It not just about the chest pain, for MI, although it is a significant symptom. A good 12 lead, troponin levels and the best history you can extract from the patient will give a better picture. And some times its not chest pain at all. We had a woman who came in with abosolutely no chest pain, but the worst ULQ "stomach" pain. turned out to be her presentation for a MI in her RCA. It really was different! Glad she didnt get a GI cocktail.