Mild shooting pain down right arm and into thumb. mild electric/sting/sharp pain. nerve pain? heart issue? not sure what it could be.

Need evaluation: The pain you described is most probably coming from a pinched nerve in the neck See your doctor as you may need Xrays/MRI, followed by medication, physical therapy and nerve blocks

Pain: sounds nerve like in nature, cardiac or heart less likely

Probably nerve pain.: The pain goes to the thumb probably due to some involvement of the radial nerve at the different levels. ( could be neck, shoulder or elbow). I would advise to see neurologist.