How should I evaluate and treat a patient with chest pain that worsens when lying supine or in the lateral decubitus position?

Evaluation and Management of Chest Pain Worsening with Supine and Lateral Decubitus Positioning

Primary Diagnosis: Acute Pericarditis

Chest pain that worsens when lying supine or in lateral decubitus position is pathognomonic for acute pericarditis and effectively excludes pulmonary embolism as the cause. 1

Immediate Diagnostic Workup (First 10 Minutes)

• Obtain a 12-lead ECG within 10 minutes to identify the classic pericarditis pattern: diffuse concave ST-segment elevation with PR-segment depression 2
• Measure high-sensitivity cardiac troponin immediately because approximately 13% of patients with pleuritic chest pain have acute myocardial ischemia, and myopericarditis must be excluded 2, 1
• Assess vital signs including heart rate, blood pressure in both arms, respiratory rate, and oxygen saturation to detect hemodynamic compromise suggesting tamponade 2
• Perform focused cardiovascular examination listening specifically for a pericardial friction rub (present in <30% of cases but highly specific), checking for jugular venous distension, and assessing for signs of heart failure 2, 3, 4

Diagnostic Criteria for Acute Pericarditis

Diagnose acute pericarditis when at least 2 of the following 4 criteria are present: 3, 4

1. Sharp, pleuritic chest pain that worsens supine and improves sitting forward (present in ≈90% of cases) 3, 4
2. Pericardial friction rub on auscultation (present in 18-84% of cases, though often transient) 4
3. New widespread ST-elevation with PR-depression on ECG (present in ≈25-50% of cases) 3, 4
4. New or worsening pericardial effusion on echocardiography (present in ≈60% of cases, typically small) 3, 4

Essential Imaging

• Perform transthoracic echocardiography in all patients to characterize pericardial effusion size, assess for tamponade physiology (diastolic right ventricular collapse, respiratory variation >25%), detect regional wall motion abnormalities suggesting myopericarditis, and exclude aortic dissection 2, 1, 4
• Consider cardiac MRI with gadolinium if diagnostic uncertainty exists or to determine the extent of pericardial inflammation, particularly when troponin is elevated suggesting myopericarditis 2, 1

Risk Stratification for Hospital Admission

Admit patients with any of the following high-risk features: 4

• Fever >38°C (100.4°F)
• Subacute onset (symptoms developing over days to weeks)
• Large pericardial effusion (>20 mm echo-free space)
• Cardiac tamponade (Beck's triad: jugular venous distension, hypotension, muffled heart sounds with pulsus paradoxus >10 mmHg) 5
• Elevated troponin indicating myopericarditis
• Immunosuppressed state
• Trauma history
• Oral anticoagulant therapy
• Failure to respond to NSAIDs within 7 days

First-Line Pharmacologic Treatment

Initiate high-dose aspirin 500 mg to 1 gram every 6-8 hours as the cornerstone anti-inflammatory therapy 1, 3, 4, 6

Add colchicine 0.5-0.6 mg once or twice daily for 3 months to reduce symptoms and prevent recurrence (absolute risk reduction 20.8%, reducing recurrence from 37.5% to 16.7%) 1, 3, 4, 6

• For patients weighing <70 kg, reduce colchicine to 0.5 mg once daily 1
• Continue NSAIDs until chest pain resolves and C-reactive protein normalizes, then taper over several weeks 3, 6

Critical Medications to Avoid

Do NOT use glucocorticoids or non-aspirin NSAIDs as first-line therapy because they increase the risk of recurrent myocardial infarction, impair myocardial healing, and are associated with higher recurrence rates 1, 3, 7, 6

• Reserve glucocorticoids only for patients with contraindications to NSAIDs, pregnancy beyond 20 weeks' gestation, or systemic inflammatory conditions 4, 6

Management of Recurrent Pericarditis

If first recurrence occurs, extend colchicine to at least 6 months 3, 7

For multiple recurrences refractory to NSAIDs and colchicine, consider interleukin-1 blockers (anakinra or rilonacept) as steroid-sparing therapy before resorting to long-term corticosteroids 3, 7, 6

Common Diagnostic Pitfalls

• Do NOT assume reproducible chest wall tenderness excludes cardiac disease—7% of patients with palpable tenderness have acute coronary syndrome 1, 8
• Do NOT rely on nitroglycerin response to differentiate pericarditis from ischemia, as esophageal spasm and other conditions may also improve 2, 1
• Do NOT dismiss the diagnosis if friction rub is absent—it is present in fewer than one-third of cases and is often transient 3, 4
• Recognize that 13% of patients with pleuritic-type chest pain have acute myocardial ischemia, so troponin measurement is mandatory 2, 1

Disposition and Follow-Up

• Low-risk patients (no high-risk features, normal troponin, small or no effusion) can be managed outpatient with close follow-up in 1 week to assess treatment response and check C-reactive protein 4, 6
• High-risk patients require hospital admission for continuous cardiac monitoring and serial assessment for tamponade development 4
• Prognosis is excellent with appropriate treatment—70-85% have a benign course, with <0.5% risk of constrictive pericarditis and <3% risk of tamponade 3, 6