Pericarditis

Pericarditis refers to inflammation of the pericardium

The pericardium is a sac within which the heart sits. This sac has 2 layers known as the visceral and parietal layers separated by a potential space which contains about 1050mls of fluid. Acute inflammation of this sac is known as acute pericarditis. If the inflammation spreads to the surface of the heart itself, it is termed myopericarditis.

About 5% of patients who present to A+E with chest pain which is not deemed to be a heart attack or angina are ultimately diagnosed with pericarditis.

Why does this inflammation happen? There are a multitude of causes and the most common causes depend on which part of the world you are in. In developed countries the commonest cause of acute pericarditis is a presumed viral infection. Common viruses that have been identified include Parvovirus B19, EBV, CMV, Herpes Simplex Virus etc)  In developing countries, common causes of pericarditis are TB and HIV. Other common causes of pericarditis include bacterial infections, kidney failure, rheumatological conditions such as autoimmune conditions/vasculitis (SLE, rheumatoid arthritis, sarcoidosis) and even cancer (mesothelioma; spread from other tumors). Also recent cardiac surgery and a recent heart attack can present with pericarditis.

How does it present?

It may present out of the blue but quite often it may present after a flu like respiratory or gastric illness.

Pericarditis is characterised by often quite severe chest pain but it is usually reasonably easy to distinguish from anginal pain because in pericarditis,the pain is very sharp and actually catches the breath when a person tries to breath in. it is made worse when the patient coughs. It is characteristaiclly better when someone sits up and leans forward. This is because this position reduces the pressure on the paricardium. Pain is a feature in over 95% of patients. It is very prevalent in patients with an infection but may be not as painful in patinets with renal failure or rheumatological problems. The pain may radiate to the the trapezius ridge. 

One of the things that is very helpful to make the diagnosis of pericarditis is to listen to the heart is the presence of a pericardial friction rub. The 2 layers are both inflamed and as the heart moves within the pericardium these two layers rub against each other and can produce a scratchy or squeaky sound that can be heard by an experienced doctor. The absence of a rub does not exclude the possibly of pericarditis but the presence makes it very likely that that is what you are dealing with. To hear it your doctor should get you to lean forwards and hold your breath or even get you on your hands and knees and listen while you are in that position.