Constrictive Pericarditis

Pericardial Fibrosis and Thickening

• Normal pericardium is a thin (0.5–1 mm), double-walled serosal structure with minimal physiologic constraint on cardiac filling
• In constrictive pericarditis, the visceral and parietal pericardium undergo chronic inflammation followed by extensive collagen deposition, fibrosis, and occasionally calcification (visible on imaging in ~25% of cases)
• The thickened pericardium (typically >3 mm on CT imaging) becomes inelastic and creates a fixed restraining boundary around the heart; this rigid shell cannot accommodate normal ventricular expansion during diastole
• Fibrotic transformation reduces pericardial elasticity such that even small increases in ventricular volume produce large increases in intrapericardial pressure, directly restricting filling

Ventricular Interdependence and Equalization of Diastolic Pressures

• The fixed total cardiac volume imposed by the rigid pericardium creates a "zero-sum" relationship: filling of one ventricle during early diastole requires displacement of the other ventricle, increasing interdependence
• Ventricular septal shift becomes exaggerated during respiration; inspiration increases right ventricular filling but paradoxically decreases left ventricular filling due to septal bulging
• Diastolic pressures equilibrate across all cardiac chambers (left ventricular end-diastolic pressure [LVEDP], right ventricular end-diastolic pressure [RVEDP], and right atrial pressure [RAP] typically within 5 mmHg of each other), a hallmark hemodynamic finding
• This pressure equalization occurs because the pericardial restraint becomes the limiting factor for filling rather than ventricular compliance

Impaired Diastolic Function with Preserved Systolic Function

• The pericardial restriction selectively impairs ventricular filling (diastolic dysfunction) while leaving systolic contractile function largely intact; ejection fraction remains normal or near-normal (distinguishing from restrictive cardiomyopathy where systolic function may be mildly reduced)
• Early rapid filling (early diastole) is abruptly halted by the pericardial restraint, creating the pathognomonic square root sign on ventricular pressure tracings (rapid initial pressure drop followed by a plateau during diastasis)
• Atrial pressure rises dramatically as ventricular filling becomes restricted, leading to elevated jugular venous pressure (JVP), hepatomegaly, and edema
• Stroke volume becomes fixed and cannot increase normally with increased preload or during exercise, severely limiting cardiac output augmentation

Respiratory Variation and Pulsus Paradoxus

• Because of enhanced ventricular interdependence and the fixed total cardiac volume, inspiration causes preferential right ventricular filling, further compressing the left ventricle and reducing left ventricular stroke volume
• This leads to an exaggerated drop in systolic blood pressure during inspiration (pulsus paradoxus >10 mmHg), reflecting the inability of the constrained pericardium to allow compensatory expansion
• The septal shift increases systolic wall stress on the left ventricle, compounding the hemodynamic compromise

Elevated Venous Pressures and Hepatic Congestion

• Right atrial pressure elevation (typically 10–20 mmHg) leads to elevated JVP with prominent x (early diastolic) and y (early filling) descents; the y descent may be particularly prominent ("steep y descent") reflecting rapid early filling before hitting the pericardial constraint
• Hepatic congestion results from sustained elevated systemic venous pressure, causing hepatomegaly and eventually hepatic cirrhosis if chronic
• Pulmonary congestion may be relatively mild initially because of fluid redistribution to the systemic venous system, but can occur with progression

Infectious Causes

• Tuberculosis is the most common cause of constrictive pericarditis globally and the leading cause in endemic regions; tuberculous pericarditis progresses to constriction in 30–50% of untreated cases and in ~10% despite appropriate anti-tuberculous therapy; typically develops during active disease or shortly after
• Bacterial pericarditis (from Streptococcus aureus, gram-negative organisms, or Streptococcus pneumoniae) can progress to constriction, though less commonly than tuberculosis
• Viral pericarditis (coxsackievirus, adenovirus, parvovirus B19, cytomegalovirus, HIV) occasionally progresses to constriction, usually in immunocompromised hosts
• Fungal pericarditis (histoplasmosis, coccidioidomycosis, blastomycosis, cryptococcosis) can develop into constriction, particularly in endemic regions or immunocompromised patients

Post-Cardiac Surgery and Trauma

• Post-cardiac surgery is now the most common etiology in developed nations; occurs in 0.2–2% of cardiac surgery patients months to years after coronary artery bypass grafting, valve replacement, or other procedures
• Post-traumatic constriction can develop after blunt or penetrating chest trauma, even without recognized pericardial injury
• Post-myocardial infarction pericarditis rarely progresses to constriction

Malignancy-Related

• Metastatic pericardial involvement from lung, breast, melanoma, or lymphoma can cause constrictive physiology
• Radiation pericarditis from mediastinal radiation (for thoracic malignancy, breast cancer, or lymphoma) causes delayed fibrosis and constriction, typically 5–10 years post-radiation
• Chemotherapy-related constriction (anthracycline cardiotoxicity) is less common but recognized

Idiopathic/Collagen Vascular Disease

• Idiopathic constrictive pericarditis represents 20–30% of cases in developed nations; etiology remains unknown despite extensive evaluation
• Systemic lupus erythematosus (SLE), rheumatoid arthritis, and systemic sclerosis can cause pericardial fibrosis and constriction
• Post-pericardiotomy syndrome (post-pericardial surgery effusion or inflammation) rarely progresses to constriction

Other Causes

• Chronic renal failure with uremic pericarditis; constriction is rare but can occur with inadequate dialysis
• Asbestos exposure causing pericardial mesothelioma and fibrosis
• Liver cirrhosis with hepatic hydrothorax and pericardial involvement
• Dressler's syndrome (post-myocardial infarction autoimmune pericarditis) rarely causes constriction
• History of pericardial effusion with tamponade requiring drainage

Cardinal Symptoms

• Dyspnea on exertion is the most common presenting symptom, occurring because cardiac output cannot increase appropriately during activity due to the fixed stroke volume imposed by pericardial restraint; patients typically describe progressive exertional dyspnea with normal resting function
• Peripheral edema and ascites reflect elevated systemic venous pressure; edema may be prominent and symmetric, often involving lower extremities and presacral regions in bedridden patients
• Abdominal distension and discomfort from hepatomegaly and ascites; some patients present with abdominal symptoms that dominate the clinical picture
• Fatigue and decreased exercise tolerance reflect reduced cardiac output; patients may note inability to perform activities previously tolerated
• Orthopnea and paroxysmal nocturnal dyspnea (PND) occur less prominently than in systolic heart failure but can occur with pulmonary congestion in advanced disease
• Syncope or presyncope may occur with exertion if cardiac output drops critically; can be a presenting symptom in advanced constriction

Physical Examination Findings

• Elevated jugular venous pressure (JVP) is the most important and consistent finding; typically 10–20 cmH₂O; prominent x descent (rapid early systolic collapse reflecting ventricular systole) and prominent y descent (rapid early diastolic collapse reflecting the initial rapid filling phase abruptly halted by pericardial restraint); the y descent may be particularly sharp ("steep y descent"), creating an M or W appearance (sometimes called an "M" or "W" sign in the JVP waveform)
• Hepatomegaly is present in >80% of cases; the liver is palpable, often firm, and may be pulsatile (prominent hepatic pulsation reflecting constrictive physiology)
• Pulsus paradoxus is an exaggerated drop in systolic blood pressure during inspiration (>10 mmHg); measured as the difference between the systolic pressure when Korotkoff sounds are first heard during expiration versus when heard throughout the respiratory cycle; reflects the exaggerated septal shift and left ventricular compression during inspiration
• Peripheral edema and ascites with dependent distribution
• Diminished or distant heart sounds from pericardial thickening
• Third heart sound (S₃ gallop) may be present but is not prominent; some sources describe a "pericardial knock" (early diastolic sound coinciding with the abrupt halt of ventricular filling), though this is less reliable than in restrictive cardiomyopathy
• Atrial fibrillation is common, either from chronic elevation of atrial pressure or underlying etiology
• Reduced cardiac output signs: cool extremities, narrow pulse pressure, oliguria in advanced disease
• Kussmaul sign: paradoxical rise in JVP with inspiration (normally JVP falls with inspiration); occurs because the right atrium is already maximally compressed by the pericardium and cannot accommodate the normal increase in venous return during inspiration, so venous pressure rises instead

Clinical Variants and Atypical Presentations

• Transient constrictive pericarditis: Some patients present with reversible constriction-like physiology from acute or subacute pericarditis that resolves without progression; hemodynamic normalization can occur with anti-inflammatory therapy over weeks to months
• Occult constriction: Patients may have hemodynamic findings only during exercise or fluid loading (diagnostic catheterization during saline infusion or leg raise may provoke equalization of diastolic pressures)
• Effusive-constrictive pericarditis: Constriction coexists with pericardial effusion; hemodynamic constraint persists despite effusion drainage
• Early constriction: Mild elevation of venous pressure without marked ascites or edema; may be detected incidentally on cardiac imaging

Clinical Suspicion and History

• High index of suspicion should be triggered by: progressive exertional dyspnea, elevated JVP with x and y descents, hepatomegaly with ascites, and pulsus paradoxus in a patient with risk factors (prior cardiac surgery, tuberculosis exposure, radiation, malignancy)
• History of preceding pericarditis, pericardial effusion/tamponade, cardiac surgery, or mediastinal radiation significantly increases pre-test probability

Physical Examination Pearls

• The triad of findings most suggestive of constriction: elevated JVP with prominent x and y descents + hepatomegaly + pulsus paradoxus
• Kussmaul sign (paradoxical JVP rise with inspiration) is highly specific for constrictive physiology but present in only 20–30% of patients
• Careful measurement of pulsus paradoxus using blood pressure cuff or arterial line; presence confirms abnormal ventricular interdependence

Electrocardiography (ECG)

• Often abnormal but non-specific; common findings include atrial fibrillation (present in 30–50%), low voltage (reflecting pericardial thickening), T wave inversion, and prolonged PR interval
• Absence of abnormalities does not exclude constriction
• Sensitivity ~60–70%, specificity modest; used to support diagnosis but not diagnostic alone

Chest X-ray

• Cardiomegaly may be absent (reflecting normal cardiac size despite elevated diastolic pressures), distinguishing from dilated cardiomyopathy
• Pericardial calcification visible in ~25–30% of cases (more common in post-tuberculosis and post-traumatic constriction); highly specific when present but insensitive
• Pleural effusions (usually right-sided) may be present
• Pulmonary edema typically mild, supporting diagnosis over systolic heart failure

Echocardiography

• Pericardial thickening: Normally pericardium is barely visualized; thickening >3 mm on 2D echo or >4 mm on 3D echo is abnormal and suggestive of constriction, though absence of thickening does not exclude diagnosis (sensitivity ~60%, specificity ~80–90%)
• Septal bounce: Exaggerated early diastolic leftward motion of interventricular septum reflects the rapid early filling followed by abrupt deceleration; characteristic but not present in all cases
• Restrictive mitral inflow pattern: Early diastolic filling wave (E wave) is elevated with rapid deceleration; E/A ratio >1; deceleration time <150 msec; annular tissue Doppler (e') velocity often normal (e' >8 cm/s), distinguishing from restrictive cardiomyopathy where e' is reduced
• Reduced annular e' velocity in restrictive cardiomyopathy (typically <8 cm/s) helps differentiate; constrictive pericarditis usually preserves e' velocity
• Hepatic vein flow: Prominent hepatic vein diastolic reversal with inspiration reflects elevated right atrial pressure and constrictive physiology
• Strain imaging may show regional or global dysfunction
• Limited sensitivity for definitively excluding constriction but helpful for identifying pericardial thickening and assessing diastolic mechanics

Cardiac Computed Tomography (CT)

• Superior imaging modality for pericardial morphology: directly visualizes pericardial thickening (>3 mm), calcification, and loculation
• High sensitivity (90–95%) and specificity (>90%) for detecting thickening
• Excellent for excluding other diagnoses (pericardial cyst, effusion, malignant involvement)
• Limitations: radiation exposure, iodine contrast requirement, cannot assess hemodynamics or functional consequences
• Findings: homogeneous thickened pericardium (may be circumferential or loculated), calcification, and sometimes pericardial fat stranding

Cardiac Magnetic Resonance (CMR)

• Excellent visualization of pericardial morphology and tissue characterization (T1 and T2 mapping can assess inflammation vs fibrosis)
• Can assess ventricular function and quantify septal curvature
• May identify late gadolinium enhancement indicating fibrosis or pericardial enhancement with inflammation
• Useful for evaluating for restrictive cardiomyopathy (myocardial involvement) vs constriction
• Limitations: contraindicated with certain devices, longer acquisition time, less available than CT

• Invasive but provides definitive hemodynamic confirmation; indicated when clinical and imaging findings suggest constriction

Initial stabilisation and symptom control

• Loop diuretics (e.g., furosemide) plus dietary sodium restriction: relieve hepatic congestion, ascites, and edema. Because stroke volume is fixed by the pericardial shell, filling pressures must stay high to drive any output — over-diuresis produces hypotension and pre-renal azotemia. Titrate to symptom relief, not to a "normal" JVP.
• Mineralocorticoid receptor antagonists (e.g., spironolactone): useful adjunct for refractory ascites and secondary hyperaldosteronism from hepatic congestion.
• Avoid negative chronotropes: beta blockers and non-dihydropyridine calcium channel blockers are relatively contraindicated, since cardiac output is rate-dependent when stroke volume cannot rise. Reserve them for rate control of poorly tolerated atrial fibrillation.

Treat the underlying cause

• Antituberculous therapy for tuberculous pericarditis: standard four-drug regimen (rifampin, isoniazid, pyrazinamide, ethambutol) per the ATS/CDC/IDSA treatment guideline; early therapy reduces, but does not eliminate, progression to constriction.
• Anti-inflammatory therapy for suspected transient/inflammatory constriction: ESC supports a 2–3 month empiric trial of NSAID or aspirin plus colchicine, with corticosteroids in selected cases, when CRP is elevated or CMR shows pericardial edema/late gadolinium enhancement. Some patients resolve without surgery.

Definitive management

• Complete (radical) pericardiectomy via median sternotomy is the only definitive therapy for chronic, permanent constriction and is recommended by ESC for persistent NYHA III–IV symptoms. Refer early — outcomes deteriorate once cachexia, hyperbilirubinemia, renal dysfunction, or atrial fibrillation develop.
• Incomplete decortication predicts persistent constriction; the goal is circumferential release over both ventricles.

When surgery should be withheld

• Radiation-induced constriction with myocardial fibrosis/atrophy, severe mixed restrictive cardiomyopathy, end-stage hepatic or renal failure, or occult constriction without symptoms — perioperative mortality is high and benefit minimal. Medical palliation is preferred.

Complications of untreated constriction

• Cardiac cirrhosis ("cardiac sclerosis"): chronic sinusoidal congestion from sustained high right atrial pressure causes centrilobular fibrosis. Signalled by firm hepatomegaly, hyperbilirubinemia, prolonged INR, and refractory ascites; a high serum–ascites albumin gradient with high total protein points to a cardiac rather than cirrhotic source.
• Protein-losing enteropathy: intestinal lymphatic and venous congestion causes enteric albumin loss — unexplained hypoalbuminemia with edema out of proportion to renal or hepatic disease. Confirmed by elevated stool alpha-1 antitrypsin clearance.
• Cardiac cachexia: congestive gut malabsorption plus neurohormonal catabolism; predicts poor surgical outcome.
• Atrial fibrillation and atrial thrombus: chronic atrial pressure overload and stretch cause electrical remodeling; sudden decompensation with loss of the (already limited) atrial contribution to filling. Manage stroke risk per the ACC/AHA/HRS atrial fibrillation guideline.
• Cardiorenal syndrome: renal venous congestion plus low output → rising creatinine with bland urine; often worsened by aggressive diuresis.
• Fixed low-output state with exertional syncope — an ominous sign warranting urgent surgical referral.
• Effusive-constrictive physiology: constriction persists after effusion drainage; if the effusion component causes tamponade, this is an emergency requiring pericardiocentesis.

Complications of therapy

• Over-diuresis: preload dependence means volume depletion produces abrupt hypotension, syncope, and acute kidney injury — the classic pitfall.
• Post-pericardiectomy low cardiac output syndrome: an emergency. After decortication, chronically unloaded, atrophic myocardium cannot handle restored filling volumes; presents within hours as hypotension with rising filling pressures and requires inotropes and sometimes mechanical support.
• Acute pulmonary edema after release from a sudden rise in right ventricular output into an unprepared left heart.
• Surgical injury: myocardial or coronary laceration with hemorrhage (emergency), phrenic nerve injury, arrhythmias, and bleeding from a calcified, adherent pericardium.
• Persistent or recurrent constriction from incomplete decortication or ongoing inflammation — unchanged JVP and septal bounce postoperatively.

• Kussmaul sign (JVP rises with inspiration) and a pericardial knock (early diastolic, higher-pitched than an S₃) are the two examination buzzwords; on the venous waveform the y descent is prominent and steep, whereas in tamponade it is blunted or absent. Examiners use this y-descent contrast to separate the two.
• Pericardial calcification on lateral chest radiograph in a patient with ascites and a normal ejection fraction is a near-giveaway — think prior tuberculosis (worldwide) or prior cardiac surgery/mediastinal radiation (United States).
• Single best next step in suspected constriction: transthoracic echocardiography (septal bounce, respirophasic septal shift, hepatic vein expiratory diastolic flow reversal), then CT/CMR for pericardial thickness and inflammation, with right and left heart catheterization reserved for equivocal cases.
• The catheterization findings tested are the dip-and-plateau / square root sign, equalization of end-diastolic pressures, and discordance of RV and LV systolic pressures with respiration — the most specific invasive discriminator from restrictive cardiomyopathy.
• Constriction vs restrictive cardiomyopathy: mitral annular e′ is preserved or increased in constriction (annulus paradoxus, and annulus reversus with lateral e′ lower than septal e′) but reduced in restriction; BNP tends to be far higher in restrictive cardiomyopathy. Amyloidosis is the association to know on the restrictive side.
• Definitive therapy is complete pericardiectomy, not diuretics — per the 2015 ESC pericardial disease guideline. Diuretics palliate only, and over-diuresis crashes a preload-dependent patient.
• Do not blunt the heart rate: with a fixed stroke volume, output is rate-dependent, so beta blockers and verapamil/diltiazem are avoided.
• Common distractor: attributing ascites plus hepatomegaly to cirrhosis. Cirrhosis has a normal or low JVP; elevated JVP with ascites points to the pericardium (or right heart).