Pericardial effusion - Causes and Symptoms

Definition

Pericardial effusion is a collection of fluid in the pericardial space.

The pericardium, the serous membrane that contains and protects the heart, consists of 2 sheets. The first membrane, the visceral pericardium, is closely linked to cardiac muscle tissue and folds back on itself over the origin of the large vessels. In this same point it joins the second strong fibrous leaflet, called parietal pericardium, which is external; in this way a sack-shaped structure is created ( pericardial sac ), in which a thin layer of liquid resides, secreted by the two pericardial sheets.

The pericardial fluid, formed mainly by plasma ultrafiltration, acts as a lubricant, reducing the friction between the opposing surfaces during heart contraction.

Pericardial effusion may be serous (sometimes mixed with fibrin filaments), blood or purulent.

In most cases, the accumulation of fluid in the pericardial space depends on the inflammation of the pericardium (pericarditis) and neighboring tissues. Pericarditis results mainly from viral infections; less often, it is of bacterial, fungal or parasitic origin.

The accumulation of serous fluid is present during autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis and systemic sclerosis), inflammatory disorders (amyloidosis and sarcoidosis) and uremia (renal failure).

A pericardial effusion can also occur after an acute myocardial infarction, trauma (bruising or perforation from a sharp body), thoracic irradiation, chemotherapy and cardiac surgery. Furthermore, it can be induced by different drugs, including hydralazine, isoniazid and phenytoin.

Pericardial effusion may also develop due to primary cardiac tumors or metastatic spread of malignant neoplasms (especially advanced lung or breast cancer, sarcoma, melanoma, leukemia and lymphoma).

Symptoms that may indicate a spill between the two sheets of the pericardium include: chest pain, dyspnea (shortness of breath) and acceleration of the heart rhythm. The condition can lead to cardiac tamponade with hypotension, shock or pulmonary edema.