What is the etiology of pericarditis?

Etiology of Pericarditis

Pericarditis has diverse etiologies that can be broadly classified into infectious and non-infectious causes, with viruses being the most common cause in developed countries and tuberculosis being the predominant cause worldwide, especially in developing countries. 1

Infectious Causes

• Viral infections are the most common etiology in developed countries, accounting for 80-90% of cases, with Echovirus and Coxsackie viruses being most frequently implicated 2, 3

• Bacterial infections:

  • Tuberculosis is the leading cause of pericarditis globally, particularly in developing countries where it is often associated with HIV infection, especially in sub-Saharan Africa 1
  • Other bacterial pathogens include Coxiella burnetii and various pyogenic bacteria 2

Non-Infectious Causes

Autoimmune Conditions (Common)

• Systemic lupus erythematosus
• Sjögren syndrome
• Rheumatoid arthritis
• Scleroderma
• Systemic vasculitides (including eosinophilic granulomatosis with polyangiitis, Horton disease, Takayasu disease, Behçet syndrome)
• Sarcoidosis
• Familial Mediterranean fever and other autoinflammatory conditions 1

Neoplastic Causes

• Primary tumors: Rare, most commonly pericardial mesothelioma 1
• Secondary metastatic tumors: More common, particularly from lung cancer, breast cancer, and lymphomas 1, 4

Metabolic Disorders

• Uremia
• Myxedema
• Anorexia nervosa 1

Traumatic and Iatrogenic Causes

• Early onset:

  • Direct injury (penetrating thoracic injury, esophageal perforation)
  • Indirect injury (non-penetrating thoracic injury, radiation injury) 1

• Delayed onset (Pericardial injury syndromes):

  • Post-myocardial infarction syndrome
  • Post-pericardiotomy syndrome
  • Post-traumatic pericarditis
  • Iatrogenic trauma (e.g., following coronary percutaneous intervention, pacemaker lead insertion, radiofrequency ablation) 1

Drug-Related (Rare)

• Lupus-like syndrome: Caused by procainamide, hydralazine, methyldopa, isoniazid, phenytoin
• Antineoplastic drugs: Doxorubicin, daunorubicin (often associated with cardiomyopathy)
• Other medications: Amiodarone, methysergide, mesalazine, clozapine, minoxidil, dantrolene, practolol, phenylbutazone, thiazides, streptomycin, thiouracils, streptokinase, p-aminosalicylic acid, sulfa drugs, cyclosporine, bromocriptine, vaccines, GM-CSF, anti-TNF agents 1

Other Common Causes

• Hypertension
• Chronic heart failure 1

Epidemiological Considerations

• Geographic variation: In developed countries, idiopathic/viral causes account for 80-90% of cases, while tuberculosis accounts for less than 5%. In contrast, tuberculosis is the predominant cause in developing countries 3, 4

• Demographic factors: Men aged 16-65 years have a higher risk for pericarditis (relative risk 2.02) compared to women, with the highest risk difference among young adults 1, 5

• Idiopathic pericarditis: Despite comprehensive evaluation, approximately 85% of cases in developed countries remain classified as "idiopathic," though many of these are presumed to be viral in origin 2, 3

Clinical Implications

• The etiology significantly influences treatment approach, prognosis, and risk of recurrence 3

• Certain features at presentation suggest specific etiologies and worse prognosis:

  • Temperature >38°C (>100.4°F)
  • Subacute course
  • Large pericardial effusion or tamponade
  • Failure to respond to NSAID treatment 3, 6

• Recurrences may occur in approximately 30% of patients with idiopathic or viral pericarditis without preventive therapy 3

• Understanding the etiology is crucial for targeted treatment and prevention of complications, including cardiac tamponade and constrictive pericarditis 6