Constrictive pericarditis

Overview

•Globally: tuberculosis is the most common identifiable cause

•Developed world: idiopathic/viral, cardiac surgery, mediastinal irradiation (5-10 years latency)

•Highest risk of constriction: bacterial (purulent) pericarditis

•Intermediate risk: post-cardiac surgery, systemic inflammatory disease (RA, SLE), mediastinal irradiation, TB

•Low risk: viral/idiopathic, uraemia, drugs, trauma

•Mechanism: pericardial inflammation → fibrosis → thickening → calcification ('eggshell') → rigid shell impairs diastolic filling with fixed cardiac volume

Presentation

•Gradual onset over months - dyspnoea on exertion, fatigue, peripheral oedema, ascites

•Raised JVP with prominent X and Y descents (Friedreich's sign)

•Kussmaul's sign - paradoxical rise in JVP on inspiration; venous return increases but rigid pericardium prevents right heart from accommodating it

•Pericardial knock - high-pitched early diastolic sound, lower left sternal border; earlier and higher-pitched than S3

•Hepatomegaly (up to 70%), reduced/absent apical impulse

•Pulsus paradoxus - uncommon (contrast with cardiac tamponade)

🎯

Classic exam pattern: marked venous congestion (raised JVP, oedema, ascites) + normal heart size on CXR + no valvular disease = constrictive pericarditis until proven otherwise.

Investigations

🥇 First-line

•CXR - normal/small heart size; 'eggshell' pericardial calcification

•Echocardiogram - preserved EF (HFpEF pattern); respirophasic variation in mitral/tricuspid inflow; septal bounce; pericardial thickening

•ECG - non-specific changes; low-voltage QRS if coexisting effusion

•Bloods - BNP/NT-proBNP only mildly elevated (contrast with myocardial failure); CRP/ESR elevated if active inflammation

🏆 Gold standard

•Cardiac MRI - pericardial thickening (>4 mm), gadolinium enhancement (active inflammation), ventricular interdependence; best discriminator from restrictive cardiomyopathy

🥈 Second-line

•CT chest - quantifies pericardial calcification; use if MRI contraindicated

•Cardiac catheterisation - equalisation of diastolic pressures across all four chambers; reserved for inconclusive non-invasive imaging

Differential diagnosis

Constrictive pericarditis vs restrictive cardiomyopathy

Feature	Constrictive pericarditis	Restrictive cardiomyopathy
Pericardial thickening	Yes (>4 mm on MRI)	No
Pericardial calcification	May be present (CXR/CT)	Absent
Respirophasic variation (echo)	Prominent (>25% mitral, >40% tricuspid)	Absent
Septal bounce	Present	Absent
BNP	Mildly elevated	Markedly elevated
Catheterisation	Equalisation of diastolic pressures	RVEDP < LVEDP by >5 mmHg
Treatment	Pericardiectomy (surgical)	Medical (no surgery)

Management

Step 1 · Assess for transient (reversible) constriction

1. 1Features: recent onset, elevated CRP/ESR, gadolinium enhancement on MRI (active inflammation)
2. 2Trial of anti-inflammatory therapy - may resolve over weeks to months, avoiding surgery

↓

Transient constriction

Anti-inflammatory treatment; reassess - pericardiectomy avoided if haemodynamics normalise

Established fibrotic constriction

Pericardiectomy (surgical pericardial stripping) - definitive treatment; best outcomes before severe myocardial atrophy or hepatic fibrosis develop

↓

Supportive · Symptom relief

1. 1Diuretics - relieve oedema/ascites pre-operatively; avoid over-diuresis (ventricles critically dependent on filling pressure)

⚠️

Pericardiectomy must fully excise the pericardium - incomplete excision risks persistent haemodynamic compromise. Surgery should not be delayed until end-stage disease.

Complications

•Progressive right heart failure → cardiac cirrhosis and jaundice

•Protein-losing enteropathy - elevated mesenteric venous pressure

•Atrial fibrillation - chronically elevated atrial pressure

•Cardiac cachexia in advanced untreated disease