Acute Pericarditis

Question 1

Acute pericarditis is most commonly secondary to a viral infection and is self-limiting without significant complications in…% of cases.

Answer 1

Acute pericarditis is most commonly secondary to a viral infection and is self-limiting without significant complications in 70-90% of cases.

Question 2

… refers to inflammation of the lining of the heart known as the pericardium.

Answer 2

Pericarditis refers to inflammation of the lining of the heart known as the pericardium.

Question 3

Inflammation of the pericardium can be acute or chronic:

Answer 3

Acute pericarditis: acute-onset chest pain and characteristic ECG features (e.g. saddle ST elevation). Multiple aetiologies. Self-limiting without significant complications in 70-90% of cases.
Chronic pericarditis: long-standing inflammation (> 3 months), usually follows acute episode. Complications include chronic pericardial effusion and constrictive pericarditis due to scarring.

Question 4

There are several terms used in the description of pericarditis and associated disorders:

Answer 4

Pericarditis: inflammation of pericardial sac
Myocarditis: inflammation of the myocardium, which is the muscular tissue of the heart
Perimyocarditis: inflammation of both the pericardial sac and myocardium with a primarily myocarditic syndrome
Myopericarditis: inflammation of both pericardial sac and myocardium with a primarily pericarditic syndrome

Question 5

Aetiology & pathophysiology of acute pericarditis

Answer 5

In developed countries, the majority of cases are due to a transient viral infection.
In most cases of acute pericarditis, the pericardial sac is acutely inflamed with infiltration of immune cells secondary to an acute infection or as manifestation of a systemic disease.

Question 6

The aetiology of acute pericarditis is numerous:

Answer 6

Idiopathic: significant proportion of cases are idiopathic. Majority thought to represent undiagnosed viral infections. Clinically, unable to distinguish between viral and true idiopathic pericarditis.
Viral: most common. 1-10% of cases. Short-lived lasting 1-3 weeks. Often due to coxsackievirus B. Variety of other viruses implicated (e.g. influenza, echovirus, adenoviruses, enterovirus, etc)
Bacterial: approximately 1-8% of cases. May occur due to haematogenous spread, extension from pulmonary infection or as complication of endocarditis or trauma. Multiple organism implicated including gram positive and negative.
Tuberculosis: must be investigated in high prevalence areas or high-risk patients (e.g. immunodeficiency). 4% of all cases. More insidious onset. High-risk of chronic pericarditis and constrictive complications.
Systemic disease: underlying systemic inflammatory disease (e.g. rheumatoid arthritis). Features of systemic disease on clinical assessment. May complicate chronic kidney disease (e.g. uraemic pericarditis), hypothyroidism or post-myocardial infarction
Other: drugs, radiotherapy and trauma

Question 7

Dressler’s syndrome

Answer 7

This is a specific autoimmune form of acute pericarditis that occurs 2-3 weeks following a myocardial infarction.

Unlike the immediate post-myocardial infarction pericarditis due to direct inflammation from transmural infarction, Dressler’s syndrome is thought to be an autoimmune reaction to myocardial antigens post infarction.

Question 8

Prognostic risk factors in acute pericarditis

Answer 8

Fever > 38º
Subacute onset
Large pericardial effusion
Cardiac tamponade
Poor response to 1 week of treatment

Question 9

Minor risk factors in acute pericarditis

Answer 9

Myopericarditis
Immunosuppression
Trauma
Oral anticoagulant therapy

Question 10

The cardinal feature of acute pericarditis is ..

Answer 10

The cardinal feature of acute pericarditis is chest pain.

Question 11

Symptoms - acute pericarditis

Answer 11

Chest pain: sharp, pleuritic (worse on inspiration). Characteristically better on leaning forward and sitting up
Fever: usually low-grade
Breathlessness: may indicate development of complications such as pericardial effusion or myocardial involvement.
Cough

Question 12

Signs of acute pericarditis

Answer 12

Pericardial friction rub: scratchy or squeaking sound heard over the heart
Features of cardiac tamponade: muffled heart sounds, distended JVP, pulsus paradoxus (fall in blood pressure > 10 mmHg during inspiration), hypotension

Question 13

Formal diagnosis of acute pericarditis is based on finding two of the following four features:

Answer 13

Typical chest pain
Pericardial friction rub
Characteristic ECG features
New or worsening pericardial effusion

Question 14

Patients with suspected acute pericarditis require ..

Answer 14

Patients with suspected acute pericarditis require formal assessment, blood tests, ECG, CXR and echocardiogram.

FBC
U&Es
CRP
Troponin: if elevated, suggests myocardial involvement (i.e. myopericarditis)

Selective blood tests may be completed based on suspected aetiology. These include cultures, virology, autoimmune screen or tuberculosis work-up.

Question 15

ECG findings in acute pericarditis

Answer 15

The characteristic ECG findings are widespread saddle-shaped ST elevation with PR depression.

Question 16

The mainstay of treatment for acute pericarditis is the use of …

Answer 16

The mainstay of treatment for acute pericarditis is the use of NSAIDs, aspirin or colchicine.

Question 17

The mainstay of treatment for acute pericarditis is the use of NSAIDs, aspirin or colchicine.

Answer 17

First-line: ibuprofen (600 mg TDS) or aspirin (600 mg TDS). Ensure no contraindications. Give for 1-2 weeks until pain resolves. Tapering advised. Gastric protection (e.g. proton pump inhibitor).
Adjuvant: colchicine (2-3 mg loading then 0.5 mg BD) can be given as an adjunct to NSAID treatment or as primary therapy in patients with contraindications. Typically longer course (i.e. 3 months)
Other: short courses of oral corticosteroids may be required in patients who fail to respond, those with contraindications or development of side-effects.

Question 18

The majority of patients with acute pericarditis make a good recovery.

Rare, but serious, complications of acute pericarditis include .. (2)

Answer 18

Cardiac tamponade: compression of the heart by pericardial fluid, which can lead to cardiovascular collapse and cardiac arrest. Requires urgent pericardial paracentesis. Rarely occurs in viral/idiopathic acute pericarditis
Chronic pericarditis: chronic inflammation of the pericardial sac and high-risk for developing constrictive pericarditis. Around 1% risk of constrictive pericarditis from idiopathic/viral aetiology compared to 20-30% for bacterial aetiology including TB.

Question 19

In idiopathic/viral pericarditis, around… of patients without treatment will develop recurrent disease. Incessant (pericarditis for 4-6 weeks) and recurrent (repeated acute episodes) pericarditis can be problematic.

Answer 19

In idiopathic/viral pericarditis, around 15-30% of patients without treatment will develop recurrent disease. Incessant (pericarditis for 4-6 weeks) and recurrent (repeated acute episodes) pericarditis can be problematic.