COTW March 10, 2020: 65 y/o M with worsening dyspnea

A 65 y/o male with history of HTN, type 2 DM, ESRD comes in with dyspnea on mild exertion for several weeks. A few weeks ago, he completed a course of abx for CAP, but was not improving. Labs and CXR failed to explain the patient’s symptoms… so we ultrasound:

On this PLAX view, we can see a large pericardial effusion. An effusion this large must be growing over a long period of time, as the pericardium needs time to expand in order to accommodate this much fluid. As expected, chart review showed that the patient had a large effusion documented several years ago.

Nonetheless, we need to know if this effusion is causing cardiac tamponade. So the first question is:

Is there RV collapse during diastole? Not really, you can appreciate the RV expanding as the MV leaflets open.

Case closed? Nope. Let’s go one step further.

We’ve heard of pulsus paradoxus by measuring blood pressure variation with respiration, but that requires an arterial catheter. Well, here is the ultrasonographic equivalent:

Placing spectral doppler gates at the ventricular side of the mitral valve on an A4CH view will give a curve with the mitral valve inflow (MVI) velocities. In a patient with a sinus rhythm, there should be little variation with respiration. However, in tamponade (even early tamponade), the increase in RV volume on inspiration results in leftward septal bulging, significantly decreasing the LV filling capacity, and hence, the MVI velocity. A difference of > 25% from MVI max to MVI min is consistent with tamponade physiology.

In this case, we have a difference of 27%, suggesting that there was indeed early tamponade physiology. With this information, this patient had a US guided pericardiocentesis in the ED, and was admitted for pericardial window with a good outcome.