In a 67-year-old patient presenting with pleuritic chest pain, what is the most likely working diagnosis?

Working Diagnosis: Pulmonary Embolism Until Proven Otherwise

In a 67-year-old patient presenting with pleuritic chest pain (chest pain with inspiration), pulmonary embolism (PE) must be your primary working diagnosis and should be systematically excluded before considering other etiologies. 1

Why PE is the Priority Working Diagnosis

Pulmonary embolism is the most common serious and potentially life-threatening cause of pleuritic chest pain, accounting for 5-21% of emergency department presentations with this symptom 2, 3. The 2021 ACC/AHA guidelines explicitly identify PE as one of the life-threatening causes requiring immediate evaluation in chest pain presentations 1. In patients over 50 years old, the stakes are even higher, making aggressive workup mandatory.

Clinical Reasoning Framework

The 2019 ESC PE guidelines emphasize that clinical signs and symptoms of acute PE are non-specific 4. Key features to recognize:

• Pleuritic chest pain is typically caused by pleural irritation from distal emboli causing pulmonary infarction 4
• Tachycardia and dyspnea occur in >90% of PE patients 1
• Pain with inspiration markedly reduces the probability of acute coronary syndrome but increases suspicion for PE 1
• Normal oxygen saturation does NOT exclude PE—less than 40% of PE patients have normal arterial oxygen saturation 4

Immediate Diagnostic Approach

1. Assess clinical pre-test probability using validated prediction rules (Wells score or revised Geneva score) 4

2. Perform focused cardiovascular examination looking for:

   • Tachycardia (present in 40% of PE cases) 4
   • Accentuated P2 heart sound 1
   • Signs of hemodynamic instability 4

3. Obtain ECG - may show RV strain patterns (T wave inversion V1-V4, S1Q3T3, right bundle branch block) in more severe cases, though sinus tachycardia may be the only finding 4

4. Chest X-ray - frequently abnormal but non-specific; useful primarily to exclude other causes like pneumothorax or pneumonia 4, 1

5. D-dimer assay - if low/intermediate pre-test probability 4

6. CT pulmonary angiography (CTPA) - definitive imaging for PE diagnosis 4

Critical Differential Diagnoses to Exclude Simultaneously

While working up PE, you must also consider these life-threatening conditions 1:

• Acute coronary syndrome - though chest tenderness on palpation or pain with inspiration markedly reduce ACS probability 1
• Aortic dissection - look for pulse differentials (30% sensitivity), sudden severe pain 1
• Pneumothorax - unilateral absence of breath sounds, dyspnea with inspiration 1
• Pericarditis - pain worse supine, friction rub may be present 1

Common Pitfalls to Avoid

• Do not be falsely reassured by normal oxygen saturation - 40% of PE patients have normal SaO2 4
• Do not rely on chest X-ray to exclude PE - it is frequently abnormal but findings are non-specific 4
• Do not skip pre-test probability assessment - this guides appropriate use of D-dimer and imaging 4
• Do not assume viral pleurisy in a 67-year-old without excluding PE first - while viruses are common causes of pleuritic pain, PE must be ruled out given the age and mortality risk 2

After Excluding Life-Threatening Causes

Only after systematically excluding PE, ACS, aortic dissection, pneumothorax, and pneumonia should you consider more benign diagnoses like:

• Viral pleurisy (most common benign cause) 2, 3
• Musculoskeletal chest wall pain 1
• Costochondritis 1

The key principle: "Think PE" in pleuritic chest pain and diagnose less serious conditions only when pulmonary embolism has been excluded 5. This approach prioritizes mortality reduction in a 67-year-old patient where missing PE could be fatal.