Chest Pain Differential Diagnosis
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Direct answer
Chest pain differential diagnosis begins by excluding life-threatening causes, namely acute coronary syndrome, aortic dissection and pulmonary embolism, which carry the highest short-term risk. The character of the pain, its radiation, its relation to exertion or meals, and its posture-dependence separate cardiac, pulmonary, oesophageal and musculoskeletal origins. A twelve-lead electrocardiogram and high-sensitivity troponin are obtained early in every patient with suspicious pain.
What you must remember
- Exertional pressure: crushing retrosternal pain radiating to the left arm or jaw, with sweating and breathlessness, suggests acute coronary syndrome, and the ECG and serial troponin are the key tests.
- Pleuritic pain: sharp pain worse on inspiration suggests pulmonary embolism, pneumothorax or pleurisy, with tachypnoea and hypoxia as supportive features.
- Pericarditis: sharp pain eased by sitting forward, a pericardial rub, and diffuse ST elevation with PR depression rather than a territorial pattern.
- Aortic dissection: abrupt tearing pain radiating to the back, a blood pressure difference of more than 20 mmHg between the arms, and a widened mediastinum on chest X-ray.
- Oesophageal causes: burning pain after meals, relief with antacids and dysphagia suggest reflux or spasm, while Boerhaave syndrome follows forceful vomiting with mediastinal emphysema.
- Musculoskeletal and others: pain reproducible on chest wall palpation suggests costochondritis, herpes zoster causes dermatomal pain before the rash appears, and anxiety is a diagnosis of exclusion.
A 55-year-old diabetic with central pressure for forty minutes
A 55-year-old diabetic man arrives with central chest pressure for forty minutes, sweating and breathlessness.
- Get the ECG early: A twelve-lead ECG is recorded within ten minutes, and aspirin 150 to 300 mg is given unless contraindicated.
- Treat territorial ST elevation: ST elevation in a territorial distribution means reperfusion is urgent, with primary PCI preferred and fibrinolysis used when PCI cannot be delivered in time, per current guideline targets.
- Trend the troponin: If the ECG is non-diagnostic, serial high-sensitivity troponin over several hours separates myocardial injury from its absence, and a risk score such as the HEART score helps decide early discharge versus admission.
- Exclude dissection: Before any anticoagulant or thrombolytic is given, the clinician compares blood pressure in both arms and listens for a diastolic murmur, because these drugs are dangerous when a dissection is present.
- Consider embolism: Pulmonary embolism is considered if the patient is tachycardic with pleuritic pain and recent immobility, and D-dimer or CT angiography follows the usual pathway.
Where the examiner tests the discriminators
Chest pain discriminators are where examiners set most of their traps.
- Trap: Taking relief with sublingual nitrate as proof of angina. Correct: Oesophageal spasm and reflux can also respond to nitrates, so nitrate relief alone does not confirm coronary disease.
- Trap: Diagnosing acute coronary syndrome in a young man with pleuritic pain after a viral illness. Correct: The ECG can mimic acute coronary syndrome, and pericarditis is diagnosed from PR depression and posture-dependent pain.
- Trap: Giving thrombolysis to a patient with a pulse deficit. Correct: A patient with chest pain, a pulse deficit and an ECG suggesting thrombolysis must not receive it until dissection is excluded.
- Trap: Dismissing unilateral pain in an elderly patient. Correct: Herpes zoster precedes its rash by a day or two, so dermatomal pain should prompt a second look at the skin.
Frequently asked questions
Which chest pain features suggest aortic dissection?
Sudden tearing pain radiating to the back, a blood pressure difference of more than 20 mmHg between the arms, and a widened mediastinum on chest X-ray suggest aortic dissection. Anticoagulants and thrombolytics are withheld until dissection has been excluded.
How does pericarditis pain differ from ischaemic pain?
Pericarditis pain is sharp, pleuritic and eased by sitting forward, whereas ischaemic pain is pressure-like and exertional. The ECG in pericarditis shows diffuse ST elevation with PR depression rather than territorial ST changes.
What is the first step in suspected acute coronary syndrome in the emergency room?
A twelve-lead ECG should be obtained within ten minutes of arrival in suspected acute coronary syndrome, with aspirin given unless contraindicated. Serial high-sensitivity troponin then confirms or excludes myocardial injury.
How can oesophageal chest pain mimic angina?
Oesophageal spasm and reflux can produce retrosternal pressure and respond to sublingual nitrates, so nitrate relief alone does not prove coronary disease. Burning pain after meals and dysphagia favour an oesophageal origin.