Constrictive Pericarditis
Constrictive pericarditis is often difficult to distinguish from restrictive cardiomyopathies. Multiple imaging modalities, invasive hemodynamic tests, history, and physical examination are often needed to confirm the diagnosis.
Etiology
Idiopathic, viral pericarditis (chronic or recurrent), postcardiotomy, chest irradiation, autoimmune connective tissue disorders, end-stage renal disease, uremia, malignancy (e.g., breast, lung, lymphoma), and tuberculosis (more common in endemic countries).
Pathophysiology
• In the setting of chronic inflammation, the pericardial layers become thickened, scarred, and calcified.
• The pericardial space is obliterated, and the pericardium becomes noncompliant. This impairs ventricular filling and leads to an equalization of pressures in all four chambers and subsequent heart failure symptoms.
DIAGNOSIS
History
The clinical presentation of constrictive pericarditis is insidious, with gradual development of fatigue, exercise intolerance, and venous congestion.
Physical Examination
• Features of right-sided heart failure: lower extremity edema, hepatomegaly, ascites, elevated jugular venous pressure (JVP).
• Other characteristic signs
î Kussmaul sign: paradoxical increase in JVP with inspiration or lack of appropriate decrease in JVP with inspiration.
î Pericardial knock: early, loud, high-pitched S3.
Diagnostic Testing
• TTE
î First-line diagnostic test.
î Ventricular systolic function can be deceptively “normal.”
î Features suggestive of constrictive pericarditis include the following:
■ Increased pericardial thickness/tethering of the pericardium to the myocardium.
■ Dilated, incompressible inferior vena cava (IVC).
■ Septal bounce (exaggerated septal motion).
■ Inspiratory variation in mitral flow velocity curves.
■ Expiratory diastolic flow reversal in hepatic veins.
■ Preserved (or increased) tissue Doppler velocities of the mitral annulus.
■ Blunted superior vena cava flow.
• Cardiac catheterization: allows for simultaneous measurement of right ventricular and left ventricular
pressures.
• Cardiac CT and MRI
î Provide excellent visualization of pericardial anatomy (thickness and calcification).
î An MRI and gated CT can show evidence of ventricular interdependence (septal bounce).
î Can provide other anatomic information that may be helpful in making the diagnosis of constriction
(i.e., engorgement of IVC and hepatic veins) and its etiology (i.e., lymph nodes, tumors).
TREATMENT
• Limited role for medical therapy: diuretics, low-sodium diet.
• Patients with constriction often have a resting sinus tachycardia. Because of limited stroke volume (SV), they are more dependent on heart rate for adequate cardiac output (CO). Avoid efforts to slow down the heart rate.
• Surgical pericardie ctomy is the only definitive treatment for constrictive pericarditis. Operative mortality is 5%-15%; more advanced heart failure symptoms confer higher operative risk.