Pericardial Effusion: Overview of Aetiology, Pathophysiology, Diagnosis, and Management

The pericardium is a membrane that envelopes the heart and the proximal great vessels. In normal physiological conditions, there is approximately 10-50 ml of pericardial fluid. However, accumulation of pericardial fluid can occur due to inflammation or infection of the pericardium and adjacent structures. This may be an asymptomatic and incidental finding following imaging for another disease process, or the patient may present in shock due to cardiac tamponade. It is important to note that it is the rate of accumulation, not absolute size, that primarily determines symptoms. Whilst the clinical suspicion may be raised by the history, examination, electrocardiogram, or chest X-ray, the echocardiogram is the mainstay of diagnosis. Options for treatment will depend on the cause and haemodynamic consequences. This article will consider the aetiology, pathophysiology, investigations and management of pericardial effusions.