A new scan technique could identify people at risk of collapsing and dying suddenly from a hidden heart condition - hypertrophic cardiomyopathy.
The condition is the top cause of sudden cardiac death in young people, BBC reports.
Results from the study were published in the Journal of the American College of Cardiology,
In people with hypertrophic cardiomyopathy, signs of structural changes in the heart can only be picked up after death.
But University of Oxford researchers used microscopic imaging to spot the same patterns in living patients.
The research team focused on detecting those at risk of sudden death, by looking for abnormal fibre patterns in the heart which could lead to potentially deadly heart rhythms. They can then have a small device implanted in their heart to kick-start it into beating again when abnormal heart rhythm is detected.
We're hopeful that this new scan will improve the way we identify high-risk patients, so that they can receive an implantable cardioverter defibrillator early to prevent sudden death"q comments Dr Rina Ariga, study author and cardiologist at University of Oxford.
Calculating a patient's risk currently is based on the thickness of their heart wall, their family history, plus any unexplained collapses and abnormal heart rhythms.
On the other hand, the Oxford researchers' approach is that they used MRI scans to look at detailed images of the structure of the heart muscle to check for "muscle fibre disarray".
This suggests that heartbeats are not allowed to spread evenly across the heart's muscle fibres.
The technique, called diffusion tensor magnetic resonance imaging, is normally used on the brain - but advances mean it can now be used on the heart.