The first surgery on her heart took place when she was just two days old, and she has gone under the knife more than a dozen times since then.

Teenager Katie MacRae's life has been one of doctors appointments, hospital beds and medical procedures after she was born with the arteries of her heart back-to-front.

Yet despite facing more ordeals in her 15 years on earth than most people face in a lifetime, the youngster hasn't let her condition slow her down and has just scaled Ben Nevis to raise money for other children facing heart surgery.

The Herald:

Katie during the Ben Nevis climb

The schoolgirl, from Inverness, was born with the main arteries in her heart swapped round, stopping oxygenated blood from circulating her body.

She also suffered from a narrowing of the pulmonary valve, and a large hole was also found in the side of the organ.

READ MORE: Experts says Ben Nevis has 'grown a metre'.

Despite the grim prognosis, she battled back from the brink of death as a baby, and now lives with a “hammock” made from raincoat material, a pig’s valve and three metal stents in her heart to keep it beating.

And, this summer, she defied everyone - including herself - to reach the summit of Scotland's highest mountain in just five hours, raising almost £2,000 to help other young people.

Miss MacRae, who made the 4,413ft ascent with her uncle, Rory MacLeod, said: “When I told my granny and grandad I was going to do it, they thought I was joking.

“I didn’t really think I would be able to do it. It was exhausting. But when I got to the top it was just amazing. I was quite surprised that I made it.

“I had to stop about 10 minutes from the top because it got really steep and my feet were killing me. But I was with my uncle and he was good motivation for me.

“It was so foggy, you couldn’t really see in front of you. It seemed to go on forever, but when we got to the top, I was like, ‘yes, finally’.

“It felt really good.”

The Herald:

Katie's heart defects were discovered when she was just days old 

Doctors first discovered problems with the teenager's heart while her mother, Tina, was still in the neonatal ward at the Raigmore |Hospital in Inverness.

At two days old she was airlifted from Inverness to Glasgow for a life-saving operation to keep a valve that naturally closes soon after birth open. Without it, she would have died.

Surgeons then inserted a shunt in her heart at six weeks old, to improve the flow of blood to the lungs and boost her oxygen levels.

READ MORE: Breathtaking aerial video of Ben Nevis using camera drone

But soon after she was struck down with hospital super-bug rotavirus and left clinging to life in intensive care three times over the next six weeks.

Despite her heart only being the size of a strawberry and her surgeon being over 6ft tall, however, his life-saving skills gave Katie time to grow until she could have open heart surgery at three years old.

She was just three months off her fourth birthday when surgeons rewired her back-to-front heart by sewing in a “Gore-tex hammock” to help it work efficiently.

The Herald:

Ben Nevis (Stock photo)

Her mother said: “The valves in her heart are still back to front. If she had transposition of the great arteries they would have just switched them round but because the valve was also narrower they just had to make-do with what was there. They just changed and added to it.”

Rmarkably after all she has been through, the one thing that the teenager, who also had a metal stent inserted in her heart when she was five, fears most about surgery is the needles.

She said: “I hate needles so much. I’ve got a heart condition so having a fear of needles is not the best. For my last surgery when I was 13 I asked for the mask to go to sleep.”

As she is susceptible to infection, she has to consult with her cardiologist on everything from dental treatment to if she wanted her ears pierced. So before she could scale Ben Nevis she needed the go-head from them.

READ MORE: Father planning to climb height of Everest for charity in memory of his son​.

She said: “They said there was nothing to stop me doing it, as long as I didn’t do it straight away and climbed a few hills before.”

She started with a 1,470ft hike up East Lomond in Fife, before moving on to scale the Law, Clackmannanshire, at 2,093ft and then the adjoining Ben Cleuch, which is 2,365ft, before finally making it to the summit of Britain’s highest peak.

The Herald:

Katie has now raised more than £1,800 in aid of the Zak Scott Braveheart Foundation, which was set up in memory of the 14-year-old who died following complications after heart surgery.

The charity grants small wishes to children having heart operations at the Royal Hospital for Children in Glasgow and following her last surgery she received a special bracelet with an “open your heart” charm.

She said: “The Zak Scott Foundation has helped me and many other kids and I wanted to give something back.”

The teenager also hopes to go on to become a play nurse in a children’s hospital after being inspired by the one who helped her during her time in hospital in 2016.