Acute Pericarditis

A 30 year old male presents to the emergency department with central chest pain for the past few days. The pain is pleuritic and positional, worsening with inspiration and improving when sitting up and leaning forward. He reports a recent history of fever, myalgia, and sore throat two weeks prior. On examination, a pericardial friction rub is heard over the left parasternal region. Laboratory studies show elevated CRP and ESR with normal or mildly elevated troponin levels. ECG demonstrates diffuse concave ST-segment elevation and PR-segment depression without a territorial pattern or significant reciprocal changes (except aVR). Diagnosis?

Diagnosis is Acute Viral (Idiopathic) Pericarditis.

1. Definition

Acute pericarditis is inflammation of the pericardium, most commonly viral or idiopathic, characterized by pleuritic chest pain, pericardial friction rub, and typical ECG changes.

2. Etiology

1. Viral or idiopathic most common
2. Common viruses include coxsackievirus, echovirus, influenza, and adenovirus
3. Bacterial causes, including tuberculosis
4. Autoimmune diseases such as SLE and rheumatoid arthritis
5. Post-cardiac injury syndromes including Dressler syndrome
6. Malignancy
7. Uremia
8. Drug-induced or radiation-related

3. Pathophysiology

1. Inflammation of visceral and parietal pericardium
2. Leads to friction, causing pleuritic positional chest pain
3. Produces diffuse ST elevation and PR depression
4. May result in pericardial effusion
5. Rapid accumulation of fluid can lead to cardiac tamponade

4. Clinical Features

4.1 Diagnostic Criteria, at least 2 required

1. Pericardial chest pain
2. Pericardial friction rub
3. Diffuse ST elevation or PR depression
4. New or worsening pericardial effusion

4.2 Additional Features

1. Pain radiating to trapezius ridge
2. Dyspnea
3. Low-grade fever
4. Pain relieved by leaning forward

5. Diagnostic Evaluation

5.1 Electrocardiography

1. Diffuse concave ST-segment elevation
2. PR-segment depression
3. Reciprocal PR elevation and ST depression in aVR
4. No territorial pattern

5.2 Laboratory Findings

1. Elevated CRP and ESR
2. Troponin normal or mildly elevated
3. Significant elevation suggests myopericarditis

5.3 Imaging

1. Echocardiography recommended in all patients to assess for pericardial effusion and tamponade
2. Chest X-ray usually normal unless large effusion
3. CT or MRI if diagnosis is uncertain

6. Management

6.1 First-line Therapy

1. NSAIDs such as ibuprofen, indomethacin, or aspirin
2. Colchicine for 3 to 6 months to reduce recurrence
3. Proton pump inhibitor for gastric protection

6.2 Refractory or Specific Cases

1. Corticosteroids reserved for:
• Autoimmune pericarditis
• NSAID or colchicine intolerance
2. Avoid routine use in viral pericarditis due to increased recurrence risk

6.3 Additional Measures

1. Restrict physical activity until symptom resolution
2. Treat underlying cause when identified
3. Hospital admission for high-risk patients, including:
• Fever > 38°C
• Large pericardial effusion
• Cardiac tamponade
• Immunosuppression
• Trauma
• Myopericarditis

7. Complications

1. Pericardial effusion
2. Cardiac tamponade
3. Recurrent pericarditis
4. Myopericarditis
5. Rarely constrictive pericarditis

8. Key Clinical Insight

Pleuritic, positional chest pain with a pericardial friction rub strongly suggests pericarditis

Diffuse ST elevation with PR depression and no territorial pattern differentiates it from myocardial infarction

9. Exam Level Pearls

1. Pericardial friction rub is highly specific
2. Diffuse ST elevation distinguishes from STEMI
3. PR depression is characteristic
4. Troponin may be normal or mildly elevated
5. Colchicine reduces recurrence risk