How can you tell the difference between muscle spasms in left back of chest and arms and heart pains in chest that run down arms?

No answer. You cannot tell the difference as a simple answer. Need a direct evaluation by your doctor.
Men and Hearts. A man does not have just one symptom when their heart is in trouble. There are a myriad of symptoms. If you only have muscle pain it is not likely that the problem is your heart.

Related Questions

Unexplained chest pain what could it be have had it for 3 months ruled out heart and gi problems and back of left arm could it be muscles?

Chest pain. Probable radicular discomfort due to nerve root irritation-go see a neurologist to assess. Read more...
R/o pulmonary issues. Given back of arm involvement, neurological cause is most likely, but would at least get an x ray to make sure there is no pleural effusion. Otherwise most likely musculoskeletal. I am assuming that you're otherwise healthy and active. Read more...

Sholder and chest pain and I can feal the sore muscles in my chest and when I move the arm I can feel some pain in my scapula is it heart related?

Not Likely. The symptoms you describe are most likely musculoskeletal in nature. This can occur when you overwork muscles for example with strenous exercise or heaving lifting for example. You do not say if you have any other problems. Cardiac pain is typically substernal, pressure like, with radiation to neck, jaw and sometimes down the arm. Of course, if this should reoccur, you should see you physician. Read more...