Joanne went to sleep that night five years ago and never woke up. The full-of-life primary school teacher was the latest, shocking victim of sudden death syndrome.

It affects up to eight young people in the UK each week – another victim was Daniel Yorath, brother of ITV’s sports presenter Gabby Logan.

Now a pioneering scheme with hundreds of volunteers being screened for signs of the potentially lethal cardiac conditions is underway – thanks to a charity and the unstinting efforts of Joanne’s parents, Alex and Fraser Fotheringham.

"It was April 5, 1997, and Joanne left our home in Ullapool to travel to Glasgow," Alex recalled. "It was just a normal morning. How could you ever imagine that your daughter wasn’t coming home again?

"The first we knew something was wrong was when a policeman came to the house the following morning to tell us Joanne had died during the night.

"We just couldn’t take it in. Even when the post mortem took place, we were told the cause of death was unascertainable, as there was nothing to see.

"We simply couldn’t accept that a normal, happy, healthy girl could go to bed one night and not wake up.

"It seemed to have been a real million to one thing, and over and over again we’d ask ourselves what went wrong."

Eventually the couple were put in touch with Cardiac Risk in the Young (CRY), a charity which offers counselling and support, and also campaigned for cardiac testing of young people for hidden heart defects.

It was through them that the couple learned of the condition, which so tragically claimed Joanne’s life.

"We had felt that we were alone", explained Alex. "We had no idea that so many other families lives were ruined in this way.

"Though we didn’t know it, Joanne’s condition had been a walking time bomb with this waiting to happen."

Sudden death syndrome is an umbrella term covering the different causes of unexplained cardiac arrest in the young. They include thickening of the heart muscle and irregularities of the electrical impulses that control the heart’s rhythm.

Early detection allows treatment either by medication, fitting a pacemaker or by using an ICD, which sends an electrical shock into the heart to restore normal rhythms.

Since Joanne’s death, Alex and Fraser have campaigned for ECG heart tests to spot the problem before it is too late.

Now, they’ve finally succeeded. Until the end of this month, the UK’s first ethically approved ECG testing pilot scheme will run in and around the Isle of Lewis.

"This first screening programme comes at a time when cardiac abnormalities can be treated effectively," said Tom Storey of the Medical Technology Group, which promotes access to technological treatments and of which CRY is a member.

"Let’s hope many lives are saved by this and it’s repeated across the rest of Britain."

That’s a hope shared by Alex and Fraser.

"We wont be told the name of anyone who has an abnormality detected," added Alex, "Their privacy will be protected.

" As far as we’re concerned, if just one other family is spared the living nightmare that we have had to go through, the it will have been worthwhile.

If Joanne had been screened, she could still be alive, but we can’t be bitter.

"In many ways, keeping this going has been difficult, with all the memories. But Joanne was the sort of person who would have done this for someone else, so we feel we just have to do this for her.