Introduction
Pericardial effusion is an increased accumulation of fluid (from about 50 ml) in the pericardium. In order to be able to easily understand this, one should first consider the anatomical conditions in the mediastinum (mediastinal space). In the mediastinum, the heart lies within the pericardium.
The pericardium consists of two parts: One is the outer pericardium fibrosum, which is connected to the diaphragm at the bottom, and the other is the inner pericardium serosum. The pericardium serosum itself consists of two leaves, the so-called “laminae”. The outer of these two leaves is called Lamina parietalis pericardii and is firmly fused with the Pericardium fibrosum.
The inner leaf is called Lamina visceralis pericardii and is by definition also the outermost layer of the heart (= epicardium). There is a gap between these two leaves of the pericardium, where there is usually a small amount of fluid, so that the two leaves can easily slide past each other during movements of the heart and the heartbeat. A healthy amount of fluid is about two to ten milliliters. If the water in the pericardium starts to press on the heart and compress it, thus impeding the heart’s actions, this is called pericardial tamponade or pericardial tamponade.
Symptoms
A small effusion often causes no discomfort. If the effusion slowly increases over time (“chronic effusion”), symptoms are usually felt from a volume of 300 ml. These may consist of shortness of breath (dyspnoea), high blood pressure (hypertension) or palpitations (tachycardia).
In addition, those affected usually feel physically weak and occasionally feel pain behind the breastbone. The large neck veins (jugular veins) may also be congested. Other symptoms that may be noticed by the doctor include soft heart sounds and possibly pericardial rubbing when listening with a stethoscope, as well as enlargement of the liver (hepatomegaly).
Water in the abdomen (ascites) may also occur. If a pericardial effusion occurs within a short period of time (acute effusion), even small amounts (about 150 to 200 ml) can cause severe symptoms that are very similar to a heart attack. An acute occurrence with rapid development can end in cardiogenic shock (pumping failure of the heart), which is why an acute effusion is always an emergency and must be treated accordingly.
