A St Albans runner, whose 'miracle' son underwent surgery on his heart, is taking part in the London Marathon virtually to raise money for charity.

Dave Oh is taking on the challenge of running the virtual marathon in aid of Kawasaki Disease – the leading cause of acquired heart disease in children in the UK.

Mr Oh's son, Jayden, became the first child in Hong Kong to ever undergo a triple heart bypass at just five-years-old.

Shortly after his birth, Jayden developed two giant aneurysms in his coronary arteries, but his left coronary artery had narrowed, and his right coronary artery was blocked completely.

Jayden spent two months in hospital before coming home and despite his ordeal and having to live with acquired heart disease, he was an active child, his father said.

He loved playing football, scooting, swimming, and fighting with his little brother.

But in June 2013, Jayden suffered severe heart failure and his parents, Dave and Meko, were told his best chance of survival was to undergo a coronary artery bypass graft.

Jayden went through 10 hours of surgery, and spent a further 12 days in intensive care, where he was hooked up with a mechanical pump because his heart was not strong enough to function on its own.

Mr Oh recalled: "It was the toughest time of our lives. We were lingering around the ICU everyday praying for his heart to resume. After a week of ups and downs, his heart was working again."

A few weeks after surgery, Jayden’s doctors discussed the necessity of a heart transplant as the improvement of his heart function was slow - but miraculously his condition improved and a transplant was not deemed necessary.

Now aged 13, Jayden is living a relatively normal life, although he still attends check-ups at Great Ormond Street Hospital, where he has received care since 2014, and he will require medication for the rest of his life.

Mr Oh said: "Jayden has shown such courage over the years despite the constant hospital visits, daily anti heart failure medication and uncertainty. He has overcome so many obstacles and endured more pain than many will have to in a lifetime – he is and always will be our miracle boy."

Dave Oh will be taking part in the virtual London Marathon

Dave Oh will be taking part in the virtual London Marathon

Jayden's parents have dedicated their life to raising awareness of Kawasaki Disease so other children don’t have to go through what their son did.

Running the London marathon has always been on Mr Oh's bucket list of things to do and as well as raising money and awareness of Kawasaki Disease for Societi Foundation he will also be raising money for Great Ormond Street Hospital.

Rachael McCormack, founder of Societi said: "We are beyond grateful to Dave and all his incredibly generous friends and family – who have donated to Societi Foundation. Charities are facing the toughest of times just now with so much of our usual fundraising stopped or delayed.

"Societi relies solely on donations to continue its vital work - to protect children’s hearts this. Their generous donations really will help to protect tiny hearts."