Abstract
Acute chest pain suggestive of acute coronary syndrome is a frequent complaint in the emergency department. Acute coronary syndromes include myocardial infarction and unstable angina. Being able to establish the diagnosis rapidly and accurately may be lifesaving. A cardiac workup is indicated in this subset of patients in the acute setting, even if there are no ischemic changes on electrocardiography. If the clinical examination and initial cardiac workup suggest that a patient is having myocardial ischemia, the patient will usually be urgently referred for invasive coronary angiography and revascularization. In stable patients without evidence of ST elevation and ongoing myocardial ischemia, an initially conservative approach is sometimes considered. Cardiac risk stratification of this subgroup of patients who are at low and intermediate risk for coronary artery disease is recommended before discharge, and imaging is necessary to exclude ischemia as an etiology. Noninvasive cardiac imaging modalities include chest radiography, single photon-emission CT myocardial perfusion imaging, echocardiography, multidetector CT, PET, and MRI. Noncardiac etiologies of chest pain include aortic dissection, aortic aneurysm, pulmonary embolism, pericardial disease, and lung parenchymal disease. Noninvasive cardiac imaging in patients who are at low and intermediate risk for coronary artery disease may improve confidence regarding the safety of discharge from the emergency department. In addition to risk stratification, noncoronary etiologies for chest pain can be established with imaging.
