Inflammation of the connective tissue protective covering of the heart can have many causes. It usually manifests as pain behind the sternum and can severely impair cardiovascular function. The pericardium (peri = surrounding; kard = relating to the heart) surrounds the heart muscle as a connective tissue protective sheath. It consists essentially of two skins, only the inner one being firmly fused to the outside of the heart muscle and thus being displaced against the outer skin during its pumping action. Inflammation of the pericardium occurs as an independent disease or is an accompanying reaction of other processes in the organism.
Causes of pericarditis
The most common cause of pericarditis is infection – usually with viruses, less commonly with bacteria and other pathogens.
Rheumatic fever, as complications of infection with certain bacteria, can also cause pericarditis, in many cases involving the endocardium and the heart muscle itself (myocardium). In this case, there is an erroneous reaction of the immune system, in which the defense is directed against the body’s own tissue – in this case heart tissue – and causes inflammatory reactions there. Something similar happens in other autoimmune diseases such as rheumatic diseases of the musculoskeletal system and hypersensitivity reactions to drugs, for example.
It is not uncommon for pericarditis to occur after a heart attack, with an early form within 24 to 48 hours after the attack being distinguished from a late form two to three weeks after.
Other causes of pericarditis that may be considered are:
- Hypothyroidism
- Renal insufficiency
- Connective tissue diseases of the organism
- Tumors growing in the chest
- Cardiac surgery
In 20 to 30 percent of diseases, no clear cause can be found.
Symptoms of pericarditis
As with any inflammation, pericarditis is associated with increased blood flow to the involved tissue structures; inflammatory cells from the circulating blood accumulate in the tissue and increased tissue water is released. Whether and to what extent symptoms occur depends on whether there are only inflammatory deposits in the contact area of the two pericardial membranes or whether fluid also accumulates in the pericardium (effusion).
In the former case – a so-called dry pericarditis – respiratory-dependent chest pain is in the foreground, which typically intensifies when lying down and coughing and decreases when leaning forward.
In the second case, the fluid in the pericardium can interfere with the normal relaxation and blood filling of the heart muscle to such an extent that cardiovascular function is impaired (cardiac tamponade). Signs include physical weakness, difficulty breathing and upper abdominal discomfort.
In the worst case, circulatory shock occurs.
Acute and chronic pericarditis
Basically, a distinction is made between acute pericarditis, which heals after a single treatment, and chronic pericarditis, in which fluid is permanently detectable in the pericardium or episodes of inflammation flare up again and again.
Both forms can be mild or – as described above – lead to acute life-threatening situations due to a pericardial effusion. However, in the acute form, the accumulation of fluid is usually more severe because it is very pronounced (sometimes up to more than a liter) and builds up so rapidly that the heart can no longer compensate for it. Obstruction of cardiac function up to cardiovascular shock with fatal outcome can be the result.
Armored heart as a special form of chronic pericarditis
A special form of the chronic form is the so-called armored heart, in which the pericardium shrinks and scars due to recurrent inflammatory reactions, losing elasticity in the process and, like a rigid mantle, no longer allowing the heart to develop.
