It is the aim of these revised guidelines to reflect what the committee has identified as the most important changes to be made in thinking about patients with AMI. Many therapies and procedures in current use are not based on sound scientific evidence. The committee proposes the abandonment of such therapies and procedures that can be identified with confidence. On the other hand, new information suggests that a practical division of all patients with AMI is to classify them as those with ST-segment elevation and those without it. Evidence now shows a distinction in pathoanatomy between the two that demands different therapeutic approaches. Ample evidence exists that persons with suspected MI and ST-segment elevation or bundlebranch block (BBB) should undergo immediate reperfusion, and those without these findings should not. Committee members were selected from cardiovascular specialists with broad geographical representation and combined involvement in academic medicine and primary practice. The Committee on Management of Acute Myocardial Infarction was also broadened by members of the American Academy of Family Physicians, the American College of Emergency Physicians, the AHA Council on Cardiovascular Nursing, and the American Association of Critical-Care Nurses.