How do a heart attack and angina differ?

Chest pain: "angina" is the medical term for pain that comes from a lack of blood flow to the heart. A "heart attack" is heart damage that results from said lack of blood flow. Frequently, the two go hand in hand.

Continuum: Angina can be quite severe and respond to rest, oxygen, nitroglycerin. And fully recover with no muscle death. The pain fibers are the same source. Some myocardial infarction can be asymptomatic all the way to the worst, ominous, pain ever! there is heart muscle death as the defining entity may need surgery or intervention.