Unless you've been using steroids and/or have a history of heart conditions in your family, I don't believe that having a lot of muscles is a risk factor for heart problems.
You gain muscles by working out, so while you were building up your muscles, you also built up your heart!
Simply put, unless you notice any limiting factors during working out (like an abnormally high heart rate) or the opposite: feel faint during the day (which might be due to low blood pressure), I don't think there's anything to worry about.
I suggest you read some more about the relation between power output and your maximal oxygen uptake + heart rate. These factors are all heavily linked and if you have a feeling there's anything wrong with them in your case, you can always ask another question