Pericardial effusion – Echocardiography

Pericardial effusion – Echocardiography

Pericardial effusion on echocardiography is typically classified based on size, location, and hemodynamic significance. Hereโ€™s a structured breakdown:


1. By Size (based on echo-free space in diastole)

  • Small: <10 mm (usually <200 mL of fluid)
  • Moderate: 10โ€“20 mm (โ‰ˆ200โ€“500 mL)
  • Large: >20 mm (>500 mL)
  • Very Large: >25 mm

2. By Distribution

  • Circumferential: fluid surrounds the entire heart.
  • Loculated: localized collection, often post-surgery, post-trauma, or with infection.
  • Posterior only: may be seen in small effusions.
  • Anterior only: rare, usually post-operative.

3. By Character (echo appearance)

  • Anechoic (clear fluid): usually transudate or serous.
  • Echo-dense (heterogeneous, fibrin strands): suggests exudative effusion (infection, malignancy, hemopericardium).

4. By Hemodynamic Significance

  • No tamponade: only echo-free space without chamber collapse.
  • Pre-tamponade: early diastolic collapse of right atrium/ventricle, but no clinical compromise.
  • Cardiac tamponade: right atrial or right ventricular diastolic collapse, plethoric IVC, exaggerated respiratory variation in Doppler inflows.

ClassificationCriteria
SizeSmall (<10 mm), Moderate (10โ€“20 mm), Large (>20 mm), Very Large (>25 mm)
DistributionCircumferential, Loculated, Posterior only, Anterior only
CharacterAnechoic (clear), Echo-dense (fibrin, clots, debris)
HemodynamicsNo tamponade, Pre-tamponade, Tamponade

1. A pericardial effusion measuring 8 mm on echo is classified as:
A) Small
B) Moderate
C) Large
D) Very large
Small effusion = echo-free space <10 mm (<200 mL).

2. A circumferential pericardial effusion means:
A) Only behind LV
B) Surrounds the entire heart
C) Limited to anterior wall
D) Post-surgical loculation
Circumferential effusion surrounds the whole heart.

3. Which echo feature suggests cardiac tamponade?
A) Anechoic fluid only
B) Small posterior effusion
C) RA/RV diastolic collapse
D) Minimal pericardial strands
Tamponade = RA/RV collapse + plethoric IVC + Doppler variation.

4. A fibrinous pericardial effusion on echo appears as:
A) Clear anechoic fluid
B) Posterior-only collection
C) Echo-dense with fibrin strands
D) Uniform circumferential rim
Exudative/hemorrhagic effusion appears echo-dense with fibrin strands.

5. Which is typical of a moderate effusion?
A) <10 mm separation
B) 10โ€“20 mm separation
C) >20 mm separation
D) Loculated fluid only
Moderate effusion = 10โ€“20 mm (โ‰ˆ200โ€“500 mL).

6. Very large pericardial effusion is defined as:
A) 10โ€“20 mm
B) >20 mm
C) >25 mm
D) <10 mm
Very large effusion = echo-free space >25 mm.

7. Loculated pericardial effusion is most often seen after:
A) Viral pericarditis
B) Uremia
C) Cardiac surgery or trauma
D) Hypothyroidism
Loculated effusion is common after cardiac surgery or trauma.

8. Posterior-only pericardial effusion is usually:
A) Small effusion
B) Very large effusion
C) Always tamponade
D) Malignant
Small effusions often appear only posteriorly on echo.

9. A transudative effusion appears on echo as:
A) Anechoic, clear fluid
B) Fibrinous with strands
C) Echo-dense with clots
D) Loculated
Transudates are typically anechoic and echo-free.

10. Which Doppler finding supports tamponade?
A) Normal inflow
B) Exaggerated respiratory variation in mitral/tricuspid inflow
C) Increased LV ejection fraction
D) Tachycardia alone
Tamponade causes exaggerated respiratory variation in ventricular inflow.

11. Which chamber usually collapses first in tamponade?
A) Right atrium
B) Left atrium
C) Right ventricle
D) Left ventricle
RA collapse occurs first in tamponade physiology.

12. Which feature favors effusion over epicardial fat?
A) Anterior echo-free space only
B) Posterior echo-free space
C) Homogeneous echogenic tissue
D) Fixed location near RV
Effusions collect posteriorly, unlike epicardial fat which is anterior.

13. Plethoric IVC on echo in tamponade means:
A) Dilated IVC with reduced inspiratory collapse
B) Completely collapsed IVC
C) Normal size with good collapse
D) Pulsatile IVC
Tamponade shows a dilated IVC with poor inspiratory collapse.

14. Most specific sign of tamponade on echo is:
A) Tachycardia
B) RA/RV diastolic collapse
C) Pleural effusion
D) LV hypertrophy
RA/RV diastolic collapse is highly specific for tamponade.

15. Echo-dense pericardial effusion most often indicates:
A) Transudative
B) Exudative/hemorrhagic
C) Normal variant
D) Epicardial fat
Echo-dense fluid suggests infection, malignancy, or hemopericardium.

16. Small effusion is usually:
A) <10 mm, often posterior only
B) 10โ€“20 mm circumferential
C) >20 mm circumferential
D) Always loculated
Small effusions (<10 mm) are often posterior-only on echo.

17. What is the most reliable indicator of hemodynamic compromise?
A) Size of effusion
B) Chamber collapse with Doppler variation
C) Posterior-only effusion
D) Fibrin strands
Hemodynamic impact is best judged by collapse patterns + Doppler variation, not size alone.

18. Which effusion is most likely malignant?
A) Small posterior
B) Transudative clear fluid
C) Large, echo-dense, with loculations
D) Anterior fat pad
Malignant effusions are often large, loculated, and echo-dense.

19. Which best distinguishes pericardial effusion from pleural effusion?
A) Both appear echo-free
B) Pericardial effusion lies anterior to descending aorta
C) Pleural effusion anterior to aorta
D) Only pleural effusion has fibrin
On parasternal long axis, pericardial effusion lies anterior to descending aorta; pleural is posterior.

20. Which of the following is NOT part of echo classification of pericardial effusion?
A) Size
B) Distribution
C) Hemodynamic significance
D) Serum cholesterol level
Classification is by size, distribution, character, and hemodynamic impactโ€”not cholesterol level.


๐Ÿ“Š Pericardial Effusion โ€“ Echocardiographic Classification
By Size ๐Ÿ”น Small: <10 mm (<200 mL)
๐Ÿ”น Moderate: 10โ€“20 mm (200โ€“500 mL)
๐Ÿ”น Large: >20 mm (>500 mL)
๐Ÿ”น Very Large: >25 mm
By Distribution ๐Ÿ”น Circumferential (surrounds heart)
๐Ÿ”น Loculated (post-surgical/adhesions)
๐Ÿ”น Anterior only
๐Ÿ”น Posterior only
By Character ๐Ÿ”น Anechoic (clear, transudate)
๐Ÿ”น Echo-dense (fibrin, clots, debris, exudate)
By Hemodynamics ๐Ÿ”น No Tamponade: echo-free space only
๐Ÿ”น Pre-Tamponade: RA/RV diastolic collapse, no clinical compromise
๐Ÿ”น Tamponade: RA/RV collapse + plethoric IVC + Doppler variation
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