Although some studies have shown otherwise that exercising too much may not be bad for your heart.
In reality too much exercise can stress out your heart too much when you get the heart working too hard to pump blood.
The heart could give out from being overworked.
So while exercise is good for your heart and overall health too much exercise can actually kill you.
Take for example some athletes that have died during exercise "especially in the heat" those athletes overworked their heart and stressed it out too much which caused them to collapse and die.
So yes exercising too much can actually cause a heart attack.
So yes exercise but don't overdo the exercise.