Warning signs of a heart condition which can quickly turn deadly could now be spotted in living patients for the first time.
Scientists have worked out how to use a brain scanner to diagnose people with hypertrophic cardiomyopathy.
The condition can go unnoticed forever in some people – as many as one in 500 are believed to have it worldwide – but cause sudden death in others.
Bolton Wanderers footballer Fabrice Muamba famously collapsed on the pitch during a game in 2012 because of the condition, despite only being 23 years old.
And, until now, it could not be diagnosed in living patients because it requires close examination of the fibres in the heart.
Scientists can use MRI scanners to take pictures of the heart muscle fibres and spot signs of deadly hypertrophic cardiomyopathy. This scan, taken during the research, shows a normal heart structure on the left and, on the right, a heart with muscle fibre disarray which is shown by the yellow ring of muscle fibres being broken up and incomplete
Researchers at Oxford University have used brain scanning technology to spot ‘disarray’ in muscle fibres in the heart which are a tell-tale sign of the condition.
Heart fibres in patients with hypertrophic cardiomyopathy aren’t arranged in the same way as in a healthy patient, and are less able to spread a heartbeat evenly across the organ.
This means certain parts of the heart become abnormally thick, raising the risk of an irregular heartbeat, heart failure, stroke or sudden death by cardiac arrest.
In the past, studying these heart fibres to check for abnormalities could only be done after a patient had already died.
Being able to do it while someone is still alive and potentially healthy could offer doctors opportunities to protect people from heart damage.
‘This is the first time that we’ve been able to assess disarray non-invasively in living patients with hypertrophic cardiomyopathy,’ said Dr Rina Ariga, an NHS cardiologist and a lead author of the study.
‘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.’
If the scan reveals someone has the tell-tale disarray in their heart muscle fibres, doctors could put in a defibrillator.
This would be an electronic device which, when it detects the heart is not beating normally, kick-starts the organ to resume a normal heartbeat.
Although many patients live full, long lives without ever knowing they have the condition, hypertrophic cardiomyopathy is the top heart-related cause of sudden deaths among young people, according to Dr Ariga.
Muamba was just 23 when he collapsed because of the condition 41 minutes into an FA Cup quarter-final match against Tottenham Hotspur.
Medics gave him CPR on the field and he needed 15 defibrillator shocks, two of them given on the pitch, to revive him after he ‘died’ for 78 minutes.
Fabrice Muamba (pictured) was playing in an FA Cup match for Bolton Wanderers when his heart suddenly stopped because of hypertrophic cardiomyopathy
Players and fans looked on as medics desperately tried to revive Muamba by performing CPR on the pitch after he collapsed during the game – he ‘died’ for more than an hour but was successfully resuscitated
WHAT IS HYPERTROPHIC CARDIOMYOPATHY?
Hypertrophic cardiomyopathy is a condition where the heart muscle becomes thickened.
Around one in 5,000 people have the condition, and it most commonly develops during the teenage years or young adulthood.
However, the symptoms vary depending on the severity.
These include shortness of breath, chest pain, palpitations, dizziness and fainting attacks – most commonly during exercise.
It can cause the heart muscle to become stiff, which means your left ventricle doesn’t fill as easily as normal and less blood is then pumped out.
It can also partially obstruct blood flow, which can make small blood clots more likely.
The now-recovered and retired player said afterwards: ‘The last thing I remember was [a defender] screaming at me to get back and help out in defence.
‘I just felt myself falling then I felt two thumps as my head hit the ground in front of me then that was it. Blackness, nothing. I was dead.’
The researchers’ pioneering technique involves using an MRI machine, which are used by the NHS every day to scan various parts of the body.
Although successful at scanning the brain, scientists had found it harder to make the technique work on the constantly-moving heart.
But by always scanning when the heart was most relaxed, they have been able to piece together images of how the heart’s fibres are arranged.
‘The problem is that the large movements of a beating heart dwarf the microscopic diffusional motion of the water molecules that we are trying to measure,’ said Dr Liz Tunnicliffe, a co-author of the study.
‘Recent advances in magnetic resonance technology have now made diffusion tensor imaging of the heart feasible in humans.’
Professor Metin Avkiran, associate medical director at the British Heart Foundation, which helped fund the research, added: ‘Every week in the UK, 12 people under the age of 35 die following sudden cardiac arrest.
‘Many of these deaths are due to inherited heart conditions, of which hypertrophic cardiomyopathy (HCM) is the most common.
‘This exciting research opens up the possibility of using a non-invasive scan to better spot heart muscle changes in people with HCM, find those at risk of a sudden cardiac arrest and ensure they receive the best preventative care.
‘Although further work is needed to refine and test this scan, its potential benefit to patients with HCM is huge.
‘This work is an excellent example of cutting-edge, research-led technology that could change the way we diagnose and treat heart and circulatory diseases.’
The research was published in the Journal of the American College of Cardiology.