While I'm not a cardiologist, a limit on the number of times a person can get heart attacks in their lives seems like a joke to me.
What a heart attack is is a hardening of fatty deposits in your arteries, leading to your heart being starved of oxygen
and nutrients. This leads to the death of some heart muscles.
From that description, a limit doesn't make much sense. Your question worries me though, if you think you've had a heart attack (or a friend has had one), get to the hospital and get it checked out! If you've had one heart attack, EVEN A MILD ONE, you could be at a much greater risk for getting another one.
If you've had one or think you might be at risk for one, go talk to a doctor. Your primary care
physician would be a good starting point (they'll be able to tell whether you need more tests), but if that's not an option just go ask a pharmacist, they typically have great medical advice
. If possible it is much better to see a doctor though.
In order to help prevent future heart attacks as much as possible, it's important to exercise daily (U.S. Gov't recommendations have recently been upped from 30 mins, 3 times a week, to 45 minutes to an hour a day) to strengthen your circulatory system, eat a healthy (lower fat, and focusing more on the good fats, as well as replacing sugars / processed carbs like white bread with whole grain breads, rice, and vegetables and fruits), and (after discussion with a doctor!) beginning an aspirin
regimen like taking low-dose bayer aspirin (listed in sources) once a day. It's important to discuss that last one with your doctor, as it may not be necessary and it does impact the way your body works.
I hope some of what I said will be helpful, even though I rambled most of it.