What is pericarditis? The causes are these

Pericarditis is a common disease in daily life and is often divided into many types due to different causes. So what exactly is pericarditis? Most patients are not very aware of this. In fact, pericarditis is an inflammatory lesion of the visceral and parietal layers of the pericardium, and is often part of a systemic disease.

What is pericarditis

Pericarditis is an inflammatory lesion of the visceral and parietal layers of the pericardium. It is often part of a systemic disease and can also be caused by the spread of inflammation or damage to adjacent tissues such as the pleura, myocardium, mediastinum, and lymph nodes. According to the clinical course, it can be divided into three categories: acute, subacute and chronic constrictive pericarditis. The course of the disease is acute within 6 weeks, subacute within half a year, and chronic if it exceeds half a year. Acute cases are often accompanied by effusion, and chronic cases are prone to pericardial constriction.

Causes

1. Infectivity

(1) Tuberculosis is more common in children and young people, and is often spread directly from pulmonary tuberculosis, mediastinal lymph node tuberculosis and pleural tuberculosis, or spread from the blood or lymph. But in some cases no tuberculosis lesions can be found.

(ii) Purulent disease often results from sepsis or septicemia, bacterial invasion of the pericardium through the blood or lymph, or direct spread of purulent inflammation from adjacent tissues such as the lungs, pleura, and mediastinum. Pleural surgery, trauma or esophageal foreign bodies penetrating into the pericardium can also lead to secondary infection. The most common pathogenic bacteria is Staphylococcus aureus, and others such as Pneumococcus, hemolytic Streptococcus, Escherichia coli, Pseudomonas aeruginosa, etc. can also cause disease.

(III) Viral infections include Coxsackievirus, influenza virus (type A and B), and echovirus. In recent years, it has been suggested that some cases of nonspecific pericarditis may be caused by viral infection.

(IV) Fungal infections are more common with capsular histoplasma, which often occur secondary to infection of adjacent lung or hilar lymph nodes and rarely spread through the bloodstream. In addition, it is also caused by actinomycetes, Candida, and Escherichia.

(V) Left lobe liver abscess caused by parasitic amoeba often penetrates into the pericardium and causes acute pericarditis. In addition, infections such as microfilaria, schistosomiasis, and toxoplasmosis may occasionally be seen.

2. Non-infectious

(1) Acute nonspecific pericarditis is very common abroad and is also increasing in China. The cause may be related to viral infection, and it is also believed to be a manifestation of allergy or autoimmune reaction. The onset is usually acute, and about half of the patients have an upper respiratory tract infection 1-8 weeks before the onset of the disease. The course of the disease ranges from several days to two weeks. Most patients can heal themselves, but a few may relapse. A very small number of patients may develop cardiac tamponade or constrictive pericarditis.

(B) Rheumatic diseases with pericarditis Acute rheumatic fever is often accompanied by pericarditis, which is often a part of rheumatic pancarditis and is accompanied by other obvious manifestations of rheumatic activity. It is more common in adolescents. Pericarditis can also be seen in other rheumatic diseases, such as systemic lupus erythematosus, rheumatoid arthritis, scleroderma, polyarteritis nodosa, dermatomyositis, etc., and is often a clinical manifestation of the disease.

(III) Uremic type is more common in the late stage of chronic renal failure, which is often caused by urea irritating the pericardium. Its appearance indicates a serious prognosis. If pericardial friction sound occurs in uremic patients undergoing induction hemodialysis therapy, attention should be paid to whether systemic heparinization measures have been adopted to cause intrapericardial bleeding.

(IV) Myocardial infarction: Acute myocardial infarction under the visceral layer of the pericardium can involve the pericardium and cause reactive inflammation, which usually occurs within the first 2-3 days after the infarction.

(V) Hypersensitivity occurs two weeks or more after pericardial trauma, cardiac surgery, cardiac contusion, or myocardial infarction. It may be caused by damage to the pericardial myocardial tissue and antigen-antibody reaction.

(VI) Tumors are commonly caused by metastasis of lung cancer, breast cancer and lymphoma to the pericardium. Leukemia can occasionally invade the pericardium.

(VII) Radiation damage: When the total radiation dose to the chest reaches 1500 rads or more, it can cause vasculitis in the pericardium. The greater the radiation dose, the earlier the pericarditis occurs. There are also cases where clinical manifestations of heart damage appear 3 months or even 6 years after irradiation, and the myocardium and endocardium may also be damaged and fibrosis may occur.