What Do Heart Palpitaions Followed By Painful Rashes Around Shoulders Suggest?

Hello, I have been suffering for a couple of days...first heart palpatations or spasms. I thought I was having a heart attack. That has diminished somewhat. The problem now is a rash has broken out on my left shoulder blade and wrapped around to my left nipple. The pain of this has been there for the same couple of days, only now the rash is very evident. I have trouble breathing somewhat and it is difficult to get comfortable. I am thinking insect bite? Don t know...please help! Thanks, Jack