A mother who believes her daughter died of a rare heart condition after being startled by her alarm clock is calling for a fresh inquest into her death.
Lisa Browne's mother believes her daughter had Long QT Syndrome
Doreen Harley, from Connah's Quay, said she has medical proof her daughter, Lisa Browne, 27, who nursed in Chester, died of Long QT Syndrome.
The inquest into the nurse's death in 1998 recorded an open verdict and with an unascertainable cause of death.
Mrs Harley described the new evidence as "the end of the nightmare".
She said: "It's something we have always wanted. The family could just not accept that Lisa died for no apparent reason."
Mrs Harley, of Connah's Quay, Flintshire, turned to experts in Sweden for the technology to conduct genetic tests on post-mortem tissue taken from her daughter, who worked at the Countess of Chester Hospital.
DNA experts confirmed that Lisa, who was found dead in bed with her arm resting on the alarm clock, had Long QT Syndrome, an hereditary electrical abnormality of the heart.
Doreen Harley said she was optimistic the inquest would be reopened
Members of Mrs Harley's family have since been found to have the condition which can cause loss of consciousness and sudden death.
As a result, said Mrs Harley, her surviving daughter, Rachel, was fitted with a small internal defibrillator three years ago.
She said: "Just weeks after she'd had it done, her youngest son woke up screaming one night and Rachel blacked out and the little machine kick started her heart.
"If she'd not had that surgery she'd not be here today.
"The defective gene is carried in the family. The trigger for death is sudden noise."
Mrs Harley, who also wants a UK-wide cardiac screening programme, said she had been in touch with the coroner over her findings and was "extremely optimistic" about having a new inquest.
She said: "I think it won't be long now before we get the inquest reopened and I feel very hopeful that the cause of death will be put down as Long QT Syndrome."
Long QT Syndrome affects the length of time it takes the heart's electrical system to recharge following a heartbeat - known as the QT interval.
People who have a Long QT interval are vulnerable to a fast, abnormal heart rhythm.
When this occurs, no blood is pumped out of the heart and the brain becomes deprived of blood, causing loss of consciousness and sudden death.
Those at risk can be treated either with drugs or with an implantable defibrillator which will shock the heart into action during cardiac arrest.