Normal serial myocardial marker measurements reduce the likelihood of AMI but do not exclude unstable angina, which still puts the patient at high risk for a subsequent adverse cardiac event. Therefore, patients with possible ACS should undergo some form of objective cardiac testing. Objective cardiac testing defines either the patient's coronary anatomy, cardiac function, or both. Common modalities used include stress electrocardiography, stress echocardiography, resting and/or stress nuclear imaging, stress cardiac magnetic resonance imaging (MRI), and computed tomography coronary angiography (CTCA). Most patients undergo testing during the initial encounter. However, outpatient testing is an option for low-risk patients in whom AMI has been excluded. This option is most useful in reliable patients presenting to a facility where a mechanism exists to arrange this testing.