What is a heart pain?

So I have costalchronditis (I think that's how it's spelt) where the cartilage in my ribs is a bit inflamed and sometimes I get pains in my chest from it, like when I go to the gym. I was wondering, how can you tell what a heart pain is? Would I know, or is it easy to p off as something else, like my rib pains? For instance, is it always a dull deep ache, and does it always reach the left arm? My pains are fairly mild, sharp, shallow and localised, even when in centre of ribs. Many thanks :]