Missed acute cardiac ischemia in the ED: limitations of diagnostic testing

Correctly identifying and appropriately triaging patients who present to the ED with the broad range of symptoms suggestive of acute cardiac ischemia (ACI: unstable angina pectoris [UAP] and acute myocardial infarction [AMI]) remains one of the greatest challenges in EM. Although a number of diagnostic technologies have been described to aid in this triage process, each of these tests or technologies has limitations. We report a case series in which either the use of adjuncts with unknown performance or tests with known but not considered limitations could have contributed to the failure to appropriately triage and treat patients with ACI. Each case illustrates different aspects of this clinical challenge. One case illustrates the hazards of reliance on a single set of negative cardiac biomarkers. The limitations of a negative exercise electrocardiographic stress test (ETT) are illustrated in the second case. Finally, the limitations of a negative coronary angiogram, the “gold standard” test for symptomatic coronary artery disease, are discussed. We review the literature on technologies to aid in the evaluation of patients who present to the ED with symptoms suggestive of ACI.