First: ABCs and an ECG
Vital signs and a 12-lead ECG within 10 minutes of presentation, before a detailed history if the patient looks unwell. IV access and continuous monitoring for anyone with concerning features.
The Can't-Miss Differentials
- Acute coronary syndrome — see ECG & STEMI criteria, risk-stratify with HEART or TIMI
- Pulmonary embolism — assess with Wells Score
- Aortic dissection — tearing pain, radiating to back, pulse/BP differential between limbs
- Tension pneumothorax — sudden dyspnea, absent breath sounds, tracheal deviation, hypotension
- Esophageal rupture (Boerhaave) — often post-vomiting, subcutaneous emphysema
- Cardiac tamponade — Beck's triad: hypotension, raised JVP, muffled heart sounds
History Clues
| Feature | Points toward |
|---|---|
| Tearing, radiates to back | Aortic dissection |
| Pleuritic, worse on inspiration | PE, pneumothorax, pericarditis |
| Exertional, relieved by rest | Stable angina |
| Worse lying flat, better sitting forward | Pericarditis |
| Associated with swallowing | Esophageal cause |
Initial Workup
ECG, troponin (serial if ACS suspected), chest X-ray, and D-dimer if PE is being considered in a low-to-intermediate probability patient. CT angiography if dissection is suspected.