Pathophysiology
Clinical meaning
The clinician evaluating pericardial effusion must systematically determine the etiology, assess hemodynamic significance, and plan definitive management.
The clinician evaluating pericardial effusion must systematically determine the etiology, assess hemodynamic significance, and plan definitive management. Etiological workup is guided by clinical context: in developed countries, idiopathic/viral causes predominate (up to 50%), followed by malignancy (10-25%), autoimmune (5-15%), bacterial (1-5%), and post-procedural (5-10%). In developing countries and immunocompromised patients, tuberculosis is a leading cause. The Light criteria adapted for pericardial fluid classify effusions as transudative (heart failure, hypothyroidism, nephrotic syndrome) vs exudative (infection, malignancy, autoimmune). Cytology has sensitivity of only 60-90% for malignant effusions; pericardioscopy with biopsy increases diagnostic yield to 95%. Adenosine deaminase (ADA) above 40 U/L in pericardial fluid is highly suggestive of tuberculous pericarditis. The clinician must recognize special scenarios: purulent pericarditis (emergency requiring drainage plus IV antibiotics plus surgical washout), uremic pericarditis (responds to intensified dialysis), post-cardiac injury syndrome (inflammation after MI, surgery, or trauma, treated with NSAIDs plus colchicine), and effusive-constrictive pericarditis (tamponade that persists after drainage due to visceral pericardial constriction, requiring pericardiectomy). Management decisions include observation (small, stable, asymptomatic), medical therapy (anti-inflammatory for pericarditis), pericardiocentesis (tamponade or diagnostic), surgical drainage (purulent, recurrent,...
