Patients with deadly heart conditions are mistakenly being diagnosed with stress, research suggests.
An estimated 620,000 people in Britain are living with genetic heart problems, yet the vast majority have no idea they are at risk.
The disorders can go undetected until someone's heart suddenly stops beating.
The British Heart Foundation found six in ten patients with inherited heart conditions had their symptoms attributed to other causes before doctors realised what was wrong with them. Some 23 per cent were told they were suffering with stress or anxiety, 7 per cent were told they had asthma, and 5 per cent epilepsy.
Some 54% had to wait more than two years before they were finally diagnosed with a heart condition, the poll of 370 people with genetic heart conditions revealed.
At least 624 sufferers are thought to die each year from sudden cardiac death, but this figure is considered the tip of the iceberg, with many other deaths mistakenly put down to other causes.
Bolton Wanderers footballer Fabrice Muamba collapsed with such a condition in 2012, aged just 23, his heart stopping for 78 minutes. He recovered and was diagnosed with hypertrophic cardiomyopathy a heart condition caused by genetic factors.
Many inherited heart conditions give people a weak heart muscle, so blood is not pumped properly, while others cause an abnormal heart rhythm, which means the organ could suddenly stop beating.
Miles Frost, son of broadcaster Sir David Frost, collapsed and died at the age of 31 in 2015. A post-mortem examination found he had hypertrophic cardiomyopathy.
Sir David, who had died from a heart attack two years previously, aged 74, had the same condition, but his son was never told he might have inherited the faulty gene and so was never tested for it. Children have a 50 per cent chance of inheriting it.
Dr Mike Knapton, of the British Heart Foundation, said: Inherited heart conditions can be silent killers. This means that early diagnosis is essential so people can be put on the right treatment and live a normal life.'
© Daily Mail