What is the approach to forming a differential diagnosis for a patient with chest pain?

Approach to Differential Diagnosis for Chest Pain

The differential diagnosis for chest pain must prioritize immediate identification of life-threatening conditions—acute coronary syndrome, aortic dissection, pulmonary embolism, tension pneumothorax, and esophageal rupture—before considering more benign etiologies. 1

Immediate Life-Threatening Causes (Exclude First)

Acute Coronary Syndrome (ACS)

• Presentation: Retrosternal pressure, heaviness, tightness, or squeezing that builds gradually over several minutes (not seconds), radiating to left arm, jaw, neck, or back 1
• Associated symptoms: Diaphoresis, dyspnea, nausea, syncope 1
• Key feature: Precipitated by exertion or emotional stress in stable angina; occurs at rest in ACS 1
• Prevalence: 5.1% of ED chest pain presentations, 20-45% in emergency settings 1, 2

Aortic Dissection

• Presentation: Sudden-onset "ripping" or "tearing" chest pain, worst pain of patient's life, radiating to upper or lower back 1
• Physical findings: Pulse differential between extremities (30% sensitivity), blood pressure differential, new aortic regurgitation murmur 1
• Risk factors: Hypertension, known bicuspid aortic valve, aortic dilation, connective tissue disorders (Marfan syndrome) 1

Pulmonary Embolism (PE)

• Presentation: Acute dyspnea with pleuritic chest pain 1, 2
• Physical findings: Tachycardia present in >90% of patients, tachypnea 1, 2
• Key feature: Pain increases with inspiration 1

Tension Pneumothorax

• Presentation: Dyspnea and pain on inspiration 1
• Physical findings: Unilateral absence of breath sounds, hyperresonant percussion 1, 3

Esophageal Rupture

• Presentation: Severe chest pain with painful, tympanic abdomen 1

Serious But Non-Immediately Fatal Causes

Pericarditis

• Presentation: Sharp, pleuritic chest pain that worsens when supine and improves when leaning forward 1, 2
• Physical findings: Friction rub on examination, fever 1, 2
• ECG findings: Widespread ST elevation with PR depression 3

Myocarditis

• Presentation: Chest pain, fever, signs of heart failure 1, 2
• Physical findings: S3 gallop 1, 2

Valvular Heart Disease

• Conditions: Aortic stenosis, aortic regurgitation, hypertrophic cardiomyopathy 1
• Physical findings: Characteristic murmurs and pulse alterations 1

Pneumonia

• Presentation: Localized pleuritic chest pain, fever, productive cough 1, 2
• Physical findings: Regional dullness to percussion, egophony, friction rub may be present 1, 4

Common Benign Causes

Costochondritis/Tietze Syndrome

• Presentation: Tenderness of costochondral joints on palpation 1, 2, 3
• Key feature: Pain reproducible with chest wall pressure 2, 3
• Prevalence: 43% of chest pain in general practice 2
• Critical caveat: Approximately 7% of patients with reproducible chest wall pain still have ACS 3

Gastroesophageal Reflux Disease/Esophagitis

• Presentation: Burning retrosternal pain related to meals, relieved by antacids 2

Musculoskeletal Pain

• Presentation: Pain localized to very limited area, affected by palpation, breathing, turning, twisting, or bending 2, 3

Algorithmic Approach to History Taking

Pain Characteristics (Obtain All Six)

1. Nature/Quality:

• Pressure, heaviness, tightness, squeezing → suggests ischemia 1
• Sharp, increases with inspiration → suggests pericarditis or pleuritic process 1
• Ripping, tearing → suggests aortic dissection 1

2. Onset and Duration:

• Gradual build over minutes → suggests angina 1
• Sudden onset → suggests dissection, PE, pneumothorax 1
• Fleeting (few seconds) → unlikely ischemic heart disease 1

3. Location and Radiation:

• Retrosternal with radiation to left arm, jaw, neck → suggests ACS 1
• Radiation to upper or lower back → suggests aortic dissection 1
• Pain below umbilicus or hip → unlikely myocardial ischemia 1
• Remember: "chest pain" includes shoulders, arms, neck, back, upper abdomen, jaw 1

4. Precipitating Factors:

• Exertion or emotional stress → suggests stable angina 1
• Occurs at rest → suggests ACS 1
• Worsens with inspiration → suggests pleuritic process 1
• Worsens supine, improves leaning forward → suggests pericarditis 1, 2

5. Relieving Factors:

• Critical pitfall: Do NOT use nitroglycerin response as diagnostic criterion—esophageal spasm and other noncardiac conditions also respond to nitroglycerin 2, 3

6. Associated Symptoms:

• Diaphoresis, dyspnea, nausea, syncope → significantly increases likelihood of ACS 1, 2
• Fever → suggests pericarditis, myocarditis, pneumonia 1

Cardiovascular Risk Factor Assessment (Mandatory)

• Age, sex, smoking, hyperlipidemia, diabetes mellitus, hypertension, family history of premature CAD, postmenopausal status 1
• High-risk populations: Women, elderly (>75 years), patients with diabetes, renal insufficiency, or dementia may present with atypical symptoms 2, 3

Comorbid Conditions That Precipitate "Functional" Angina

• Increased oxygen demand: Hyperthyroidism, hyperthermia, cocaine use, aortic stenosis, severe uncontrolled hypertension 1
• Decreased oxygen supply: Anemia, hypoxemia from pulmonary disease, increased blood viscosity 1

Critical Physical Examination Findings

Cardiovascular Examination

• Diaphoresis, tachypnea, tachycardia, hypotension, crackles, S3, mitral regurgitation murmur → suggests ACS (examination may be normal in uncomplicated cases) 1
• Pulse differential between extremities → suggests aortic dissection (30% sensitivity) 1
• Blood pressure differential → suggests aortic dissection 1
• Friction rub → suggests pericarditis 1, 2
• S3 gallop → suggests myocarditis or heart failure 1, 2

Respiratory Examination

• Unilateral absence of breath sounds → suggests pneumothorax 1, 4
• Regional dullness to percussion, egophony → suggests pneumonia 1, 4

Musculoskeletal Examination

• Tenderness to palpation of costochondral joints → suggests costochondritis 1, 2
• Critical caveat: Chest tenderness markedly reduces probability of ACS but does NOT exclude it—7% still have ACS 1, 3

Terminology Recommendations

Avoid "atypical chest pain"—this term is confusing and can be misinterpreted as benign 1

Use instead:

• "Cardiac" → symptoms likely attributable to myocardial ischemia 1
• "Possibly cardiac" → uncertain etiology requiring further evaluation 1
• "Noncardiac" → symptoms clearly not attributable to cardiac causes 1

Common Diagnostic Pitfalls to Avoid

1. Do not dismiss chest pain in women or elderly patients—they frequently present with atypical symptoms including sharp or stabbing pain 2, 3

2. Do not use nitroglycerin response as diagnostic criterion—esophageal spasm and other conditions also respond 2, 3

3. Do not rely solely on reproducible chest wall tenderness—7% of patients with reproducible pain still have ACS; ECG and troponin are mandatory 3

4. Do not assume normal examination excludes ACS—examination may be entirely normal in uncomplicated myocardial infarction 1

5. Do not delay transfer for office-based testing—if ACS suspected in office setting, transfer urgently to ED by EMS, not personal automobile 1, 2, 3

Mandatory Initial Diagnostic Testing

All Patients With Chest Pain

• 12-lead ECG within 10 minutes of presentation, immediately interpreted by experienced physician 1, 2, 3, 4
• High-sensitivity cardiac troponin measured immediately after admission with results within 60 minutes 1, 2, 3

If Initial Testing Suggests Life-Threatening Cause

• STEMI or new ischemic changes on ECG → immediate EMS transport for reperfusion 1, 3, 4
• Suspected aortic dissection → CT angiography, TEE, or MRI; D-dimer if available 1
• Suspected PE → D-dimer, CT pulmonary angiography 1, 4
• Hemodynamic instability → urgent echocardiography 1

If Persistent or Recurring Symptoms Despite Negative Cardiac Workup

• Evaluate for noncardiac causes: respiratory, gastrointestinal, musculoskeletal, psychological 1
• Consider referral to cognitive-behavioral therapist if recurrent presentations with no physiological cause on prior diagnostic evaluation 1