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Pericardial effusion: Difference between revisions
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(Created page with "'''Pericardial effusion''' refers to accumulation of pathological amounts of fluid in the pericardial cavity. In physiological cases there is 15-50 mL of fluid in the cavity. It may cause cardiac tamponade, which is an emergency. If the fluid is blood it's called haemopericardium. == Etiology == * Pericarditis * Tuberculosis * Following heart surgery * Thoracic injury * Metastasis == Pathomechanism == In cases where the fluid accumulates quickly, only small amount...") |
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'''Pericardial effusion''' refers to accumulation of pathological amounts of fluid in the pericardial cavity. In physiological cases there is 15-50 mL of fluid in the cavity. It may cause [[cardiac tamponade]], which is an emergency. If the fluid is blood it's called haemopericardium. | '''Pericardial effusion''' refers to accumulation of pathological amounts of fluid in the pericardial cavity. In physiological cases there is 15-50 mL of fluid in the cavity. It may cause [[cardiac tamponade]], which is an emergency. If the fluid is blood it's called haemopericardium. | ||
'''Cardiac tamponade''' is a condition where a pericardial effusion compresses the heart, leading to life-threatening [[acute heart failure]]. This occurs if the pericardial effusion develops rapidly or is large. It’s an emergency which should be treated empirically even before a proper diagnosis is made. | |||
== Etiology == | == Etiology == | ||
* Pericarditis | * [[Pericarditis]] | ||
* Tuberculosis | * [[Tuberculosis]] | ||
* Following heart surgery | * Following heart surgery | ||
* Thoracic injury | * Thoracic injury | ||
* Metastasis | * Metastasis | ||
* Cardiac wall rupture (trauma, [[Acute myocardial infarction|MI]]) | |||
== Pathomechanism == | == Pathomechanism == | ||
In cases where the fluid accumulates quickly, only small amounts of fluids (100-150 mL) are required to cause symptoms. Symptoms occur because the pressure in the pericardial cavity increases, preventing diastolic filling of the heart and causing | In cases where the fluid accumulates quickly, only small amounts of fluids (100-150 mL) are required to cause symptoms. Symptoms occur because the pressure in the pericardial cavity increases, preventing diastolic filling of the heart and causing cardiac tamponade. | ||
In cases where it accumulates slowly, up to 2 litres may accumulate before symptoms occur. This is because the pericardial sac adjusts and expands to accomondate the increased fluid. | In cases where it accumulates slowly, up to 2 litres may accumulate before symptoms occur. This is because the pericardial sac adjusts and expands to accomondate the increased fluid. | ||
== Clinical features == | == Clinical features == | ||
Pericardial effusion itself is usually not symptomatic until it reaches the point where [[cardiac tamponade]] develops. | Pericardial effusion itself is usually not symptomatic until it reaches the point where [[cardiac tamponade]] develops. Cardiac tamponade has a distinct clinical presentation: | ||
* [[Hypotension]] | |||
* Tachycardia | |||
* Jugular venous congestion | |||
* <abbr>[[Pulsus paradoxus]]</abbr> | |||
== Diagnosis and evaluation == | |||
A [[chest x-ray]] may not always show a pericardial effusion. The cardiac shadow may be enlarged. If the effusion is large enough, the heart may appear water bottle-shaped, called "water bottle sign". Echocardiography is the investigation best suited to evaluate pericardial effusion, as it will directly visualise the anechoic fluid around the heart. | |||
If cardiac tamponade is suspected based on the clinical features, one should not waste time with time-consuming investigations. A quick echocardiography to confirm pericardial fluid, together with typical clinical features, is usually sufficient to start treatment. | |||
Should one make these investigations (for example if the diagnosis isn't immediately clear), they might show the following: | |||
* [[ECG]] – low voltage, electrical alternans | |||
** Electrical alternans refers to alternating amplitude (height) of the QRS complex with each heartbeat | |||
* [[Echocardiography]] – large effusion, collapse of chambers, swinging of the heart | |||
== Treatment == | |||
In case of small pericardial effusions, one can watchfully wait for it to either progress or regress. In case of larger effusions, pericardiocentesis is necessary, under [[ultrasound]] or [[Fluoroscopy|fluoroscopic]] guidance. | |||
Treatment for cardiac tamponade should not be delayed due to diagnostic evaluations. Treatment is by pericardiocentesis. If unsuccessful, surgery may be necessary. | |||
[[Category:Cardiology]] | |||
[[Category:Internal Medicine (POTE course)]] | |||