In many cases, constrictive pericarditis is a late sequela, in other words a condition that is the consequence of a previous disease, of an inflammatory condition of the pericardium

Pericardium

The pericardium is a double-walled sac that contains the heart and the roots of the great vessels.-Layers:...

. The inflammatory condition is usually an infection that involves the pericardium, but it may also occur after a heart attack

Myocardial infarction

Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...

 or after heart surgery

Coronary artery bypass surgery

Coronary artery bypass surgery, also coronary artery bypass graft surgery, and colloquially heart bypass or bypass surgery is a surgical procedure performed to relieve angina and reduce the risk of death from coronary artery disease...

.

Causes

Almost half the cases of constrictive pericarditis in the developing world are idiopathic in origin. In regions where tuberculosis

Tuberculosis

Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...

 is common, it is the cause in a large portion of cases.

Causes of constrictive pericarditis include:

• Infectious:
  • Tuberculosis
    Tuberculosis
    Tuberculosis, MTB, or TB is a common, and in many cases lethal, infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis usually attacks the lungs but can also affect other parts of the body...
    
    
  • Incomplete drainage of purulent pericarditis
    Pericarditis
    Pericarditis is an inflammation of the pericardium . A characteristic chest pain is often present.The causes of pericarditis are varied, including viral infections of the pericardium, idiopathic causes, uremic pericarditis, bacterial infections of the precardium Pericarditis is an inflammation of...
    
    
  • Fungal and parasitic infection
    Infection
    An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
    
    s
• Inflammatory and autoimmune
  • Chronic pericarditis
  • Postviral pericarditis
    Pericarditis
    Pericarditis is an inflammation of the pericardium . A characteristic chest pain is often present.The causes of pericarditis are varied, including viral infections of the pericardium, idiopathic causes, uremic pericarditis, bacterial infections of the precardium Pericarditis is an inflammation of...
    
    
  • Postsurgical
  • Following pericarditis
    Pericarditis
    Pericarditis is an inflammation of the pericardium . A characteristic chest pain is often present.The causes of pericarditis are varied, including viral infections of the pericardium, idiopathic causes, uremic pericarditis, bacterial infections of the precardium Pericarditis is an inflammation of...
    
     associated with acute myocardial infarction
  • Following post-myocardial infarction (Dressler's) syndrome
    Dressler's syndrome
    Dressler's syndrome is a secondary form of pericarditis that occurs in the setting of injury to the heart or the pericardium...
    
    
  • In association with pulmonary asbestosis
    Asbestosis
    Asbestosis is a chronic inflammatory and fibrotic medical condition affecting the parenchymal tissue of the lungs caused by the inhalation and retention of asbestos fibers...
    
    
• Prior mediastinal radiation therapy
  Radiation therapy
  Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...
  
  
• Chronic renal failure
  Chronic renal failure
  Chronic kidney disease , also known as chronic renal disease, is a progressive loss in renal function over a period of months or years. The symptoms of worsening kidney function are unspecific, and might include feeling generally unwell and experiencing a reduced appetite...
  
  
• Connective tissue disorders
• Neoplastic pericardial infiltration

Pathophysiology

Constrictive pericarditis is due to a thickened, fibrotic pericardium that forms a non-compliant shell around the heart. This shell prevents the heart from expanding when blood enters it. This results in significant respiratory variation in blood flow in the chambers of the heart.

During inspiration, the negative pressure in the thoracic cavity

Thoracic cavity

The thoracic cavity is the chamber of the human body that is protected by the thoracic wall ....

 will cause increased blood flow into the right ventricle. This increased volume in the right ventricle will cause the interventricular septum to bulge towards the left ventricle, leading to decreased filling of the left ventricle. Due to the Frank–Starling law, this will cause decreased pressure generated by the left ventricle during systole

Systole (medicine)

Systole is the contraction of the heart. Used alone, it usually means the contraction of the left ventricle.In all mammals, the heart has 4 chambers. The left and right ventricles pump together. The atria and ventricles pump in sequence...

.

During expiration, the amount of blood entering the right ventricle will decrease, allowing the interventricular septum to bulge towards the right ventricle, and increased filling of the left ventricle and subsequent increased pressure generated by the left ventricle during systole.

This is known as ventricular interdependence, since the amount of blood flow into one ventricle is dependent on the amount of blood flow into the other ventricle.

Diagnosis

The diagnosis of constrictive pericarditis is often difficult to make. In particular, restrictive cardiomyopathy

Restrictive cardiomyopathy

Restrictive cardiomyopathy is a form of cardiomyopathy in which the walls are rigid, and the heart is restricted from stretching and filling with blood properly....

 has many similar clinical features to constrictive pericarditis, and differentiating them in a particular individual is often a diagnostic dilemma.

• Imaging will demonstrate a thickened pericardium and you will see an increased early diastolic filling with reduced filling in mid-diastole. While with restrictive cardiomyopathy you have an increased resistance to ventricular filling due to increased myocardial stiffness. Imaging features of restrictive cardiomyopathy demonstrate an increased left ventricular thickness with infiltration of the myocardium.

• Chest X-Ray - pericardial calcification (common but not specific), pleural effusions are common findings.

• Echocardiography - demonstrates reduced end-diastolic volumes and elevated diastolic pressures.

• CT and MRI - useful in select cases.

• BNP Blood Test - (FDA approved in 2002) tests for the existence of the cardiac hormone B-Type Natriuretic Peptide which is only present in RCMP but not in CP, and is particularly helpful in determining the specific CHF type.

• Clinical features -

• Kussmaul's sign (raised JVP on inspiration)
• increased JVP (almost universal), rapid descent (prominent diastolic collapse of JVP)
• pericardial knock in around 50% cases
• hepatomegaly and other signs of right heart failure; ascites; fatigue; peripheral edema

Treatment

The definitive treatment for constrictive pericarditis is pericardial stripping, which is a surgical procedure where the entire pericardium is peeled away from the heart. This procedure has significant risk involved, with mortality rates of 6% or higher in major referral centers. The high risk of the procedure is attributed to adherence of the thickened pericardium to the myocardium and coronary arteries. In patients who have undergone coronary artery bypass surgery

Coronary artery bypass surgery

Coronary artery bypass surgery, also coronary artery bypass graft surgery, and colloquially heart bypass or bypass surgery is a surgical procedure performed to relieve angina and reduce the risk of death from coronary artery disease...

with pericardial sparing, there is danger of tearing a bypass graft while removing the pericardium.

If any pericardium is not removed, it is possible for bands of pericardium to cause localized constriction which may cause symptoms and signs consistent with constriction.

Due to the significant risks involved with pericardial stripping, many patients are treated medically, with judicious use of diuretics.