The views expressed by me are for educational purposes only and do not establish a doctor patient relationship.
This is Dr. D.J., experienced Internal Medicine Specialist.
I am here to address your concerns and provide great service.
The severe shoulder pain along with passing out history suggests the likelihodo of vascular cause.
You may be having subclavian steal phenomenon, in this condition, the blood circulation to the arm is reduced.
Reduced blood circulation will cause severe pain and also dizziness.
There may be blockage in the blood vessels as well.
Definitely, a CT angiogram of the upper arm blood vessels should be considered.
This may be related to your pre existing heart condition which can cause reduced blood flow.
Another possibility can be neuralgia meaning inflammation of the nerves supplying your arms.
Herniated disc at the cervical spine or any shoulder rotator cuff muscle degeneration can affect the nerves.
This can be diagnosed by the MRI scans of the cervical spine and the shoulders.
These tests are better ordered by a specialist preferably a vascular surgeon for vascular work up and a neurologist for the nerve related work up.