A family whose two-year-old son received a heart transplant after a 14-month wait in hospital said they have been "given a second chance at life".
Elliot Livingstone, from Hampshire, was diagnosed with dilated cardiomyopathy shortly after his birth in 2013.
He was kept alive by a mechanical heart at Great Ormond Street for 420 days - the longest in the hospital's history.
The toddler returned home earlier this month after having surgery in March.
He was fitted with a "Berlin Heart" - which pumps blood from outside the body - while he waited 420 days in hospital for a donor.
Elliot's parents, Adrian and Candace Livingstone, from Sherfield Park in Basingstoke, said the transplant has given them "a second chance at life" and described the donation as "the most amazing gift ever to be given."
After spending almost half his life on life support, Elliot's parents said they "can't wait to begin enjoying life together as a family".
Mr Livingstone said: "We are enjoying every moment of every single day. Even though he's had a heart transplant and there are certain places we can't go any more, there's still a whole world out there that we can experience."
What is dilated cardiomyopathy?
- Dilated cardiomyopathy is a disease where the walls of the heart become stretched and thin, so they cannot contract properly to pump blood around the body
- Causes include a change or mutation of inherited genes, viral infections, uncontrolled high blood pressure, problems with heart valves, excessive amounts of alcohol, and pregnancy
- Shortness of breath, swelling of the ankles and abdomen, excessive tiredness, and palpitations are all symptoms of the condition
- Treatment: Medicines, a pacemaker, or an implantable cardioverter defibrillator
A senior staff nurse at Great Ormond Street said: "We're all really going to miss Elliot, he is so happy and smiley, he has such an amazing spirit and zest for life, just like his parents."
Mr Livingstone is to run 75 miles from his home to the hospital on Saturday to raise money for the charity.