Constrictive Pericarditis

Thickened, fibrotic and sometimes calcified pericardium that restricts diastolic filling, so right and left atrial and ventricular diastolic pressures equalise. Systolic function is usually preserved.

• Causes: idiopathic or viral (commonest in high income settings), tuberculosis (commonest in endemic areas; constriction develops in about 20 to 30% of treated tuberculous pericarditis), post-cardiac surgery, radiation therapy, post-purulent pericarditis, connective tissue disease, uraemia, malignancy, trauma, and asbestos exposure. After viral pericarditis constriction occurs in fewer than 1%, after bacterial pericarditis in about 20 to 30%.
• Transient constriction (about 10 to 20% of cases) occurs in the first months after acute pericarditis, with inflammation, and can resolve with anti-inflammatory therapy. Chronic constriction is irreversible and needs surgery.
• Radical pericardiectomy has a perioperative mortality of about 5 to 15% (higher with radiation, renal failure and advanced disease) and 5-year survival of about 70 to 85% in idiopathic disease, about 30 to 60% after radiation.

• Fatigue, exertional dyspnoea, peripheral oedema, abdominal distension (ascites often out of proportion to leg oedema), anorexia, weight loss, and cachexia in advanced disease.
• Signs: raised jugular venous pressure with a prominent y descent, Kussmaul sign (paradoxical rise in jugular venous pressure on inspiration), pericardial knock (early diastolic sound 0.09 to 0.12 seconds after the second heart sound), hepatomegaly, ascites, pleural effusions, pulsus paradoxus in a minority, and atrial fibrillation (20 to 30%).
• Differential diagnosis: restrictive cardiomyopathy (amyloid, sarcoid, endomyocardial fibrosis), cirrhosis, nephrotic syndrome, tricuspid regurgitation, pulmonary hypertension, right ventricular failure, tamponade, superior vena cava obstruction.
• Complications: refractory right heart failure, cardiac cachexia, protein losing enteropathy, hepatic fibrosis (cardiac cirrhosis), renal impairment, atrial fibrillation, thromboembolism, and myocardial atrophy.

• ECG: low voltage, non-specific T wave abnormality, atrial fibrillation. Chest X-ray: pericardial calcification (about 20 to 40%, more in tuberculosis), pleural effusions, normal heart size.
• Echocardiography: septal bounce (early diastolic shift), respiratory shift of the interventricular septum, mitral inflow E velocity variation greater than 25% with respiration, hepatic vein diastolic flow reversal on expiration, plethoric inferior vena cava, and preserved or increased medial mitral annular e' velocity (8 cm/s or more, often greater than lateral e', called annulus reversus), which separates constriction from restriction.
• CT or cardiac MRI: pericardial thickness greater than 4 mm (though 15 to 20% of cases have normal thickness), calcification, tubular ventricles, dilated atria and vena cavae; late gadolinium enhancement or oedema signals active inflammation and possible reversibility.
• Natriuretic peptide is usually only mildly raised (higher in restrictive cardiomyopathy).
• Cardiac catheterisation when non-invasive tests are unclear: equalisation of end diastolic pressures within 5 mmHg, dip-and-plateau (square root) sign, and discordant respiratory changes in left and right ventricular systolic pressure (systolic area index greater than 1.1).
• Search for the cause: tuberculosis tests (Xpert, culture, adenosine deaminase), HIV test, CRP, ESR, antinuclear antibody, renal function, thyroid stimulating hormone, history of radiation or surgery.

• Confirm whether constriction is transient, because anti-inflammatory therapy can avoid surgery.
• Transient or inflammatory constriction (recent pericarditis, raised CRP, enhancement on MRI):
  • Ibuprofen 600 mg 8-hourly (maximum 2400 mg/day) or aspirin 750 to 1000 mg 8-hourly, tapering over several weeks, with omeprazole 20 mg daily.
  • Colchicine 0.5 mg twice daily (once daily if weight less than 70 kg) for 3 months.
  • Prednisolone 0.25 to 0.5 mg/kg/day for those who fail or cannot take NSAIDs, tapered over weeks.
  • Reassess clinically and with echocardiography after 2 to 3 months.
• Tuberculous constriction: 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. Refer for surgery if constriction persists after 4 to 8 weeks of treatment or deteriorates; operating earlier (within weeks) lowers the risk of dense fibrosis.
• Symptom control while awaiting surgery:
  • Furosemide 40 to 120 mg daily (or bumetanide 1 to 4 mg daily) with spironolactone 25 to 100 mg daily; avoid over diuresis, as the ventricle is preload dependent. Salt restriction to less than 5 g/day.
  • Avoid beta blockers and calcium channel blockers at high doses, since stroke volume is fixed and the heart rate drives cardiac output.
  • Atrial fibrillation: digoxin 0.125 to 0.25 mg daily for rate control, or low dose amiodarone; anticoagulation with warfarin to INR 2.0 to 3.0 or apixaban 5 mg twice daily (2.5 mg twice daily if two of age 80 or more, weight 60 kg or less, creatinine 133 micromol/L or more).
• Definitive treatment: radical pericardiectomy through median sternotomy, removing the pericardium phrenic nerve to phrenic nerve and including the visceral layer (epicardium) where thickened. Indications: functional class III or IV (breathless on minimal exertion), refractory oedema or ascites, or progressive disease. Refer before cachexia, liver failure and myocardial atrophy develop. Symptoms improve in about 80 to 90%, with full recovery of filling over weeks to months.
• Poor surgical candidates or poor outcomes: radiation constriction, severe myocardial atrophy, renal or hepatic failure, low ejection fraction, and advanced age. Postoperative low output syndrome: dobutamine 2.5 to 10 micrograms/kg/min with careful fluid balance.
• Special groups:
  • HIV: start antiretroviral therapy; use steroids with caution (increased HIV-related cancers have been reported).
  • Radiation constriction: often associated with restriction, valve disease and coronary disease, with a worse surgical outcome.
  • Pregnancy: rare; manage medically where possible with careful diuresis, and operate if refractory failure develops.
  • Children: tuberculosis is the major cause in endemic areas; pericardiectomy after anti-tuberculosis treatment fails.
• Red flags: refractory ascites, cachexia, renal impairment, hepatic dysfunction, syncope, new atrial arrhythmia.
• Follow up: review 3 to 6 weeks and at 3 months after surgery, then yearly, with echocardiography, liver and renal function; yearly review for symptomatic recurrence.