A woman from Cornwall has had life-saving surgery after tests revealed she suffers from a rare life-threatening heart condition.
Becky Lobb, from Carnon Downs, near Truro, spent 20 years being treated for epilepsy, when she had actually had more than 20 cardiac arrests.
She was sent to see a neurologist, who wanted Ms Lobb to undergo an ECG.
As a result, doctors then diagnosed Ms Lobb with the rare condition Long QT Syndrome.
Symptoms typically begin in young children, but may occur in newborns and can appear as late as middle age.
Ms Lobb, aged 37, said: "It's weird. It's great to have a diagnosis but it's also quite scary when they say you're lucky to be alive and you've been cardiac arresting."
A person with Long QT Syndrome suddenly faints or passes out during exercise, or when experiencing intense emotions, such as fear.
It can also occur during sleep or arousal from sleep.
Ms Lobb added: "They are horrendous. I can say I do feel like I am dying.
"They are like normal dreams which are interrupted by loud noises. It's a complete and utter muddle. I slowly come back to consciousness. Afterwards I don't know who I am, or where I am. It is really scary."
There is usually no warning, or sensation of feeling faint or dizzy beforehand.
In one in three cases where death results, the person appears quite fit and healthy, with no symptoms at all before cardiac arrest.
Ms Lobb has now had a pacemaker fitted and takes medication.
She said: "Day to day my life is pretty much back to normal. Hopefully with the defibrillator, pacemaker and beta blockers, I shouldn't have to go through that ever again.
"I still have the fear, but I hope in time they will become a distant memory."