Undifferentiated Chest Pain — A Systematic Diagnostic Approach

The answer first

Chest pain is the commonest reason for emergency presentation in adult medicine and the presentation with the highest medicolegal and mortality risk if misdiagnosed. The cause spans at least six organ systems — cardiac, vascular, respiratory, gastrointestinal, musculoskeletal and psychiatric — and the registrar's job is to rapidly separate the six life-threatening causes (the deadly six) from the large majority of benign causes, without missing any of the former and without over-investigating the latter. The cognitive error that kills patients is not the missed rare diagnosis — it is the missed common diagnosis that was atypical in its presentation. ^[1]

The reproducible sequence for every chest pain patient is: ^[1]

1. Assess stability first — ABCDE. The patient in cardiogenic shock, tamponade, tension pneumothorax or massive PE needs resuscitation before the diagnostic work-up.
2. Get the ECG within ten minutes — it is the single highest-yield test in chest pain, it is cheap, it is immediate, and it identifies the STEMI and the STEMI-equivalent that need catheter-lab activation.
3. Characterise the pain — the OPQRST history (Onset, Provocation, Quality, Radiation, Severity, Timing) and the pain-character framework (central crushing, pleuritic, tearing, burning, positional) narrow the differential faster than any investigation.
4. Identify the deadly six — acute coronary syndrome, pulmonary embolism, aortic dissection, tension pneumothorax, cardiac tamponade, oesophageal rupture. Every chest pain patient is screened for all six in the first assessment, even if the presentation seems benign.
5. Risk-stratify — the HEART score for the ACS question, the Wells score for the PE question, the Modified Early Warning Score for the deteriorating patient.
6. Decide: admit, observe, or discharge — based on the working diagnosis, the risk stratification and the response to the initial assessment. ^[1]

The single most dangerous error is premature closure on a benign diagnosis. The young patient with 'musculoskeletal' chest pain who is discharged and dies of aortic dissection two hours later; the woman with 'anxiety' who is having an inferior STEMI; the patient with 'reflux' who has oesophageal rupture — these are not hypothetical scenarios, they are the recurring failures that the systematic approach is designed to prevent. The second error is over-reliance on a single negative test — the normal ECG does not exclude ACS, the normal troponin at the wrong time does not exclude infarction, the normal chest X-ray does not exclude dissection or PE. ^[1]

Viva trap: "What is the single most useful piece of information in the first minute with a chest pain patient?" The honest answer is the pain character and its onset. "Sudden tearing pain between the shoulder blades" is a different patient from "gradual heavy central chest pain over two hours," and the differential generated by that single phrase is sharper than any single investigation. The registrar who asks "describe the pain in your own words" before reaching for the ECG has organised the entire encounter — but the registrar who does not also get the ECG within ten minutes has failed the patient. ^[1]

References11ShowHide

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