Pericarditis

Pericarditis refers to inflammation of the pericardium. It can be acute, recurrent, or chronic. It often leads to formation of a pericardial effusion. It accounts for up to 5% of patients with chest pain in which acute coronary syndrome is initially suspected. It more frequently affects men than women.

Pericarditis may occur together with myocarditis, called perimyocarditis or myopericarditis.

The prognosis is good with treatment, but without treatment the disease usually recurs. In non-viral cases, the pericardial effusion may be large enough to cause cardiac tamponade. Constrictive pericarditis may also develop.

Etiology

There are many possible causes of pericarditis, but the most common are viral and autoimmune.

Infectious
- Viral (coxsackie, others)
- Bacterial
Non-infectious
- Autoimmune (SLE, Sjögren, RA, +++)
- Metastasis
- Metabolic disorder
- Dressler syndrome

In many cases, the exact etiology cannot be determined, but viral causes are assumed to cause most of these idiopathic cases.

Dressler syndrome is an idiopathic pericarditis occuring weeks after a myocardial infarction.

Classification

Exudative pericarditis – causes pleural effusion
Fibrinous pericarditis – does not cause effusion

Clinical features

There’s a typical form of chest pain in acute pericarditis, described as a sharp pain in the retrosternum which worsens on inspiration. The pain improves when leaning forward. Other symptoms include fever and dyspnoea.

A pericardial friction rub on auscultation is typical, which sounds like high-pitched scratching. It’s best heard over the left sternal border. If there’s a large pericardial effusion, heart sounds may be distant.

Diagnosis and evaluation

The diagnosis is based on typical clinical features and findings on ECG, echo, and imaging.

X-ray – enlarged cardiac silhouette due to pericardial effusion
ECG – widespread ST elevation or PR depression or T inversion
Echocardiography – pericardial effusion and thickened pericardium. Pericardial effusion occurs in only 2/3 of cases and there are usually only small amounts
Inflammatory markers may be elevated
Inflammation of the pericardium can be visualised on CT or MRI

To diagnose acute pericarditis, two of the following features must be present:

Typical pericardial pain
Pericardial friction rub
Typical ECG changes
Pericardial effusion

Treatment

First-line treatment are NSAIDs + colchicine + exercise reduction. NSAIDs are titrated down or discontinued after 1-2 weeks, while colchicine is continued for 3 months.

Second line are glucocorticoids and other immunosuppressants. Especially anakinra (anti-IL-1) is shown to be effective. In case of chronic pericarditis, pericardiectomy is an option.