Pericardial Effusion-> Tamponade?

Congratulations to Jona Karlsson for this week's best image.  He identified a patient with a pericardial effusion with indention of the right ventricle during diastole, suggestive of tamponade.  

As a the pressure in a pericardial effusion increases, it overcomes the pressure in the right side of the heart, preventing filling. As tamponade develops, we expect to see Beck's Triad.  The physical exam findings of Beck's Triad are not present in every patient, so the bedside ultrasound can assist in the diagnosis.  On ultrasound, expect to see a pericardial effusion with exaggerated collapse of the right atrium during atrial systole and indention of the right ventricular diastolic collapse.  The patient's IVC should be "plethoric" or dilated with minimal respiratory variation.

Identification of pericardial effusion on bedside ultrasound is well within the scope of practice of the average emergency physician. Interpreting tamponade physiology is an example of the "emerging" applications in the ACEP 2008 guidelines.