Constrictive pericarditis

Prolonged or chronic inflammation of the pericardial bag - the outer connective tissue sheath surrounding the heart, accompanied by fibrous thickening and loss of elasticity of its tissues, is defined as compressive or constrictive pericarditis (from Latin constrictio - constriction, squeezing). [1]

Epidemiology

The exact prevalence of this condition is unknown, but compressive pericarditis is seen in 0.4% of cases after cardiac surgery, 37% of cases after thoracic surgery, and 7-20% of cases after thoracic radiation therapy. [2]

Idiopathic compressive pericardial inflammation has been reported to account for up to 46% of cases.

In developing countries, post-tuberculous constrictive pericarditis is estimated in 20-80% of cases. [3]

Causes of the constrictive pericarditis

Specialists note such possible causes of compressive inflammation of the outer lining of the heart and its focal or extensive fibrous thickening, [4], [5], [6] as:

• undergone cardiac surgery;
• Radiation therapy of oncologic diseases of thoracic organs and breast cancer;
• tuberculosis;
• pericarditis of viral and bacterial etiology;
• Cardiac tumors, including mesothelioma.

In some cases, doctors cannot find the cause of inflammation, and then constrictive pericarditis is considered idiopathic.

Also see:

• What causes pericarditis?
• Pericarditis: general information

Risk factors

The following factors increase the risk of developing this condition:

• chest trauma or damage to the heart (e.g. Due to acute myocardial infarction);
• A history of autoimmune diseases, primarily systemic lupus erythematosus, rheumatoid arthritis, systemic vasculitis and Kawasaki disease, Wegener's granulomatosis;
• severe renal failure with uremia;

Long-term use of such antiarrhythmic drugs as Procainamide, the drug Hydralazine (used to lower BP), the antiserotonin drug Methysergide (Methylmetergine, Deseril), prolactin-lowering Cabergoline (Alactin, Dostinex) and others.

Pathogenesis

Surrounding the heart pericardium is a structure consisting of an outer fibrous layer and an inner serous layer. The fibrous layer is formed by connective tissue represented by collagen (types I and III) and elastin fibers. The inner serous pericardium is divided into the visceral layer (which helps minimize friction) and the parietal layer (which provides additional protection to the heart). [7]

Studying the pathogenesis of constrictive pericarditis, the researchers concluded that oxidative stress, hypoxia and microvascular damage, as well as neoplastic infiltration of the pericardium lead to fibrosis of the pericardial tissue - deposition of collagen and fibrin in the form of scars, as well as abnormal changes in the structure of the interstitial extracellular matrix. This involves both activation of TGF-β1 (transforming growth factor beta 1), which provokes the transformation of fibroblasts and other cell types into myofibroblasts, and autocrine induction of the cytokine CTGF (connective tissue growth factor). [8], [9]

As a result, there is fibrous thickening and even calcification (calcification) of the pericardium, which leads to impaired elasticity of the pericardial sac.

Pericardial insufficiency develops with increased diastolic pressure in all chambers of the heart, more rapid increase in ventricular pressure, restricted ventricular relaxation of the heart, and decreased cardiac output in response to exercise. [10]

Symptoms of the constrictive pericarditis

Over a long period of time, the first signs of constrictive pericarditis may be manifested by progressive dyspnea.

At a later stage, other symptoms appear, including:

• weakness and increased fatigue;
• an angina-like feeling of tightness in the heart area;
• chest pains and pain under the shoulder blade;
• heart rhythm irregularities (increased heart rate at rest and on exertion) and muffled heart tones;
• swelling of the face, constant swelling of the legs in the area of ankles and feet;
• lividity of the fingers (acrocyanosis);
• dilation of skin capillaries in the form of telangiectasia (vascular asterisks);
• swelling of the anterior jugular vein (in the neck) during inhalation - due to a paradoxical rise in venous pressure (so-called Kussmaul's symptom).

Progression of the disease leads to the development of ascites.

Read also - Chronic pericarditis

A distinction is made between types such as:

• Chronic constrictive pericarditis, in which the heart is compressed by thickened parietal and visceral layers of pericardium, resulting in persistent elevation of diastolic pressure in both ventricles of the heart, chronic venous stasis and decreased minute blood flow, and sodium and fluid retention;
• Subacute constrictive pericarditis or subacute effusion-constrictive pericarditis with associated tense pericardial effusion, in which cardiac compression and persistent pressure increase in the right atrium is due to the visceral layer of the pericardial sac;
• transient or transient constrictive pericarditis, which is idiopathic in most cases but is presumably related to underlying viral or bacterial inflammation of the pericardium. Symptoms of heart failure due to restricted diastolic filling of the left and right ventricles of the heart, may disappear within about three months.

Complications and consequences

Complications and consequences of constrictive pericarditis include the development of severe chronic heart failure in the form of cardiac cachexia.

Mechanical compression of the heart with decreased minute blood flow (cardiac output), referred to as cardiac tamponade, is also possible.

Diagnostics of the constrictive pericarditis

Read more - Diagnosing pericarditis

Patients undergo auscultation of the heart and palpation of the precardiac region. Laboratory studies include general and biochemical blood tests, tests for autoantibodies.

Instrumental diagnosis is mandatory, using instrumental methods of cardiac research, including ECG; X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) of the chest and heart; and transthoracic Doppler echocardiography (echoCG).

CT and MRI imaging provide detailed images of the heart and its outer lining and reveal pericardial thickening.

Echocardiographic signs of constrictive pericarditis are noted in the form of thickening of the pericardium, enlargement of the atria, limitation of the ventricular volume of the heart, decreased respiratory fluctuations with dilated veins (inferior vena cava and hepatic), abnormal movement of the interventricular septum between beats - at the beginning of relaxation of the heart muscle (diastole). [11]

Differential diagnosis

Differential diagnosis is made with pneumonia and pleurisy, intercostal neuralgia and myofascial syndrome, osteochondrosis of the thoracic spine, angina pectoris and myocarditis, restrictive and dilated cardiomyopathy.

Treatment of the constrictive pericarditis

Treatment of pericarditis, accompanied by fibrous thickening and loss of elasticity of the outer lining of the heart, is aimed at improving its function.

In the early stages, loop diuretics are prescribed but should be used with caution as any reduction in intravascular volume may result in a significant reduction in cardiac output. Some patients may be advised strict fluid restriction and a low-salt diet; non-steroidal anti-inflammatory drugs (Ibuprofen, etc.) are administered, and systemic corticosteroids may be prescribed. [12]

Any other drug treatment should be directed at the etiology of the disease, such as anti-tuberculosis therapy. [13]

In severe chronic constrictive pericarditis, surgical treatment is performed - pericardectomy, i.e. Removal of visceral and parietal pericardium, after which hemodynamic disorders disappear in almost 60% of patients. However, such surgical treatment is contraindicated in cases of severe pericardial calcification, fibrosis and myocardial dysfunction, post-radiation pericarditis and severe renal dysfunction.

Prevention

Constrictive pericarditis can develop without an obvious underlying cause, and in some cases it cannot be prevented. However, prevention of tuberculosis and myocardial infarction is possible.

Forecast

The long-term prognosis of constrictive pericarditis depends on the cause of its development, and with timely treatment, long-term maintenance of cardiac function is possible.

Surgical intervention in the form of pericardectomy is fatal in about 12-15% of cases.