Chronic Pericardial Effusion

Pericardial effusion persisting more than 3 months. Large chronic effusions (greater than 20 mm) are often asymptomatic, and about one third progress to tamponade, usually after a precipitant such as volume depletion, bleeding, infection or a procedure.

• Causes: idiopathic (about one third to one half of cases), hypothyroidism, tuberculosis, malignancy, heart failure, nephrotic syndrome, cirrhosis, chronic kidney disease, autoimmune disease, pulmonary hypertension, radiation, chylopericardium (thoracic duct injury or obstruction), post-cardiac surgery, and constrictive physiology.
• Effusions from systemic fluid overload (heart failure, nephrotic syndrome, cirrhosis) are transudates, whereas inflammatory, tuberculous and malignant effusions are exudates.

• Often discovered incidentally. Symptoms: dyspnoea, fatigue, chest fullness or heaviness, dysphagia, cough, early satiety, oedema.
• Signs: soft heart sounds, raised jugular venous pressure, hepatomegaly, pulsus paradoxus when pressure is rising, and features of the underlying disease (goitre or slow reflexes in hypothyroidism, lymphadenopathy in malignancy or tuberculosis).
• Differential diagnosis: cardiomegaly from cardiomyopathy, pleural effusion, constrictive pericarditis, pericardial cyst, mediastinal mass, epicardial fat pad, cardiac tumour.
• Complications: tamponade (often precipitated acutely), effusive constrictive disease, recurrence after drainage, constriction, and pericardial infection.

• Echocardiography for size, loculation, thickening and haemodynamic effect, repeated every 3 to 6 months while the effusion persists.
• Blood tests: thyroid stimulating hormone, albumin, urine protein, liver and renal function, natriuretic peptide, HIV test, antinuclear antibody and anti-dsDNA, CRP, ESR, tuberculosis tests.
• CT chest and abdomen for mass, nodes, thoracic duct disease and pericardial thickening; cardiac MRI for pericardial inflammation (late gadolinium enhancement).
• Diagnostic pericardiocentesis with fluid analysis: cell count, protein (exudate if protein greater than 30 g/L, fluid to serum protein ratio greater than 0.5, or fluid to serum LDH ratio greater than 0.6), glucose, Gram stain and culture, acid fast smear, Xpert MTB/RIF and mycobacterial culture, adenosine deaminase (greater than 40 U/L suggests tuberculosis) and cytology. Chyle is milky with triglycerides greater than 5.65 mmol/L (500 mg/dL) and a lymphocyte predominance.
• Pericardial biopsy through a subxiphoid or thoracoscopic window when the cause remains unknown after fluid analysis, particularly with weight loss, fever, or progression.

• Small or moderate asymptomatic effusions: observation and treatment of the cause, with echocardiography every 3 to 6 months.
• Cause directed therapy:
  • Hypothyroidism: levothyroxine, reaching about 1.6 micrograms/kg/day over weeks (start at 25 to 50 micrograms daily if older or with heart disease).
  • Heart failure, nephrotic syndrome, cirrhosis: furosemide 40 to 80 mg daily with spironolactone 25 to 100 mg daily; avoid over diuresis in patients with tamponade physiology.
  • Inflammatory effusion with raised CRP: colchicine 0.5 mg twice daily (once daily if weight less than 70 kg) for 3 to 6 months, with ibuprofen 600 mg 8-hourly tapered over 2 to 4 weeks.
  • Tuberculosis: rifampicin 10 mg/kg (maximum 600 mg), isoniazid 5 mg/kg (maximum 300 mg), pyrazinamide 25 mg/kg (maximum 2 g), ethambutol 15 mg/kg (maximum 1.2 g) daily for 2 months, then rifampicin and isoniazid for 4 months, with pyridoxine 25 to 50 mg daily.
  • Autoimmune: prednisolone 0.5 mg/kg/day, with a steroid sparing agent such as azathioprine 1 to 2 mg/kg/day as specialist advice.
  • Chylopericardium: low fat diet with medium chain triglycerides, octreotide 100 to 200 micrograms SC 8-hourly (evidence limited), and thoracic duct ligation or embolisation if it persists.
  • Malignant: drainage, systemic cancer therapy, and pericardial window for recurrence.
• Pericardiocentesis is indicated for a large effusion (greater than 20 mm) lasting more than 3 months even without symptoms (because of the risk of tamponade), for symptoms, and for diagnosis. Use echo guidance and a pigtail catheter left until drainage is less than 25 mL/24 hours.
• Recurrence after drainage: surgical subxiphoid or thoracoscopic pericardial window, or balloon pericardiotomy; pericardiectomy when constriction develops.
• Avoid abrupt volume depletion (diarrhoea, vomiting, aggressive diuresis, haemorrhage), which can precipitate tamponade.
• Special groups:
  • Pregnancy: observe, treat hypothyroidism, avoid NSAIDs after 20 weeks, and drain for symptoms or tamponade.
  • Children: look for hypothyroidism, tuberculosis and malignancy; ibuprofen 30 to 40 mg/kg/day in 3 divided doses.
  • Elderly: lower threshold for drainage, as small volume changes cause tamponade.
  • HIV and immunosuppression: test early for tuberculosis and cryptococcal disease.
• Red flags: breathlessness, hypotension, rising jugular venous pressure, new tachycardia, weight loss, fever, rapid growth.
• Follow up: echocardiography at 3 to 6 months until resolved or stable for a year; yearly thereafter; refer for window or biopsy if symptomatic or enlarging.