cardiac_tamponadeWhat is a cardiac tamponade? It is a clinical state where pericardial fluid causes hemodynamic compromise. With bedside ultrasonography in most Emergency Departments now, it’s relatively easy to detect a pericardial effusion.

But what we more want to know in the immediate setting is: Is this cardiac tamponade?

You can look for RA systolic or RV diastolic collapse. What if it’s equivocal? How good is the clinical exam and EKG in ruling out a tamponade?


Poor to average, at best. The Beck’s triad of hypotension, distended neck veins, and muffled heart sounds are important to remember … only on tests.


Think about performing a pulsus paradoxus test to see if it’s >12 mmHg. This is a sign of physiologic compromise. Note that the typical cutoff has been 10 mmHg but 12 mmHg is a more specific test.

Adapted from 1
Go to the ALiEM Cards site for more resources.

Thanks to Dr. Hemal Kanzaria for suggesting this JAMA article!

Roy CL, Minor MA, Brookhart MA, Choudhry NK. Does This Patient With a Pericardial Effusion Have Cardiac Tamponade? JAMA. 2007;297(16):1810. doi: 10.1001/jama.297.16.1810
Michelle Lin, MD
ALiEM Editor-in-Chief
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco
Michelle Lin, MD


Professor of Emerg Med at UCSF-Zuckerberg San Francisco General. Founder of ALiEM @aliemteam #PostitPearls
Michelle Lin, MD