Hello,
Does this pain increases on activity or on deep breathing, is it associated with 
tingling or numbness.    Considering your cardiac work up is negative, there is possibility of 
gastritis and reflux for heart pain. Avoid fatty, oily and high calorie diet. Have some walk after having food instead of taking rest. 
Have multiple small meals instead of heavy meals. Have regular sleep habits and avoid stress. Eat lots of green leafy vegetables, and fruits. Avoid smoking and alcohol if any. You can get prescribed tab Pan DSR 40 mg before breakfast once a day for 2 weeks. For shoulder and 
arm pain, there is likelihood of 
cervical pain, due to compression of nerves between spine. 
Does this pain increases on neck movement, is it associated with tingling, numbness in arm or any neck trauma, if yes then it supports the diagnosis. Then he'll need x 
cervical spine AP/ Lat view and further may need MRI. Till the time he can have tab 
Neurobion forte once a day which is a nerve vitamin.   Lastly I would suggest you undergo treadmill test to rule out 
heart disease for sure.
Hope I have answered your query. Let me know if I can assist you further. 
Regards,
Dr. Sagar Makode