What are the differential diagnoses for chest pain?

Differential Diagnosis for Chest Pain

Life-Threatening Causes Requiring Immediate Exclusion

The initial evaluation must prioritize identification of acute coronary syndrome (ACS), aortic dissection, pulmonary embolism, tension pneumothorax, and esophageal rupture—conditions that can rapidly progress to death without urgent intervention. 1, 2

Acute Coronary Syndrome (ACS)

• Presentation: Deep substernal pressure, heaviness, squeezing, or tightness that builds gradually over minutes (not seconds), characteristically diffuse and difficult to localize, with radiation to left arm, jaw, or neck substantially increasing likelihood of myocardial ischemia. 1, 2, 3
• Associated symptoms: Diaphoresis, dyspnea, nausea, syncope, or palpitations significantly increase probability of ACS. 1, 2
• Physical findings: Tachycardia, hypotension, pulmonary crackles, S3 gallop, new mitral regurgitation murmur—but examination may be completely normal in uncomplicated myocardial infarction. 1, 2, 3
• Critical pitfall: Sharp or pleuritic chest pain does not exclude ACS; approximately 13% of patients with pleuritic-type pain have acute myocardial ischemia. 2

Aortic Dissection

• Presentation: Sudden-onset "ripping" or "tearing" chest or back pain that is maximal at onset, radiating to upper or lower back. 1, 2, 3
• Physical findings: Pulse differential between extremities (present in ~30% of patients, more common in type A dissections), systolic blood pressure difference >20 mmHg between arms, new aortic regurgitation murmur (40-75% of type A dissections). 1, 2
• Risk factors: Connective tissue disorders (Marfan syndrome), advanced age, arterial hypertension, atherosclerosis. 1, 4
• Diagnostic triad: Severe abrupt pain + pulse differential + widened mediastinum on chest X-ray confers >80% probability of dissection. 1, 2

Pulmonary Embolism (PE)

• Presentation: Acute dyspnea with pleuritic chest pain (pain worsening with inspiration). 1, 2, 3
• Physical findings: Tachycardia present in >90% of patients, tachypnea >20 breaths/min in ~70%, accentuated P2 heart sound. 1, 2
• Critical action: Calculate Wells score or use clinical gestalt to estimate PE probability before ordering D-dimer or CT pulmonary angiography. 2

Tension Pneumothorax

• Presentation: Dyspnea and sharp chest pain intensifying with inspiration. 1, 2, 3
• Physical findings: Unilateral absence or marked reduction of breath sounds, hyperresonant percussion, hemodynamic instability (hypotension, tachycardia) indicates tension physiology. 1, 2, 3

Esophageal Rupture (Boerhaave Syndrome)

• Presentation: Severe chest pain typically following forceful emesis, painful tympanic abdomen. 1, 2
• Physical findings: Subcutaneous emphysema on neck or chest examination, concurrent pneumothorax in ~20% of cases. 1, 2

Serious Cardiac Causes (Non-ACS)

Pericarditis

• Presentation: Sharp, pleuritic chest pain that worsens when lying supine and improves when sitting forward or leaning forward. 1, 2, 3
• Physical findings: Pericardial friction rub (absence does not exclude disease), fever commonly present. 1, 2, 3

Myocarditis

• Presentation: Chest pain with fever, signs of heart failure. 1, 2, 3
• Physical findings: S3 gallop, clinical presentation mimics ACS requiring cardiac troponin measurement for differentiation. 1, 2

Valvular Heart Disease

• Aortic stenosis: Characteristic systolic murmur with delayed or diminished carotid pulse (pulsus tardus/parvus). 1, 2, 3
• Aortic regurgitation: Early diastolic murmur at right sternal border with rapid carotid upstroke. 1, 2, 3
• Hypertrophic cardiomyopathy: Displaced left ventricular impulse, prominent "a" wave in jugular venous pressure, systolic murmur that increases with Valsalva. 1, 2

Pulmonary Causes

Pneumonia

• Presentation: Fever with localized chest pain, often pleuritic in character. 1, 2, 3
• Physical findings: Regional dullness to percussion, egophony, pleural friction rub may be present. 1, 2, 3

Pneumothorax (Non-Tension)

• Presentation: Dyspnea and pain worsening with inspiration. 1, 2, 3
• Physical findings: Unilateral absence of breath sounds, hyperresonant percussion. 1, 2, 3

Gastrointestinal Causes

Gastroesophageal Reflux Disease (GERD) / Esophagitis

• Presentation: Burning retrosternal pain related to meals or occurring at night, often worsened by stress and relieved by antacids. 1, 2, 3
• Duration: Can last minutes to hours. 3
• Critical pitfall: Esophageal spasm may respond to nitroglycerin; therefore nitroglycerin response should NOT be used to differentiate cardiac from esophageal chest pain. 1, 2

Peptic Ulcer Disease

• Physical findings: Epigastric tenderness on examination, pain may radiate to chest. 1, 2, 3

Gallbladder Disease

• Physical findings: Right upper quadrant tenderness with positive Murphy sign. 1, 2, 3

Musculoskeletal Causes

Costochondritis / Tietze Syndrome

• Presentation: Chest pain reproducible with chest wall pressure, affected by palpation, breathing, turning, twisting, or bending. 1, 2, 3
• Physical findings: Tenderness of costochondral joints on palpation. 1, 2, 3
• Prevalence: Accounts for approximately 43% of chest pain presentations in primary care when cardiac causes are excluded. 2
• Critical pitfall: Presence of chest wall tenderness does not completely exclude ACS; up to 7% of patients with reproducible tenderness still have ACS. 2

Dermatologic Causes

Herpes Zoster

• Presentation: Pain in dermatomal distribution triggered by touch, burning or tingling quality affecting skin surface, strictly unilateral and does not cross midline. 1, 2, 3, 5
• Physical findings: Characteristic unilateral vesicular rash following dermatome, hyperesthesia or allodynia over affected dermatome. 1, 2, 5
• Timing: Pain may precede rash appearance. 5

Immediate Diagnostic Algorithm (First 10 Minutes)

1. Obtain 12-lead ECG within 10 minutes of presentation and interpret for ST-elevation, ST-depression, T-wave inversion, or other acute ischemic changes. 1, 2, 3, 5

2. Measure high-sensitivity cardiac troponin immediately when ACS is suspected; it is the most sensitive and specific biomarker for myocardial injury. 1, 2, 3, 5

3. Perform focused cardiovascular examination assessing pulse and blood pressure differentials between arms, new murmurs, pericardial rubs, unilateral breath sounds, and signs of hemodynamic instability. 1, 2, 3

4. If ST-elevation or new ischemic changes present OR troponin elevated: Activate emergency medical services for immediate transport to emergency department, initiate dual antiplatelet therapy and anticoagulation. 2, 5

5. If initial ECG and troponin normal: Repeat troponin at 3-6 hours; a single normal hs-cTn does not rule out ACS. 2

6. Obtain chest radiograph to evaluate for pneumothorax, pneumonia, pleural effusion, or widened mediastinum. 3

High-Risk Features Requiring Immediate EMS Transport

• Age >75 years with accompanying dyspnea, syncope, acute delirium, or unexplained fall. 2, 5
• Women presenting with atypical symptoms (nausea, fatigue, throat discomfort). 2, 5
• Patients with diabetes, renal insufficiency, or dementia. 2, 5
• Hemodynamic instability (hypotension, shock). 2, 5
• Associated diaphoresis, dyspnea, nausea, or syncope. 2, 5

Critical Pitfalls to Avoid

• Do not dismiss ACS in women, elderly patients, or individuals with diabetes based on atypical presentations; they frequently present with atypical symptoms including sharp or stabbing pain. 1, 2, 5
• Do not assume a normal physical examination excludes ACS; uncomplicated myocardial infarction can present with a completely normal exam. 1, 2
• Do not rely on nitroglycerin response to distinguish cardiac from non-cardiac chest pain, as esophageal spasm and other conditions also respond to nitroglycerin. 1, 2
• A normal initial ECG does not exclude ACS; 30-40% of acute myocardial infarctions present with a normal or nondiagnostic ECG, and approximately 5% of ACS patients have a normal first ECG. 2
• Patients with suspected ACS initially evaluated in office setting should be transported urgently to ED by EMS—delayed transfer for troponin testing should be avoided. 3