Pericardial effusion and tamponade


(d) Pericardial cavity, part of the inferior mediastinum, in relation to (a) superior mediastinum; (c) pleural cavities; and (e) diaphragm.
Anatomy of the pericardium.
Pericardial pressure-volume relationships in patients who have rapidly (left curve) and gradually (right curve) developed a pericardial effusion. In rapid accumulating effusion (left curve), even a small effusion volume can exceed the limit of parietal pericardial stretch and finally causes a steep rise in pressure. In contrast, slow accumulating effusion (right curve) requires a long time and a large volume to exceed the limit of pericardial stretch because of the activating compensatory mechanisms.
  • Always consider in patient with PEA
  • Always consider in patient with penetrating trauma anywhere in the cardiac box (80% result in tamponade)
    • Gun shot wounds are less likely to result in tamponade because pericardial defect is larger
    • Right ventricle is the most commonly injured chamber of the heart due to its anatomic location[1]
  • Pathophysiology
    • Increased pericardial pressure > decreased RV filling > decreased cardiac output


Clinical Features

  • Chest pain, shortness of breath, cough, fatigue
  • CHF-type appearance
  • Tachycardia
  • Narrow pulse pressure
  • Friction rub
  • Pulsus paradoxus (dec in BP on inspiration)
  • Beck's Triad (33% of patients)

Differential Diagnosis

Chest pain





Pulsus Paradoxus

  • >10mmHg change in systolic BP on inspiration


Massive pericardial effusion on chest x-ray
  • Enlarged cardiac silhouette


Sinus tachycardia with low QRS voltage and electrical alternans
  • Often normal
  • Tachycardia (bradycardia is ominous finding)
  • Electrical alternans
  • Low voltage
    • All limb lead QRS amplitudes <5 mm or I+II+III<15;[2]
    • OR All precordial QRS amplitudes <10 mm or V1+V2+V3<30


Transthoracic echo of pericardial effusion showing "swinging heart"
Pericardial effusion on ultrasound
Collapse M mode
MV inflow variation
  • Pericardial effusion
    • In acute cases, even a relatively small build up of pericardial fluid can lead to hemodynamic compromise
    • Differentiate pericardial effusion from pleural effusion using the parasternal long axis view. Pericardial effusions will have an anechoic stripe between the left atrium and descending thoracic aorta. In a pleural effusion, the stripe will be seen behind the descending thoracic aorta.[3]
  • Classical ultrasound findings
    • Diastolic collapse of the right atrium (in atrial diastole)
    • Diastolic collapse of the right ventricle
    • Plethoric IVC (highly sensitive but low specificity)[4]
  • Evaluating systolic vs. diastolic phases with M-mode
    • Position in PSL view with M-mode line through where RV appears to collapse
    • Allow M-mode line to pass through where the anterior MV hits the septum in diastole (much like evaluation of EPSS - see Formal echocardiography)
    • The period of time where the anterior leaflet of the mitral valve is open (and closest to the septum) is the period of diastole. Evaluate the anterior free wall of the right ventricle for collapse. The longer period of collapse during diastole is an indicator for advanced tamponade physiology
  • Valvular pulsus paradoxus
    • Obtain apical 4-chamber view, place doppler indicator in either MV or TV location
    • Doppler interrogation across the mitral valve will demonstrate exaggerated respiratory variability of transvalvular flow
    • MV inflow respiratory variation, difference from highest velocity to lowest, as a percentage of highest velocity[5]
      • > 25%, likely tamponade physiology
      • > 40% for tricuspid inflow variation
      • Helpful in thickened RV and RA from longstanding pulmonary hypertensive patients


Hemorrhagic Tamponade

Non-hemorrhagic Tamponade


  • To OR if traumatic and hemodynamically unstable
  • Admit with cardiology/CT surgery consult

See Also

External Links


  1. Gunay C, et al. Surgical challenges for urgent approach in penetrating heart injuries. Heart Surg Forum. 2007;10(6):E473-E477. doi:10.1532/HSF98.20071098
  2. Mattu A, Brady W. ECGs for the Emergency Physician 2, BMJ Books 2008.
  3. Randazzo MR et al. Acad Emerg Med, 2003. PMID: 12957982
  4. What echocardiographic findings suggest a pericardial effusion is causing tamponade? Am J Emerg Med. 2019 Feb;37(2):321-326. doi: 10.1016/j.ajem.2018.11.004. Epub 2018 Nov 17.
  5. Rajagopalan N, Garcia MJ, Rodriguez L, Murray RD, Apperson-Hansen C, Stugaard M, Thomas JD, and Klein AL. Comparison of new Doppler echocardiographic methods to differentiate constrictive pericardial heart disease and restrictive cardiomyopathy. Am J Cardiol. 2001 Jan 1;87(1):86-94.