What are the causes of pericardial rub?

Causes of Pericardial Rub

A pericardial rub is primarily caused by inflammation of the pericardium, with the most common etiologies being viral infections in developed countries and tuberculosis in developing countries. 1

Infectious Causes

Viral Infections

• Most common cause in developed countries (80-90% of cases) 1, 2
• Common viral agents:
  • Enteroviruses (Coxsackie A+B, Echovirus)
  • Cytomegalovirus (especially in immunocompromised patients)
  • Epstein-Barr virus
  • Adenovirus
  • Parvovirus B19
  • Influenza virus
  • Hepatitis C virus
  • HIV 1

Bacterial Infections

• Purulent pericarditis from:
  • Staphylococcus species
  • Streptococcus species
  • Haemophilus influenzae
  • Mycobacterium tuberculosis (most common cause globally, especially in developing countries) 1, 3
• Routes of infection:
  • Direct infection during trauma or surgery
  • Spread from intrathoracic or subdiaphragmatic focus
  • Hematogenous dissemination 3

Non-Infectious Causes

Autoimmune Disorders (5-15% of cases) 1

• Systemic lupus erythematosus
• Sjögren syndrome
• Rheumatoid arthritis
• Scleroderma
• Systemic vasculitides (e.g., eosinophilic granulomatosis with polyangiitis)
• Behçet syndrome
• Sarcoidosis
• Inflammatory bowel diseases

Post-Cardiac Injury Syndromes 1

• Post-myocardial infarction pericarditis (Dressler syndrome)
• Post-pericardiotomy syndrome
• Post-traumatic pericarditis (iatrogenic or accidental)
• Pericarditis after invasive cardiac procedures

Neoplastic Diseases 1

• Primary tumors (rare): pericardial mesothelioma
• Secondary metastatic tumors (more common): lung cancer, breast cancer, lymphoma

Metabolic Disorders 1

• Uremia (in end-stage renal disease)
• Myxedema (severe hypothyroidism)
• Anorexia nervosa

Drug-Induced Pericarditis 1

• Lupus-like syndrome: procainamide, hydralazine, methyldopa, isoniazid, phenytoin
• Antineoplastic drugs: doxorubicin, daunorubicin
• Other medications: amiodarone, methysergide, mesalazine, clozapine, minoxidil

Other Causes 1

• Radiation therapy
• Chronic heart failure
• Hypertension
• Trauma to the chest

Clinical Pearls and Pitfalls

• A pericardial rub is a characteristic finding in acute pericarditis but may be transient or absent in up to 18% of cases 1
• The rub is best heard during end expiration with the patient sitting up and leaning forward 4
• The presence of a pericardial rub is one of the four key diagnostic criteria for acute pericarditis, along with:
  1. Pericarditic chest pain
  2. ECG changes (new widespread ST-elevation or PR depression)
  3. Pericardial effusion (new or worsening) 1
• A pericardial rub does not always indicate constrictive pericarditis, as it may be absent in up to 18% of surgically proven cases 1
• Myopericarditis should be considered when a pericardial rub is accompanied by elevated cardiac biomarkers, suggesting myocardial involvement 1

Remember that while identifying the cause of a pericardial rub, it's crucial to assess for potential complications such as pericardial effusion, cardiac tamponade, or constrictive pericarditis, as these significantly impact morbidity and mortality.