My 50 yr. Old husband has tingling and numbness feeling in his left arm mainly in his fingers and goes up to his shoulders, what does this mean?

Need evaluation. Difficult to determine without an examination. Agree with others who suggest need for medical evaluation to rule out cardiac causes. However, can also be peripheral nerve entrapment such as carpal tunnel syndrome (not uncommon for cts pain to travel up the arm), cubital tunnel syndrome, or cervical radiculopathy. Would highly recommend evaluation. May need emg/ncv testing.
Could be heart. At 50yo he should be checked out by a medical professional. He may need a stress test and blood pressure/cholesterol determination. Less dangerous is the possibility that he is holding his shoulder too tight from stress and it is pinching the nerves to the armpit. But, better safe than sorry. He might need to be on a daily aspirin. It's time to have this checked out.
See below. This is one of those problems where a visit to your doctor is necessary to figure out what's going on. Only after a thorough evaluation, including examination and possibly labs and other tests, can your doctor correctly diagnose you and treat you effectively.