Pericardial effusion and tamponade

Background

  • 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
  • Pathophysiology
    • Increased pericardial pressure > decreased RV filling > decreased cardiac output

Etiology

Clinical Features

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

Differential Diagnosis

Chest pain

Critical

Emergent

Nonemergent

Evaluation

Pulsus Paradoxus

  • >10mmHg change in systolic BP on inspiration

CXR

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

ECG

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;[1]
    • OR All precordial QRS amplitudes <10 mm or V1+V2+V3<30

Ultrasound

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.[2]
  • Classical ultrasound findings
    • Diastolic collapse of the right atrium (in atrial diastole)
    • Diastolic collapse of the right ventricle
    • Plethoric IVC
  • 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)
  • Valvular pulsus paradoxus
    • 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[3]
      • > 25%, likely tamponade physiology
      • > 40% for tricuspid inflow variation
      • Helpful in thickened RV and RA from longstanding pulmonary hypertensive patients

Management

Hemorrhagic Tamponade

Non-hemorrhagic Tamponade

Disposition

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

See Also

References

  1. Mattu A, Brady W. ECGs for the Emergency Physician 2, BMJ Books 2008.
  2. Randazzo MR et al. Acad Emerg Med, 2003. PMID: 12957982
  3. 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.