A Nottinghamshire teenager, Flynn, 17, suffered significant brain damage after his heart stopped for 15 minutes, according to his mother, Melanie. She found him collapsed on his bedroom floor in the early hours of 2 April.
Flynn's heart stopped due to a fault causing incorrect signals, leading to his brain being starved of oxygen. This resulted in him being unable to walk and affecting his sight, with doctors stating he might never fully recover.
He has since undergone a procedure to correct the heart problem and had an implanted defibrillator fitted. Flynn is now undergoing rehabilitation at Nottingham City Hospital, with therapists describing his progress as "remarkable".
Melanie, from Sherwood in Nottingham, is campaigning to raise awareness of hidden heart defects in young people and the importance of learning CPR. She said she was guided by a 999 call handler to perform CPR on her son until paramedics arrived.