Coronary artery disease is the leading cause of death in the United States and a major health problem worldwide. Consequently, there is a need to optimize the early diagnosis of cardiac ischemic events to ensure timely treatment, avoid unnecessary hospital admissions for noncardiac chest pain, and prevent discharge of patients who are experiencing myocardial infarction. The primary diagnostic tools are medical history, physical examination, electrocardiography (ECG), and serum cardiac markers. However, none of these has sufficient diagnostic accuracy for evaluating acute chest pain so that many patients with chest pain require further testing and evaluation to achieve an accurate diagnosis. Additional tests include stress provocation; injection of medication, contrast, or nuclear tracers; and/or cardiac catheterization—all of which carry risks, are costly, and/or are time-consuming. Newer diagnostic methods have extended the clinician's diagnostic capacity in this setting.