They do, and they take it for their treatment of angina, not for the treatment of an MI. Pt's do not usually call if they have angina and are having an episode they they are controlling well with their NTG. They call when something is different, the pain won't go away after an hour, this pain is worse, or the pain is associated with nausea and vomiting. Without ALS assessment of the cause of the pain NTG could cause a dramatic drop in pressure in the presence of an inferior and right lateral wall MIs, which would have been avoided had a 12-lead been performed and evaluated. So I agree that pt's give it to themselves safely all the time, in the setting of a 911 call I think a more thorough evaluation needs to be done before NTG is given.