About This Page
This is a clinician-written, evidence-based guide aligned to the MCC Examination Objectives. It is structured by clinical presentation — the way the MCCQE tests and the way patients actually present. Management reflects current Canadian guidelines (CMA, CFPC, CPS). Always cross-reference with institutional protocols and clinical judgment.
The Bottom Line
- Five must-not-miss causes: ACS, PE, aortic dissection, tension pneumothorax, esophageal rupture (Boerhaave)
- History is the most powerful diagnostic tool: quality (pressure vs sharp vs tearing), onset, radiation, provoking/relieving factors, associated symptoms
- All chest pain patients need: focused history, vitals (including BP in both arms), ECG within 10 minutes, and troponin
- ACS approach: ECG + serial troponin. STEMI = emergent PCI. NSTEMI = risk-stratify (TIMI/HEART score) for invasive strategy timing
- Do not anchor on one diagnosis — 15% of ED chest pain discharges later prove to be ACS. Use structured rule-out pathways
Approach to the Presentation
Chest pain accounts for ~5-8% of all emergency department visits in Canada. The critical first step is identifying patients with life-threatening causes that require immediate intervention. A structured approach begins with: (1) Rapid assessment of hemodynamic stability and ABCs; (2) 12-lead ECG within 10 minutes; (3) Focused history targeting pain characteristics and red flags; (4) Targeted examination including vitals with bilateral BP, cardiac and respiratory auscultation, and chest wall palpation. The differential is broad — spanning cardiac, pulmonary, GI, musculoskeletal, and psychiatric causes — but the exam tests your ability to prioritize and systematically exclude dangerous diagnoses.
Differential Diagnosis
| diagnosis | likelihood | key features | distinguishing test |
|---|---|---|---|
| Acute Coronary Syndrome (UA/NSTEMI/STEMI) | must-not-miss | Substernal pressure radiating to arm/jaw, diaphoresis, dyspnea, risk factors (smoking, HTN, DM, FHx). >20 min duration, not relieved by position | ECG (ST changes) + serial high-sensitivity troponin |
| Pulmonary Embolism | must-not-miss | Pleuritic chest pain, acute dyspnea, tachycardia, hypoxia. Risk factors: immobility, surgery, OCP, malignancy, prior VTE | Wells score + D-dimer (rule out) or CTPA (confirm) |
| Aortic Dissection | must-not-miss | Sudden tearing/ripping pain maximal at onset radiating to back, BP differential between arms, new AI murmur, pulse deficit | CT angiography (CTA) of chest/abdomen/pelvis |
| Tension Pneumothorax | must-not-miss | Acute pleuritic pain + dyspnea, hypotension, tracheal deviation, absent breath sounds, hyperresonance. Often post-trauma or mechanical ventilation | Clinical diagnosis — needle decompression before imaging |
| Esophageal Rupture (Boerhaave) | must-not-miss | Severe pain after forceful vomiting, subcutaneous emphysema (crepitus), Hamman sign (mediastinal crunch), rapid deterioration | CT chest with oral contrast or water-soluble contrast swallow |
| GERD / Esophageal Spasm | common | Burning retrosternal pain worse after meals/lying flat, relieved by antacids. Spasm may mimic angina (relieved by nitroglycerin) | Trial of PPI; upper GI endoscopy if alarm features |
| Musculoskeletal (costochondritis, strain) | common | Sharp, localized, reproducible with palpation or movement. History of exertion, cough, or trauma. No associated dyspnea or diaphoresis | Clinical diagnosis — reproducible chest wall tenderness |
| Pericarditis | common | Sharp pleuritic pain improved sitting forward, worse lying flat. Friction rub. Recent viral illness. Trapezius ridge radiation | ECG (diffuse ST elevation + PR depression) |
| Pneumonia / Pleuritis | common | Pleuritic pain with cough, fever, purulent sputum. Focal crackles, dullness to percussion | CXR + CBC/CRP |
| Anxiety / Panic Attack | common | Hyperventilation, perioral tingling, palpitations, sense of doom. Often younger patient. Diagnosis of exclusion | Normal ECG + troponin + clinical assessment. Rule out organic causes first |
| Herpes Zoster | less common | Unilateral dermatomal burning/pain that precedes vesicular rash by 2-3 days. Older or immunocompromised | Clinical — vesicular rash in dermatomal distribution |
Red Flags & Key History
Symptoms
Pain maximal at onset ("worst pain of my life") — suggests aortic dissection
Pain with exertion, radiation to arm/jaw, diaphoresis — suggests ACS
Pleuritic pain + acute dyspnea + tachycardia — suggests PE or pneumothorax
Subcutaneous emphysema (crepitus in neck/chest) — suggests esophageal rupture or pneumomediastinum
Hemodynamic instability (hypotension, tachycardia, altered consciousness)
Pain reproducible with chest wall palpation — favours MSK (but does not exclude ACS)
Burning quality, postprandial, relieved by antacids — favours GERD
Sharp positional pain improved sitting forward — favours pericarditis
Signs
BP differential >20 mmHg between arms (aortic dissection)
Absent breath sounds + tracheal deviation + hypotension (tension pneumothorax)
New murmur of aortic regurgitation (aortic dissection)
JVD + muffled heart sounds + hypotension (cardiac tamponade — Beck triad)
Pericardial friction rub (pericarditis)
Reproducible chest wall tenderness (MSK — costochondritis)
Unilateral leg swelling (associated DVT suggesting PE)
Approach to Investigation
First-line
12-lead ECG (within 10 minutes)ST elevation (STEMI), ST depression/T inversions (NSTEMI/ischemia), diffuse ST elevation + PR depression (pericarditis), S1Q3T3/RV strain (PE), low voltage + electrical alternans (tamponade). Repeat at 15-30 min if initial normal and suspicion for ACS persists
High-sensitivity troponinAt presentation and at 3 hours (some protocols use 0/1h or 0/2h rapid rule-out with hs-cTn). Rising/falling pattern = acute myocardial injury. Single normal hs-cTn at 3h with low pre-test probability effectively rules out MI
CXR (portable if unstable)Widened mediastinum (dissection), pneumothorax, pleural effusion, pneumomediastinum (Boerhaave), consolidation (pneumonia), cardiomegaly, pulmonary edema
Basic labsCBC, electrolytes, creatinine, glucose. D-dimer only if PE is being considered and pre-test probability is low-moderate (Wells score)
Second-line
CTPAIf PE suspected (high Wells, positive D-dimer, or high clinical suspicion). Contrast-enhanced CT of pulmonary arteries
CT angiography (chest/abdomen/pelvis)If aortic dissection suspected. Do NOT delay for other tests if clinical picture is convincing
EchocardiogramBedside/POCUS if hemodynamically unstable: RV dilation (PE), wall motion abnormality (ACS), pericardial effusion/tamponade, aortic root dilation (dissection)
HEART score or TIMI scoreRisk stratification for suspected ACS when STEMI has been excluded. Guides disposition: low risk (0-3) may be suitable for outpatient follow-up; high risk (>=4) for admission and early invasive strategy
Specialist
Coronary angiographyEmergent for STEMI. Early invasive for high-risk NSTEMI. Not needed if non-cardiac cause established
Stress testing or CTA-coronaryFor low-intermediate risk patients being considered for outpatient rule-out after serial troponins negative
Management Principles
CCS/CCSN ACS Guidelines + CFPC Emergency Management1
Immediate stabilization (all undifferentiated chest pain)
- ABCs, IV access, continuous cardiac monitoring, pulse oximetry
- ECG within 10 minutes of arrival — if STEMI, activate cath lab immediately
- Aspirin 160 mg chewed (unless dissection strongly suspected)
- Nitroglycerin 0.4 mg SL q5 min x 3 for ongoing ischemic pain (avoid if hypotensive, RV infarct, PDE-5 inhibitor use, or suspected dissection)
2
STEMI
- Primary PCI within 90 min (door-to-balloon) at PCI-capable centre
- If PCI not available within 120 min: fibrinolytic therapy (tenecteplase) within 30 min of arrival + transfer for rescue PCI if needed
- DAPT: ASA + ticagrelor (preferred in Canada) or clopidogrel
- Anticoagulation: UFH or enoxaparin
3
NSTEMI / Unstable Angina
- Anticoagulation (enoxaparin or UFH) + DAPT (ASA + ticagrelor/clopidogrel)
- Risk stratification: TIMI or HEART score
- High-risk: early invasive strategy (angiography within 24h)
- Low-risk: conservative approach with serial troponins and non-invasive testing
4
Pulmonary Embolism
- Anticoagulation: DOAC (rivaroxaban or apixaban) for most patients
- Massive PE (hemodynamic instability): systemic thrombolysis (alteplase) or catheter-directed therapy
- Submassive PE (RV dysfunction, stable): anticoagulation + close monitoring; consider advanced therapy if deteriorating
5
Aortic Dissection
- IV beta-blocker (esmolol or labetalol) FIRST — target HR <60, SBP <120
- Add IV vasodilator (nicardipine) AFTER HR controlled
- Stanford A: emergent surgical repair
- Stanford B uncomplicated: medical management + serial imaging
6
Non-cardiac chest pain
- MSK: NSAIDs, reassurance, activity modification
- GERD: PPI trial (omeprazole 20 mg daily x 4-8 weeks), lifestyle modification
- Pericarditis: ASA or ibuprofen + colchicine x 3 months
- Anxiety/panic: rule out organic causes, then address underlying anxiety (CBT, SSRI if recurrent)
Complications & Pitfalls
- Premature closure: Anchoring on MSK or GERD without adequately ruling out ACS — always complete serial troponins before discharge
- Atypical ACS presentations: Women, elderly, diabetic patients may present with dyspnea, fatigue, or nausea rather than classic chest pain — maintain a low threshold for ECG and troponin
- Cocaine-associated chest pain: Can cause both ACS (coronary vasospasm/thrombosis) and dissection — avoid beta-blockers (unopposed alpha stimulation); use benzodiazepines, nitroglycerin, ASA
- Normal ECG does not exclude ACS: 5-10% of MIs have a normal initial ECG — serial ECGs and troponins are essential
- Failure to check bilateral BPs: Missing aortic dissection because BP differential was not assessed
MCCQE1 Exam Tips
- 1The MCCQE tests presentations, not diagnoses. For chest pain, your job is to systematically rule out dangerous causes. The answer to "next best step" for undifferentiated chest pain is almost always ECG + troponin
- 2ACS chest pain: pressure, radiation, diaphoresis, >20 min, not positional. Pericarditis: sharp, pleuritic, improved sitting forward, friction rub. Dissection: tearing, maximal at onset, BP differential
- 3Tension pneumothorax is a CLINICAL diagnosis — do not delay treatment for CXR. Needle decompression (2nd ICS midclavicular or 4th-5th ICS anterior axillary) then chest tube
- 4Canadian ACS guideline: ticagrelor is preferred over clopidogrel for NSTEMI/STEMI (unlike some international guidelines that favour clopidogrel for non-PCI patients)
- 5HEART score <=3 with negative serial troponins = safe for discharge with outpatient follow-up. This low-risk pathway is tested frequently
- 6Cocaine chest pain: treat with benzodiazepines + NTG + ASA. Beta-blockers are CONTRAINDICATED (risk of unopposed alpha-mediated coronary vasospasm and hypertension)
- 7Boerhaave syndrome (esophageal rupture): forceful vomiting + chest pain + subcutaneous emphysema = Mackler triad. Confirm with CT or contrast swallow, NOT endoscopy
- 8If a question describes chest pain with normal ECG and normal troponin at 0h and 3h in a low-risk patient: the answer is safe discharge, NOT admission for further monitoring
practicetest your knowledge on chest painApply what you've learnt with MCCQE1-style questions from the iatroX Q-Bank — cardiovascular and beyond.
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