A genetic flaw can cause heart muscle to thicken
By Adam Brimelow Health Correspondent, BBC News
The Bolton footballer Fabrice Muamba has said his survival from sudden cardiac arrest was “more than a miracle”, but his case has highlighted the limitations of screening for hidden heart problems. He was examined several times but nothing was picked up.
I have been looking at efforts to detect these abnormalities, which kill 12 young people in the UK every week.
When you see Rishi Chandarana charging around his garden in his beloved Arsenal shirt, he seems like any sports-mad 12 year-old, straining every sinew to be first to the ball.
But his father and grandfather both have a condition called Hypertrophic Cardiomyopathy (HCM). This inherited genetic flaw causes the heart muscle to thicken, interfering with its ability to beat.
The condition affects one in 500 people. Some never have any symptoms. Others develop chest pain, dizziness or palpitations which can be treated.
But some – a small minority – suffer cardiac arrest without warning. HCM is the biggest cause of sudden death in young people.
When I first met Rishi he had been for some initial tests at a new clinic for inherited cardiac conditions at London’s Royal Brompton Hospital. He was concerned that if he had HCM, it could affect his enjoyment of sports.
“If I’m not able to play football it will be devastating because I really love playing sport. And if I can’t play sport because of a heart condition, I’d be really upset.”
The clinic sees people of all ages from across the UK – some with a suspected risk because of problems in the family, and some to assess and manage conditions such as HCM.
Many of the tests carried out are similar to those used routinely at other screening centres, including an electrocardiogram (ECG) and echocardiogram.
Scarring in the heart
But the Royal Brompton team also use MRI scans and genetic testing to provide more detailed information. The cardiologist in charge, Dr Sanjay Prasad says this approach is unique.
“Over and above other tests it gives you an idea of what’s happening at the tissue level. Is there scarring in the heart? Is there inflammation?”
He says the genetic tests they offer address not just ‘what is happening’ but ‘why?’
“Because it is a familial condition often patients suffer the dilemma of not knowing whether their offspring have the condition. And the genetics allows us to take things to a higher level where we can reassure patients that if they haven’t got the gene abnormality, they should be leading a normal lifestyle.”
Dr Prasad says a biobank of DNA samples collected at the clinic will – over time – provide a better understanding of who is most at risk.
“I think that’s hugely exciting and that programme is certainly a very welcome development, but I have to say at the moment it’s still research.””
Dr Amanda Varnava Consultant Cardiologist
The clinic has won praise from another leading specialist in this field, Dr Amanda Varnava, from St Mary’s hospital in London. But she says the value of genetic testing remains limited, at least for the time being.
“I think that’s hugely exciting and that programme is certainly a very welcome development, but I have to say at the moment it’s still research.”
Dr Varnava also carries out cardiac checks on players for several premiership football clubs. She says the game’s authorities should consider a more systematic and rigorous approach to screening.
“What we’re not doing is further testing such as exercise testing, looking at the ECG under stress. And we’re not looking at the heart monitor over 24-hours to see if we can pick up any extra beats that may give us a clue to future problems. Those are the additional tests perhaps we should be thinking about”
For the wider population the charity Cardiac Risk in the Young (CRY) says the immediate priority must be an extension of basic screening. This would focus on family history, a physical examination and an ECG – followed up if necessary by ultrasound.
Protection from “catastrophe”
A cardiology consultant for CRY, professor Sanjay Sharma, says the charity has been inundated with requests for screening in the last few weeks.
“What we’re saying is that there should be an infrastructure that’s available, that people know about, and they can go and seek help or tests in this area so that they are well-informed and can protect themselves from catastrophe.
He says this should be offered to all 14-35 year-olds, and he points to the success of wider screening in Italy, where he says sudden cardiac deaths have fallen by 90% in 25 years.
The Department of Health in England says it is keeping this issue under review.
Back at the Royal Brompton clinic I joined Rishi as he was told that tests so far indicated he did not have HCM. Dr Prasad told him to carry on playing football, “as long as it’s not for Arsenal!”