The injury is permanent and permanently reduces the hearts capacity. He will never be an outstanding athlete or be able to physically function at high and perhaps even moderate levels. He will always be more winded than others on simple hikes or climbing stairs and will never be able to do low energy work for extended periods of time without getting winded. NEVER EVER HIS WHOLE LIFE. People will not understand and view him as lazy or way out of shape. He will not be picked for projects or teams because he will develop a reputation for being weak or lazy because he will always need to "take a break" when others don't. People will not choose him or her for a mate so their dating and marriage options will be more limited because they will be crippled (whether people know why or just experience it when dating them) and most people prefer to date or marry non crippled people if they can. This shunning at a young age especially will also cause antisocial behavior and anger issues. and he will ALWAYS be SUBSTANTIALLY more at risk of a heart attack doing even mild exertion HIS WHOLE LIFE. If they don't know this they may get continue doing simple exertions that could cause them to die and if they DO know this they may live in fear of doing simple exertions their whole life and therefore have a much more limited lifestyle and chronic fear issues. Heart muscle NEVER grows back or repairs PERMANENTLY reducing the hearts strength. And having damaged heart muscle changes the electrical patterns of your heart beat which can make it become unsychronized during any changes in heart beat speed like during exertion or drinking coffee with caffeine causing death by atrial fibrillation or "AFib". This will also give you a 5x greater chance of experiencing a stroke which leads to permanent brain damage.