Do you have risk factors for a heart ailment like obesity, smoking, hypertension, stress and
hyperlipidemia. The pain of a heart attack is crushing pain, felt typically behind the breast bone in the centre or left, radiating to the left arm, jaw ,neck and face. There may be associated nausea, palpitations, sweating and shortness of breath along with the pain. You could be having a nerve compression of an exiting cervical nerve root in your neck causing this numbness in the arm.