Well, those symptoms (palpitations) are not typical for a heart attack
, unless you have some symptoms other than the palpitations (which is the medical term for the ability to feel your heart beating), such a dizziness
, light-headedness, nausea
, or the feeling that you're going to pass out or they're really disrupting your life, I don't think you need to see a doctor about them just yet.
If they really are situational and only happen when you interact with or think about this guy, then you should strongly consider the idea that it's in some way related to your emotional reaction to him, whatever it may be.