There is a possibility you have injured your ribs.
Sometimes it happens that you would have hurt your chest in an accident or trauma and you wouldn't have realized then. The cartilage region where the rib is connected to sternum. This is the weak area and the region where commonly fracture occurs and goes unnoticed. That could be the reason for radiating pain to your heart as well.
The good part you need to know is the treatment for fracture rib is conservative. Overtime, the cartilage grows back closing the fractured area. At the most, a tight band aid is put against the chest which will help fast healing. For pain you can take Tylenol. If there is no relief after a week, I suggest you go to a orthopaedician who will do an X-ray chest.