A Bristol teenager has become one of the first children in the world to have a pioneering type of heart transplant.
14-year-old Freya Heddington received a so-called 'non beating' heart which, using a special device, was restarted and kept healthy before the operation.
Donated hearts have historically come from people who are brain-dead but whose hearts are still beating, which limits the scope for the number of transplants possible.
But surgeons from the Royal Papworth Hospital in Cambridgeshire have been able to make hearts start beating again after they had stopped, and successfully transplanted them into children.
The doctors have used a heart-in-a-box machine called the Organ Care System to bring the hearts back to life once removed from the donor. The machine replicates the conditions of the human body.
Freya said: "I can do a lot more. I can walk around, I can go out with my friends, I can go up the stairs.
"Things like horse-riding and I don't have to take breathers or I don't have to feel sick or faint."
"It's a difficult thing to process but I try and think of it as I always carry a piece of that person with me, no matter where I go."
The technique had been tried in adults before, but has now saved the lives of six British children aged between 12 and 16 since last February, all of whom had life-threatening conditions.
On average, children have to wait two-and-a-half times longer than adults for hearts to become available.
The breakthrough is expected to allow a substantial expansion in the number of donor hearts available, reduce post-operation complications, speed recoveries, increase transplant survival rates and save hundreds of lives.
Dr John Forsythe, medical director for organ donation and transplantation at NHS Blood and Transplant, said: "This new technique will save lives both here and around the world.
"It means people can donate their hearts where it wouldn't have been possible in the past, giving life to patients on the waiting list."