Too lazy to open the article.
Maybe a defect that was there for a long time?
I had a friend find out he had a potentially deadly heart condition in his 20s. Doctor said it had been there all his life very likely.
One of my friends daughters had heart problems when she was 19. She played on the high school volleyball and was very athletic. She started vomiting after a game and they rushed her to the hospital, she was in emergency surgery 1/2 hour later. She had a congenital heart defect that she was born with. Fortunately, she made a full recovery and has two beautiful children.