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 10-50mls 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 may 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 characteristically better when someone sits up and leans forward. This is because this position reduces the pressure on the pericardium. 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 patients with renal failure or rheumatological problems. The pain may radiate to 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 possibility 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.

Pericarditis can be associated with ECG changes – specifically something called ST elevation. ST elevation is also seen in people having a heart attack and therefore it becomes important to know how to distinguish between the 2 so that people with pericarditis may not be subjected to the treatment reserved for a heart attack as this may be harmful to them. The way to distinguish between a heart attack is that in pericarditis, we tend to see concave ST elevation whereas in heart attacks we tend to see more convex ST elevation. In addition, the ST elevation tends to be widespread and seen in the majority of the ECG leads. With a heart attack, the problem is a blockage in a vessel supplying a certain area of the heart and therefore you would only expect to see the changes in those leads that are supplying that particular area.

When we see ECG changes and we see typical changes in about 60% of patients, it signifies some irritation of the heart itself rather than just the sac.

This is not an absolute finding meaning that sometimes those differences may not be obvious and even experienced professionals can be misled. However if the pain is sharp and pleuritic and there is a rub and the ECG shows concave ST elevation then it makes the diagnosis of pericarditis much more likely.

Blood tests

Up to 80% of patients will have elevated markers of inflammation such as an elevated white cell count or CRP levels. 30% of patients may even have elevation in troponin levels which signify that there is some inflammation of the heart muscle itself and in this setting, the diagnosis is termed myopericarditis.

Who needs to stay in hospital?

If you have fever, the symptoms have presented over a number of weeks rather than suddenly, if you have not responded to simple anti-inflammatory medications, if you are immunocompromised or there is evidence of a lot of fluid in the pericardial cavity (I.e a pericardial effusion) then it is perhaps a good idea to stay in hospital as the features point to a more complicated course.

What are the complications associated with pericarditis?

Generally the prognosis of pericarditis depends on the aetiology. If it is a viral cause, then the prognosis is generally excellent and people make a full recovery within 4-6 weeks. The main problem for most patients is the pain that they experience and this often needs some symptomatic relief but with strong painkillers, the pain will usually respond well.

If the pericarditis is due to a bacterial infection or due to cancer, then pericarditis can be associated with a much higher mortality of 20-30%

There are a few important things to be aware of which may complicate pericarditis. 

Firstly – if there is a lot of inflammation, then fluid can build up in the potential space between the 2 layers of the pericardium and this can therefore stop the heart from filling with blood and if it does then that can become a life threatening emergency because if  the heart is hampered from filling with blood then it will not be able to pump much blood out. This is termed a pericardial effusion and I feel that all patients admitted to hospital with pericarditis should have an ultrasound of the heart to look for this possible complication. If there is fluid but it is not causing extrinsic compression then just by controlling the inflammation with medications, the fluid will resolve. If on the other hand the fluid is actually interfering with the heart filling up with blood then it may need draining by inserting a needle under local anaesthetic.

Secondly, if there is bad inflammation of the pericardium then sometimes the layers can stick to each other and this can stop the pericardium from being compliant and moving with the heart. If this happens the heart is no longer in a nice pliant bag but more in a hard stiff case and again this can have the effect of stopping the heart from filling with blood and therefore impact on how much blood is pumped out. This condition is termed constrictive pericarditis and complicates about 1% of pericarditis. This is a problem that becomes more troublesome several months or years after the acute event and patients may present with breathlessness, leg swelling and all the signs of heart failure but when you look at the heart it looks like it is pumping ok so you can be misled into thinking that there is no problem with the heart. However there is a problem with the heart in that although the heart can pump well, it is restricted from relaxing to accommodate blood and therefore it pumps out a lot less blood with each beat. It is very important for doctors to bear constrictive pericarditis in mind because if indeed this is confirmed then the pericardium can be stripped off the heart surgically and the patient is essentially cured.

Another problem is that sometimes if you have myocardial involvement I.e myopericarditis, it can cause the heart to weaken and this may require supportive treatment with medications for heart failure (diuretics, ACE inhibitors and beta blockers etc) but generally the heart strengthens back up in more than 90% of cases within a few months to a year

Perhaps the biggest problem is that about 30% of pericarditis can become recurrent especially if a medicine called Colchicine is not used.

What is the treatment?

I’ll talk you through the treatment of pericarditis first and then treatment of recurrent pericarditis.

The mainstay of treatment is to use anti-inflammatory agents such as non-steroidal eg. Aspirin to Brufen but they are generally used at high doses so the usual recommendations are Brufen 600-800mg every 8 hours or Aspirin 750mg to 1g three times daily. The problem of course is that non-steroidals can increase the risk of ulcers by 4-fold and they can also increase blood pressure and affect the kidneys and therefore may not be for everyone and it is always good to check with the doctor to see if these would be indicated in you.

Another medication that can be used is Colchicine and this is usually recommended in addition to the non-steroidal agents. Colchicine has been shown to significantly reduce symptoms persistence at 72 hours and also is associated with a reduced recurrence of pericarditis. Once the inflammatory markers start falling the colchicine is tapered down

Steroids

For patients who do not respond to NSAIDs or colchicine, one can use low dose steroids. I want to emphasise low dose because high dose steroids paradoxically have been linked with an increase in risk of recurrence. 

In patients with recurrent pericarditis, one could use stronger immunosuppressants such as Methotrexate and mycophenolate or even azathioprine.  There is some interest in a new set of medications called IL-1 blockers (Anakinra) which may also reduce recurrent episodes. 

Finally if none of these measures work, then as a last resort, it may be possible to do a pericardiectomy which involves surgical removal of the pericardium.

One other thing to know about is that if you happen to be a competitive athlete then it is generally recommended that you abstain from competition for about 3 months.

I hope you found this useful. Here is a link to the video on this subject.

Pericarditis

Keywords: Pericarditis; myopericarditis; chest pain; yorkcardiology