Key Facts

Constrictive pericarditis (CP) is a chronic condition in which the pericardium becomes thickened, fibrotic, and sometimes calcified, encasing the heart in a rigid shell that impairs diastolic filling. This leads to signs of right (and eventually biventricular) heart failure.

Epidemiology

• Uncommon in developed countries; more common where TB is prevalent
• Post-cardiac surgery and idiopathic are the leading causes in developed countries
• May develop months to years after the initial pericardial insult
• Occurs in ~1% of acute viral pericarditis cases; higher with TB/purulent/radiation pericarditis

Aetiology

• TB pericarditis: most common cause worldwide
• Idiopathic/post-viral: most common in developed countries
• Post-cardiac surgery: especially CABG
• Post-radiation: mediastinal radiotherapy (Hodgkin lymphoma, breast cancer)
• Prior pericarditis: bacterial (purulent), autoimmune
• Uraemia
• Connective tissue disease: RA, SLE

Pathophysiology

• Chronic inflammation → pericardial fibrosis and calcification → rigid pericardial shell
• Rigid pericardium prevents cardiac expansion during diastole
• Early diastolic filling is rapid (suction effect) but halts abruptly → 'square root sign' on pressure tracings
• Elevated and equalised diastolic pressures in all chambers
• Impaired venous return → systemic venous congestion → elevated JVP, hepatomegaly, ascites, oedema
• Kussmaul sign: during inspiration, increased venous return cannot be accommodated by rigid pericardium → JVP rises

Typical Presentation

• Insidious onset over months-years
• Right heart failure predominates: peripheral oedema, ascites (often disproportionate to peripheral oedema), hepatomegaly
• Fatigue, exercise intolerance
• Dyspnoea (may be minimal despite significant haemodynamic compromise)

Examination Findings

• Elevated JVP with prominent x and y descents
• Kussmaul sign: JVP rises (or fails to fall) during inspiration
• Pericardial knock: early diastolic sound (earlier and higher-pitched than S3)
• Hepatomegaly (may be pulsatile), ascites
• Peripheral oedema
• Non-displaced apex beat (small rigid ventricles)
• AF may be present

Red Flags

• Disproportionate ascites relative to peripheral oedema
• Progressive right heart failure not responding to diuretics
• Cachexia (cardiac cachexia from chronic low output)
• Previous TB or cardiac surgery in a patient with right heart failure

Bedside

• ECG: low-voltage QRS, AF, non-specific T-wave changes
• JVP assessment: elevated with Kussmaul sign

Bloods

• BNP/NT-proBNP: mildly elevated (usually lower than in restrictive cardiomyopathy - helps differentiate)
• LFTs: congestive hepatopathy
• Albumin: may be low (protein-losing enteropathy)
• FBC, CRP: if active inflammation
• TB testing: Mantoux, QuantiFERON-TB

Imaging

• CXR: pericardial calcification (visible in ~25%), small heart
• CT chest: pericardial thickening (>4 mm) and calcification (best modality for calcification)
• Cardiac MRI: pericardial thickening, inflammation (late gadolinium enhancement), ventricular interdependence
• Echocardiography: pericardial thickening, septal bounce (ventricular interdependence), dilated IVC, restrictive filling pattern
  • Respiratory variation >25% in mitral inflow velocity (differs from restrictive cardiomyopathy <15%)

Special Tests

• Cardiac catheterisation: gold standard for haemodynamic assessment
  • Equalisation of diastolic pressures across all chambers (within 5 mmHg)
  • Square root sign (dip-and-plateau pattern) in ventricular pressure tracings
  • Concordant change in RV and LV pressures during respiration (discordant in CP)
  • Actually: CP shows discordant ventricular pressure changes with respiration (RV rises as LV falls)

Non-pharmacological

• Sodium and fluid restriction
• Treat underlying cause (TB, etc.)

Pharmacological

• Diuretics: for symptom relief (furosemide ± spironolactone) - often provide limited benefit
• Anti-TB therapy: if TB aetiology (standard RIPE regimen ± corticosteroids)
• Anti-inflammatory therapy: colchicine, NSAIDs, or corticosteroids if active inflammation (transient constrictive pericarditis may resolve)
• Transient constrictive pericarditis: ~15% of cases resolve with medical therapy alone (usually within 3-6 months)

Surgical/Interventional

• Pericardiectomy: definitive treatment for established constrictive pericarditis
  • Complete resection of both visceral and parietal pericardium where possible
  • Operative mortality: ~5-10% (higher with radiation-induced CP, severe disease)
  • Haemodynamic improvement may take weeks-months post-surgery
  • Not performed during active inflammation (wait for resolution)

Referral Criteria

• All suspected constrictive pericarditis: specialist cardiology referral
• Confirmation of diagnosis: cardiac MRI ± catheterisation
• Surgical assessment: cardiothoracic surgery for pericardiectomy

• Without pericardiectomy: progressive deterioration and death from right heart failure
• Post-pericardiectomy: ~80% experience significant symptomatic improvement
• Operative mortality: ~5-10% overall; ~15-20% for radiation-induced CP
• 10-year survival post-pericardiectomy: ~60-70%
• Radiation-induced CP: worst surgical outcomes
• Transient constrictive pericarditis (~15%): excellent prognosis with medical therapy
• TB constrictive pericarditis: good outcomes if diagnosed early and treated with anti-TB therapy + pericardiectomy

Constrictive vs Restrictive: Key Differences

Causes of Constrictive Pericarditis