Everything you described sounds like a neuropathy secondary to a brachial plexus issue, it can be bilateral or unilateral, but get it checked out because it can be secondary to something else.
Various contributors to it: arthritis, sports injuries, accidents, C Spine injuries, tumors, etc. Nothing wrong with seeing a chiropractor and your regular doc should refer you to Ortho for a check up, not say they never heard of it. Never heard of a cardiac factor contributing to it, but you never know.
I get them all the time. I do exercise simply because if I don't, it'll get worse. Lot's of Motrin/Tylenol, H2O, and caffeine and moving around even when it hurts.