Uremic Pericarditis

Etiology

(1) Causes
This condition is a severe complication of chronic renal failure, classified into:

• Uremic pericarditis: Occurs in untreated end-stage renal disease.
• Dialysis-associated pericarditis: Develops during maintenance dialysis.

(2) Pathogenesis
Multiple factors contribute:

1. Toxin accumulation: Urea nitrogen induces chemical inflammation of the pericardium.
2. Immunodeficiency & malnutrition: Increase susceptibility to viral/bacterial infections spreading to the pericardium.
3. Coagulation disorders: Impaired platelet function and fibrinolysis elevate risks of hemorrhagic/fibrinous pericarditis and cardiac tamponade.
4. Metabolic disturbances: Hyperparathyroidism (calcium deposition), hyperuricemia, hypoalbuminemia, and fluid overload exacerbate inflammation.

Pathology: Both types exhibit fibrinous pericarditis with inflammatory cell infiltration, fibrin exudation, and hemorrhage. May progress to pericardial fibrosis or chronic constrictive pericarditis.

Symptoms

Only 6–17% of cases present overt symptoms, often masked by uremia or comorbidities like heart failure. Key features include:

• Chest pain: Worsens when lying flat or during deep breathing.
• Pericardial friction rub: Audible on auscultation (diagnostic hallmark).
• Dialysis-associated cases: Fever, tachycardia, dyspnea, and hypotension during dialysis (potentially fatal).
• Effusion signs: Muffled heart sounds, pulsus paradoxus (with large effusions).

Management

Comprehensive therapy is essential:

1. Diet: Protein-rich, low-sodium, low-phosphorus meals with vitamin/mineral supplements.
2. Fluid restriction: For edema control.
3. Metabolic correction: Lipid-lowering agents, anemia treatment (EPO/iron), and electrolyte balance.
4. Dialysis optimization: Adjust intensity/frequency to reduce toxin load.

Diagnostics

1. Lab tests: Reveal anemia, electrolyte imbalances, and metabolic acidosis.
2. Echocardiography: Detects pericardial effusion.
3. Pericardiocentesis:
   • Uremic type: Sterile serofibrinous/hemorrhagic fluid.
   • Dialysis-associated: Often serosanguinous.

Differential Diagnosis

Exclude other pericarditides (e.g., infective, tuberculous) and uremic myocarditis.

Complications

• Cardiac tamponade (life-threatening).
• Chronic constrictive pericarditis (rare).