Recently, the European Society of Cardiology and the American College of Cardiology met to discuss the diagnosis of acute myocardial infarction (AMI). The consensus document published advocated several changes. First, it was suggested that the preferred marker for the diagnosis of cardiac injury was troponin. It also emphasized that elevations of this sensitive marker did not define the mechanism of cardiac injury. Thus, a clinical determination that the mechanism for the troponin elevation is ischemic is essential for the diagnosis of AMI. This change will require clinicians to reorient their thinking about the use of cardiac markers. They will need to be cognizant of the analytic difficulties that many of the assays manifest and the large number of elevations that can occur because of other forms of cardiac injury, which can now be detected by this new more sensitive strategy. The current article will review the thinking that underpins the recommendations of the European Society of Cardiology/American College of Cardiology Task Force in the hope that it will improve clinicians' ability to implement this new strategy in a more facile manner.