Early detection of AMI and reperfusion offers advantages to emergency department physicians when making diagnostic, therapeutic, and triage decisions. The measurement of serial CK-MB in serum remains the gold standard clinical laboratory test. A recommended enzyme ordering pattern scheme is described in Table 5. Rapidly available CK-MB results (two values separated by 30 to 180 minutes) may (1) prevent emergency department discharge of patients with AMI having nondiagnostic electrocardiographs and (2) allow more rapid use and assessment of thrombolytic therapy with AMI in patients not having diagnostic electrocardiographs. Technology no longer limits the availability of a stat CK-MB from the laboratory. However, each institution will have to assess the real value of a stat CK-MB. The future potential and clinical utility of troponin isoenzymes, CK isoforms, and myoglobin for diagnostic and therapeutic purposes still remain to be shown in real time settings.