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Pericardial Effusion
General Considerations
- Abnormal amount of fluid in the pericardial space, defined as the space between the visceral and parietal layers of the pericardium
- Normally contains about 20-50 cc of fluid
- Fat covers outside of heart and outside of pericardium sandwiching pericardial space between the two layers
- Normal thickness of pericardium (parietal pericardium and fluid in space) is 2-4 mm
Clinical Findings
- Small effusions frequently produce no symptoms
- Chest pain or discomfort with a characteristic of being relieved by sitting up or leaning forward and worsened in the supine position\
- Syncope
- Palpitations
- Shortness of breath, tachypnea
- Muffled or distant heart sounds, tachycardia
- Hypotension
- Jugular venous distension
- Pulsus paradoxus
- Decrease in systolic pressure with inspiration of more than 10 mm Hg
- Rate of accumulation of fluid is proportional to severity of symptoms
- The faster the fluid accumulates, the more severe the symptoms
- Requires about 150-250cc before cardiac tamponade occurs
- About 7-10% of those with pericardial effusion are at risk for developing tamponade
- Tamponade compresses heart and causes low cardiac output
- Most effusions do not lead to cardiac tamponade
- Size of cardiac silhouette is frequently increased
- Tamponade is rarely seen in association with pulmonary edema in the lungs
Causes
Causes of Pericardial Effusions |
Cause |
Remarks |
Myocardial infarction |
Most common |
Collagen vascular disease |
Especially Lupus |
Trauma |
Surgical or accidental |
Metastatic disease |
Serosanguinous effusion |
Tuberculosis |
Uncommon except in AIDS |
Viral infection |
Coxsackie A and B virus |
Uremia |
18% in acute uremia |
- Other causes
- Serous fluid or transudate
- Congestive heart failure
- Hypoalbuminemia
- Irradiation
- Blood (hemopericardium)
- Rupture of ascending aorta or pulmonary trunk
- Coagulopathy
- Fibrin (produces exudate)
- Pyogenic infection, e.g. staph
- Uremia
- More common in chronic renal disease than acute
Imaging findings
- Conventional radiography
- Suggestive but not usually diagnostic
- "Water bottle configuration" is symmetrically enlarged cardiac silhouette
- Major DDX is cardiomegaly
- Loss of retrosternal clear space
- Non-specific and frequently not valid
- "Fat-pad sign"
- Produced by separation of retrosternal from epicardial fat line >2 mm
- Rapidly enlarging cardiac silhouette with normal pulmonary vascularity
- Echocardiogram
- Study of choice
- Echo-free fluid between the visceral and parietal pericardium
- Early effusions accumulate posteriorly first
- > 1cm is usually defined as a “large” effusion
- CT
- May detect small effusions (50cc)
- Fluid-filled space surrounding the myocardium
- Early effusions accumulate posteriorly first
Treatment
- Medical treatment depends on cause and may include
- Non-steroidal anti-inflammatory agents
- Colchicine
- Steroids
- Antibiotics
- Chemotherapeutic agents
- Pericardiocentesis
- Pericardial sclerosis for recurring effusions
- Tetracycline, doxycycline, 5-fluorouracil
- Pericardial window
- Video-assisted thoracic surgery (VATS)
- Allows for wide resection of pericardium
![Pericardial effusion](../../caseofweek/caseoftheweekpix2007-1/cow274arr.jpg)
Pericardial effusion. Frontal chest radiograph (above) demonstrates a markedly enlarged cardiac silhouette. The differential diagnosis would include cardiomyopathy and pericardial effusion. A single axial, contrast-enhanced CT scan of the chest at the level of the heart shows a large pericardial effusion (white arrows) surrounding the contrast-filled heart (LV=left ventricle). The red arrow points to the myocardium.
For this same photo without the arrows, click here
![pericardial effusion](../../caseofweek/caseoftheweekpix/cow112compwitharrows.jpg)
Pericardial effusion on both frontal chest radiograph and axial CT. Red arrow points to fat outside of
pericardium. Green arrow points to
pericardial space which is 8 mm in this patient (<4 mm is normal.)
The yellow arrow points to ft
outside of heart and the blue arrow to the
myocardium.
![pericardial effusion](../../images/cardiacimages1/pericardialeffusion-CT-ann.jpg)
Pericardial effusion. Axial unenhanced CT scan through the heart shows a moderately large pericardial effusion (blue arrows) surrounding the heart.
For additional information about this disease, click on this icon if seen above.
Requisites-Cardiac Radiology
Dahnert-5th Edition
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