Etiology

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• Idiopathic
• Infectious
  • Most commonly viral (e.g., coxsackie B virus)
  • Bacterial (e.g., Staphylococcus spp., Streptococcus spp., or M. tuberculosis)
• Myocardial infarction
  • Postinfarction fibrinous pericarditis: within 1–3 days as an immediate reaction
  • Dressler syndrome: weeks to months after an acute myocardial infarction
• Postoperative (postpericardiotomy syndrome): due to blunt or sharp trauma to the pericardium
• Uremia: e.g., due to acute or chronic renal failure
• Radiation
  • Exudative pericarditis: develops acutely during or after radiation therapy
  • Constrictive pericarditis: develops several years after radiation therapy
• Neoplasms (e.g., Hodgkin lymphoma)
• Autoimmune connective tissue diseases (e.g., rheumatoid arthritis, systemic lupus, scleroderma)
• Trauma

Classifications

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• Serous Pericarditis
  • Viral infection (Coxsackievirus, echovirus, adenovirus)
  • Uremia
  • TB pericarditis (early stage)
  • Rheumatic fever
  • Malignancy involvement
  • SLE, Rheumatoid arthritis
• Fibrous or Fibrinous Pericarditis
  • Most common pericarditis
  • MI (Dressler syndrome)
  • Rheumatic fever
  • Uremia
  • TB pericarditis
  • Malignancy involvement
  • Pericardial surface covered by shaggy, fibrinous exudate
  • “Bread and Butter” appearance
• Purulent (Suppurative) Pericarditis
  • Pyogenic bacteria (Staphylococci, Streptococci, Pneumococci)
  • Direct extension / hematogenous or lymphatic spread / direct implant
  • Severe acute infection
  • Pericardial surface covered by purulent exudate and infiltrated by neutrophils
• Hemorrhagic Pericarditis
  • Malignancy involvement
  • TB pericarditis
  • Severe acute infection
  • Admixture of inflammatory effusion with blood

Clinical features

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• Pleuritic chest pain (↓ when sitting up) ± fever
• Pericardial friction rub
• ECG: diffuse ST-segment elevation
• Pericardial effusion on echocardiogram

Diagnostics

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Acute pericarditis

ECG features of pericarditis

Not all patients go through all stages and manifestations may vary. In particular, pericarditis due to uremia may not involve characteristic ECG changes. Stage 1: diffuse ST elevations, ST depression in aVR and V1, PR segment depression Stage 2: ST segment normalizes in ∼ 1 week. Stage 3: inverted T waves Stage 4: ECG returns to normal baseline (as prior to onset of pericarditis) after weeks to months.

In contrast to myocardial infarction, pericarditis is characterized by a diffuse distribution of ST elevations on ECG.See also “Differential diagnoses of ST elevations on ECG.”

- First, the diffuseness of the ST elevations (I, II, III, aVF, V3-V6). In myocardial infarction the ST elevations tend to be localized (inferior, anterior, posterior, lateral), often, but not always with reciprocal ST depressions. - Second, the PR segment displacement which has been attributed to subepicardial atrial injury.

Chronic pericarditis

• Imaging
  • CT and cardiac MRI
    • Pericardial thickening > 2 mm
    • Calcifications