Isaac was told that he had inherited a dangerous heart condition from his dad. He came to Great Ormond Street Hospital (GOSH) for surgery, watch his video podcast to find out more.
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My heart condition
"As my dad had a heart condition called hypertrophic cardiomyopathy and it is hereditary, I had to be checked regularly. Earlier in the year, they found that I had it too.
"I had more tests to see how serious it was because there are five different stages. One is the easiest to deal with using tablets. Number five is trouble. I was at the maximum – number five.
"I went to GOSH for a consultation. They told me I would need a defibrillator fitting. When you exercise your heart rate goes up but mine does that randomly and sometimes it can be dangerous. If the defibrillator detects that my heart is going above 240 beats a minute it gives me a shock which brings my heart back to a normal level. It does the same thing if my heart goes too slowly.
"We came back from holiday three days before the operation. I think that was better because my mind was not on it when I was away.
"On the day, they gave me a general anaesthetic and the operation was two-and-bit hours long. They pulled my muscle forward and put the defibrillator under my muscle. Wires go from it straight into my heart. It left quite a neat little scar, which is not too bad.
"They also had to stop my heart to make sure the thing worked. Then they put it in a fast episode to make sure it slowed down after the shock. Within eight hours I was up and about and I went home the next day.
"I was not allowed to exercise for two months after and I had to give up rugby, which I used to play six times a week. But now I coach my brother’s team and I play water polo.
"I think what they did was amazing and I’d just like to say thanks because everyone has been so supportive.
"Being in the film was annoying when they wanted to talk to me two hours after the operation but I am glad I did it. When I was there they did not explain what would happen on the day. But my video will cover that. It means I can help someone else."
Courtesy of BBC Newsround