A bridesmaid has apologized after she collapsed at her sister’s wedding while walking down the aisle.

Carly Williams, 34, was walking alongside her niece at a wedding in Central London. She then went into cardiac arrest and collapsed.

“I’m lucky to be alive, but I feel so guilty about ruining my sister’s big day,” she said. “In all honesty I can’t really remember much at all. The last thing I remember is being on the train in the morning.”

She added, “Literally there’s a massive gap and I remember waking up two days later in hospital and just not having a clue what had happened.”

The bride-to-be, her sister, Jodie, turned around to see what was going on.

“Mum was screaming, ‘Get a defibrillator' and then my cousins came forward.”

When Carly was taken to the hospital, they learned she suffered cardiac arrest. She was placed into a medically induced coma.

Doctors, after giving her an internal defibrillator, said they don’t know the cause of the medical incident.

Jodie had to cancel the wedding to rush to her sister’s side at the hospital.

“We haven’t set another date, but I’m hoping early next year,” she said. “I want to do it before the wedding season starts.”

According to the British Heart Foundation’s Simon Gillespie, “When someone collapses suddenly with cardiac arrest every second counts. CPR can help double chances of survival.”