I have had a pain in my shoulder that sends tingling down my left arm and numbness in my hand. What should I do?

Get an EMG/NCT. Paresthesia ; numbness in the hand and arm indicates nerve impingement. See a neurologist for an emg/nct. If proven to have nerve impingement in the neck then you will be referred to a neurosurgeon. If you have impingement of nerves at the elbow or hand , then you will be referred to a hand surgeon for surgical decompression.
Shoulder/ neck. The tingling down arm and numbness in hand represents irritation of nerves in the neck the source of problem is in the cervical region of your neck and not the shoulder you need to be evaluates for pinched nerve in neck.
Be seen. The most likely cause is a cervical Radiculopathy, which is basically a pinched nerve in the neck. But because of the association of cardiac disease and left shoulder and arm complaints, you would be well served to be seen.
Need a diagnosis. Difficult to determine without an examination. Differential diagnosis could be shoulder pathology, cervical radiculopathy (pinched nerve in neck), brachial plexopathy, peripheral nerve entrapment such as carpal tunnel syndrome (not uncommon for cts pain to travel up the arm), or even myofascial pain with trigger points. Would suggest physiatric evaluation for definitive diagnosis and treatment.
Could be shoulder v . This could be a shoulder issue or neck problem. Both can present with the same symptoms. This can be a shoulder issue with some instability causing nerve symptoms into arm with the pain centered in the shoulder or a lateral cervical disc herniation creating shoulder pain and nerve symptoms down the arm or even a combination of both! a thorough evualuation by exam & appropriate imaging is needed.

Related Questions

Post left pneumonectomy pain in left arm, shoulder and hand. Work on a computer 7hrs/day. What is causing numbness/pain/tingling in my left arm?

Could be from. The procedure( irritation of pinching of the nerve ) but also you may have unrelated cervical or lower thoracic degenerative disease that is causing the symptoms. I believe you need to see either a neurologist have and through evaluation and run certain test like nerve conduction test and possible MRI of the cervical and upper thoracic region . Clinically you have neuropathy. Read more...
Nerve impingement. You don't say why at 27 you had "pneumonectomy". Either it is a result of the underlying problem or a nerve could have be impinged upon or damaged by the procedure itself or simply by positioning during anesthesia. It can take a long time for damaged nerves to recover. Meanwhile they be distorting the information regarding pain, sensation, hot/cold and touch going to the brain and info to arm. Read more...