It sounds like you have exactly the same thing as me! I managed to deal with my palps and chest pains, until this came, not only that because it's different but because as you said, it's so deep within my chest and comes with the heart beat itself. I've had muscular chest pains a hell of a lot, and it doesn't feel a thing like that. When do you most often experience yours? I'm most likely to get them while walking, even just slowly, sometimes just sitting there doing nothing.