About 2 Weeks Ago, I Started Having Real Sharp Pains

About 2 weeks ago, I started having real sharp pains at my left shoulder blade and then it burns like someone put a lighter to my skin. I had heard that it could be the makings of a heart attack, now instead of burning so much it will itch. Can that be a form of shingles? I can't see or feel any rash, because I have a lot of shin tags. By the way what causes those too and is there a medicine that will make them go away?