Pericardial effusion is an abnormal accumulation of excess fluid between the pericardium and the heart; this space is called pericardial cavity. Normal levels of pericardial fluid are from 15 to 50 ml. Because of the limited amount of space in the pericardial cavity, pericardial effusion leads to an increased intrapericardial pressure and this can negatively affect heart function. Pericardial effusion is often related to inflammation of the pericardium which is caused by disease or injury, but it can also occur without inflammation. Sometimes, pericardial effusion can be caused by the accumulation of blood after a surgical procedure or injury. When there is a pericardial effusion with enough pressure to adversely affect heart function, it is called pericardial tamponade, which can be life-threatening. Pericardial effusions can be found in up to 20% of cancer patients.
The seriousness of the condition depends on the primary cause and size of the effusion and whether it can be treated effectively. Causes that can be treated or controlled, such as an infection due to a virus or heart failure, allows the patient to be effectively treated and remain free of pericardial effusions. Pericardial effusion caused by other conditions, such as cancer, is very serious and should be diagnosed and treated promptly.