Unstable Angina Differential Diagnoses

Updated: Oct 01, 2020
  • Author: Walter Tan, MD, MS; Chief Editor: Eric H Yang, MD  more...
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Diagnostic Considerations

Observation and serial or further testing should be considered for patients who have coronary risk factors or a suspicious history. In one study, the unintentional failure to recognize or hospitalize patients with myocardial infarction or unstable angina occurred in an average of 2.2 per 100 patients presenting to the emergency department with a chest pain syndrome. [23] The rates were 0-10% across different academic centers.

Be aware that unstable angina can infrequently coexist or concurrently present with the following:

  • Aortic dissection with involvement of the right coronary artery ostium

  • Infective endocarditis with embolus into a coronary artery

  • Periprocedural (post−percutaneous coronary intervention) reocclusion or coronary stent thrombosis

  • Congestive heart failure

Also consider cocaine-induced coronary spasm, which can be indistinguishable from acute coronary syndromes. (Nitroglycerin and calcium-channel antagonists are the drugs of choice; beta blockers may exacerbate cocaine-induced coronary vasoconstriction.) In patients with persistent ST elevation, coronary angiography should be performed. If this cannot be carried out immediately, consider empiric fibrinolytic therapy.

Variant (Prinzmetal) angina is characterized by transient ST-segment elevation and can involve multiple coronary arterial territories. Patients typically respond to nitroglycerin and high-dose, and sometimes even dual, calcium channel blockers.

The differential diagnoses for unstable angina fall into the following categories:

  • Cardiac (eg, acute myocarditis and right ventricular strain due to severe pulmonary hypertension)

  • Vascular (eg, microvascular disease [syndrome X])

  • Pulmonary (eg, pneumonia, pneumothorax, pulmonary hypertension, and tracheobronchitis)

  • Gastrointestinal (eg, Mallory-Weiss tear, pancreatitis, and peptic ulcer disease)

  • Musculoskeletal (eg, arthritis of the shoulder or spine, cervical disk disease, interscalene or hyperabduction syndromes, subacromial bursitis, and intercostal muscle cramps)

  • Other (eg, mediastinitis, disorders of the breast, and tumors of the chest wall)

Differential Diagnoses