The pericardium is a double-layered fibroserous sac that surrounds the heart. The purpose of the pericardium includes protecting the heart from infections and reducing friction between the heart and neighboring organs or structures. When the heart expands and contracts, the two layers of the pericardium rub against each other. Fortunately, there is a naturally occurring fluid in the space between the two layers, known as the pericardial fluid. This yellowish fluid helps to reduce friction.
In a healthy human being, there are from 15 to 50 ml of the pericardial fluid within the pericardial cavity. However, when there is a build-up or accumulation of more fluid than normal, it is a condition called pericardial effusion. Over time, the accumulation of fluid causes the pericardium to expand to accommodate the excess fluid. Unfortunately, the pericardium’s elasticity is limited. In extreme cases, pericardial effusion can lead to pericardial tamponade (also known as cardiac tamponade).
Cardiac tamponade occurs when the abnormal increase of fluid induces pressure on the heart. The pressure prevents the heart from expanding properly. Consequently, the heart pumps less blood, which causes hemodynamic issues to arise, including decreasing the supply of oxygenated blood to other parts of the body. This can lead to the failure of other organs in the body and eventually death.
In the early stage of pericardial effusion, it may be asymptomatic unless the pericardial effusion is due to an inflammation of the pericardial sac. The patient, in that case, would experience symptoms of inflammation like fever, shortness of breath, and fatigue.
The speed of fluid accumulation determines how fast a pericardial effusion can result in cardiac tamponade. Chronic pericardial effusion is the gradual accumulation of fluid that affords the pericardium enough time to expand and adjust to accommodate the excess fluid. In that scenario, it may require up to one or two liters of the fluid build-up to trigger cardiac tamponade. However, rapid fluid accumulation may only take 100 to 150 ml to bring on cardiac tamponade. This condition is known as acute pericardial effusion.
The most common cause of pericardial effusion in developed parts of the world is viral pericarditis (inflammation of the pericardium). It is rare to find pericardial effusion caused by tuberculosis or other bacterial or parasitic organisms in developed countries. Unfortunately, that is not the case in developing countries, where poor living conditions and medical treatment allows for the spread of tuberculosis.
The etiologies (cause or origin of the disease or condition) of pericardial effusion are numerous and can be idiopathic (having no identifiable cause). Conditions that may bring about pericardial effusion include severe kidney failure, heart failure, cancer, and immune system disorders.
Besides considering the age, health history, and symptoms, it is essential to note the severity and identify the cause of the pericardial effusion to treat it effectively. In minor cases of pericardial effusion, doctors monitor the progression of the condition by regular echocardiograms. If the pericardial effusion is due to an infection or underlying disease, the disease or infection is treated. In some cases, patients might require no treatment at all.
However, if the pericardial effusion becomes chronic or results in cardiac tamponade, a pericardiocentesis (a procedure for removing built-up fluid in the pericardium) becomes necessary.
