Yes if you're lucky and get medical help and medical attention soon enough after a massive heart attack you can recover from the massive heart attack and live a normal life and normal lifespan.
I've know 2 people who had massive heart attacks at 50 years old and 60 years old and recovered fully and are doing well 20 years later.
Some people who have massive heart attacks or any heart attacks die if they don't get medical attention.
If you have a massive heart attack or any other heart attack you need to change your lifestyle and start eating healthy and exercising to help improve your heart health.
If you're about to have a heart attack you need to call 911 if possible and if you have some aspirin you should chew some aspirin while calling 911.
Take an aspirin and chew a single full-sized 325-mg tablet, but don't use an enteric-coated tablet, which will act slowly even if chewed.