Data to be collected will include demographic (including ethnic and race classifications according to NIH guidelines) data and information regarding the index myocardial infarction. Use of beta-blockers at discharge from the coronary care unit will be documented. In addition, beta-blocker use at hospital discharge will be noted. Data for the registry will be obtained from ER notes, admission notes, cardiac catheterization lab reports, medication lists, lab reports, and discharge summaries.