To purchase reprints, contact The InnoVision Group, 101 Columbia, Aliso Viejo, CA 92656. Phone, (800) 809-2273 or (949) 362-2050 (ext 532); fax, (949) 362-2049; e-mail, reprints@aacn.org. MYOCARDIAL INFARCTION H.N., a 57-year-old man, arrived in the emergency department with “excruciating” chest pain that he rated as 8 on a scale of 0 to 10 in which 0 equals no pain. Triage decisions were based on the patient’s history (pain, trigger events, and risk factors), results of initial diagnostic tests (expandedlead electrocardiography [ECG] and measurement of creatine kinase–MB [CK-MB] level), and findings on physical assessment. We selected H.N.’s case to contrast the differences in pathophysiology between inferior AMI and myocardial contusion and the differences between the two in interventions for changes in hemodynamic status and heart rhythms.