<s>[INST] I have been having pain in my back located under my left sholder which I can feel thourgh my chest for a few weeks. The pain is medum in the back and light through the chest. it seems to be at its worst in the am. Could this be related to heart issues? [/INST] It is more likely to be muscular than heart-related. Cardiac pain is much more associated with exertion. However, cardiac chest pain must be ruled out, especially if you are in your 40's or beyond. But if you get physical treatments to the shoulder blade, such as massage or physical therapy, that fully resolves the pain, then it would be more clearly muscular. </s>