Sudden onset of chest pain and tightness, very uncomfortable, up into left shoulder and halfway down to elbow. mild nausea. lasted approx 3 hours.

To ER for eval : You need to go to the nearest ER ASAP. There are several differential diagnoses which include life threatening condition. You need detail physical examination, and lab, cardiac work up etc.

GE reflux ?: Gastroesophageal reflux, also commonly known as heartburn, has signs and symptoms that can mimic a myocardial infarction. Because nausea was the main symptom, it is unlikely this a cardiovascular problem. BUT, because of the arm pain and numbness, you should check things out with your cardiologist immediately, and possibly have an EKG and a stress test to be sure.