Debbie,
I am sorry your son is going through difficult times. Heart attacks can present in many ways, especially in patients that have many concurrent conditions. Classic symptoms of a heart attack include crushing chest pain over the center of the chest, shortness of breath, sweating, and pain radiating to the left jaw and arm. This is not always the case, however. Additionally, numbess in the neck, shoulder, and arm does not mean it is necessarily a heart attack. This can result from many things as well. One common cause includes a pinched nerve in the neck. A proper physical exam and potential MRI could determine if this is the case.
Because these could be serious symptoms, it is important to consult your physicians as he/she can best perform the necessary exams to determine the best course of action.
Hope this helps,
-HealthSupport