Constrictive Pericarditis Vs Restrictive Cardiomyopathy

 

Constrictive Pericarditis (CP) vs Restrictive Cardiomyopathy (RCM)

Why this distinction matters

Both conditions present with right-sided heart failure, preserved or mildly reduced EF, normal or small ventricles, and elevated filling pressures. However, management and prognosis differ dramatically:

Constrictive pericarditis is potentially curable with pericardiectomy.

Restrictive cardiomyopathy is a myocardial disease, usually managed medically or with transplant consideration.

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Definitions and Core Pathophysiology

Constrictive Pericarditis

Disease of the pericardium

Thickened, fibrotic, often calcified pericardium

Creates a non-compliant shell around the heart

Ventricular interaction and dissociation between intrathoracic and intracardiac pressures

Diastolic filling abruptly stops after early rapid filling

Restrictive Cardiomyopathy

Disease of the myocardium

Ventricular walls are stiff but not necessarily thick

Impaired ventricular relaxation and compliance

Intrathoracic pressure changes are normally transmitted to cardiac chambers

No pericardial constraint

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Etiology

Constrictive Pericarditis

Idiopathic or post-viral (most common worldwide)

Tuberculosis (still important in South Asia)

Post-cardiac surgery

Post-radiation therapy

Chronic pericarditis

Connective tissue diseases

Restrictive Cardiomyopathy

Infiltrative: Amyloidosis (most common), sarcoidosis

Storage diseases: Hemochromatosis, Fabry disease

Endomyocardial fibrosis

Post-radiation myocardial fibrosis

Idiopathic

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Clinical Features (Often Similar)

Feature CP RCM

Dyspnea Yes Yes

Peripheral edema Prominent Prominent

Ascites Common Common

JVP Elevated with rapid y descent Elevated, less prominent y descent

Kussmaul sign Common Can occur

Chest pain Rare Rare

Clinical examination alone is insufficient → imaging and hemodynamics are essential.

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Echocardiography: The Most Important Non-Invasive Tool

Key Echo Findings in Constrictive Pericarditis

Septal bounce (early diastolic interventricular septal shift)

Marked respiratory variation:

Mitral E velocity ↓ ≥25% with inspiration

Tricuspid E velocity ↑ ≥40% with inspiration

Annulus paradoxus:

Medial e′ ≥ lateral e′

Preserved or exaggerated e′ velocities (myocardium is normal)

Dilated IVC with reduced collapse

Key Echo Findings in Restrictive Cardiomyopathy

No septal bounce

Minimal respiratory variation in mitral/tricuspid inflow

Reduced e′ velocities (impaired myocardium)

Biatrial enlargement (often massive)

Restrictive filling pattern (E/A > 2, short DT)

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Tissue Doppler: The Decisive Clue

Parameter CP RCM

Medial e′ Normal or high (>8 cm/s) Reduced

Lateral e′ Reduced Reduced

Medial > Lateral Yes (annulus reversus) No

E/e′ Often normal Elevated

Normal or high e′ strongly favors constriction.

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Cardiac MRI and CT

Constrictive Pericarditis

Pericardial thickness >4 mm

Pericardial calcification (best seen on CT)

Septal bounce on cine MRI

Lack of myocardial fibrosis

Restrictive Cardiomyopathy

Normal pericardium

Diffuse or focal myocardial late gadolinium enhancement

T1 mapping abnormalities (especially amyloidosis)

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Cardiac Catheterization: Gold Standard When Doubt Persists

Hemodynamic Feature CP RCM

LV/RV diastolic pressures Equalized Elevated but not equal

Square root sign Present Present

Respiratory discordance Yes (LV ↓, RV ↑ with inspiration) No

Intrathoracic pressure transmission Absent Preserved

Respiratory discordance of LV and RV pressures is diagnostic of CP.

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Laboratory Clues

BNP: Normal or mildly elevated in CP

BNP: Markedly elevated in RCM (Pericardial constraint limits wall stress in CP)

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Management

Constrictive Pericarditis

Diuretics for symptom control

Treat underlying cause (e.g., TB therapy)

Definitive treatment: Complete pericardiectomy

Excellent outcomes if diagnosed early and myocardium is normal

Restrictive Cardiomyopathy

Diuretics (carefully)

Treat underlying etiology (e.g., amyloidosis-specific therapy)

Rate control in AF

Anticoagulation if AF or atrial enlargement

Advanced cases → heart transplantation

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Prognosis

Condition Prognosis

CP Potentially curable

RCM Progressive, often poor

Early differentiation prevents missed surgical cure or unnecessary surgery.

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One-Glance Comparison Table

Feature Constrictive Pericarditis Restrictive Cardiomyopathy

Primary pathology Pericardium Myocardium

Pericardial thickness Increased Normal

Septal bounce Present Absent

Respiratory variation Marked Minimal

Tissue Doppler e′ Normal/high Reduced

BNP Low–normal High

Surgical cure Yes No

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Key Take-Home Messages

Think pericardium vs myocardium

Normal e′ excludes restrictive cardiomyopathy

Respiratory discordance = constriction

Missing CP means missing a cure