cardiac tamponade

What 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.

PV Card: Cardiac Tamponade

Adapted from [1] Go to ALiEM (PV) Cards for more resources.

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


  1. 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 Founder and CEO
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 SF General. ALiEM Founder @aliemteam #PostitPearls at Bio:
Michelle Lin, MD