Hello and Welcome to ‘Ask A Doctor’ service.
I have reviewed your query and here is my advice.
Pain in shoulder along with
radiation to arm on the same side is usually due to the following reasons:
Frozen shoulder.
Muscles strain around shoulder.
Rarely related to heart ailments.
Hence EKG is a must to rule out any cardiac problems and if abnormal then to go for full cardiac check-up.
IF cardiac is normal, consult an Orthopedic Surgeon for clinical evaluation, examination and further investigations as would be advised by him.
May need an
MRI and other investigations to know the exact cause.
Proper diagnosis gives a chance for proper management.
Till then take an anti-inflammatory like
Ibuprofen if it suits you, give rest to the ailing part.
Hope I have answered your query.
Let me know if I can assist you further.