have inherited culprit genes can take action to lower their own heart risk – for example, by changing their lifestyle.
Prof Peter Weissberg, medical director at the BHF, said: “The death of a loved one can, sadly, be the first time people find out about an inherited heart condition in their family.
“Yet even after a ‘suspicious’ death, family members are not always screened themselves. Their life could be in danger and their family could be devastated all over again – something a simple blood test could set right.”