Case 8 - Lake of sorrows...

Author: Nish Cherian Reviewer: Nick Mani

A 50-year old male presents to ED with 1-2 weeks of feeling tired and more out of breath. In triage, he is noted to be in AF with a rapid ventricular response (rate of 130bpm), BP 110/70, SpO2 of 89% on room air.

POCUS shows:

Clip 1. PLAX

Clip 2. Subcostal

Clip 3. IVC

• What pathology is seen in Clips 1 & 2?

  Large pericardial effusion

• Which potential sonographic features of tamponade can be seen?

  A fixed and dilated IVC

  RV diastolic collapse can be appreciated in the PLAX view (scroll through the clip to see better).

  Other features of tamponade include:

  • RA systolic collapse

  • Mitral inflow velocity variation >25% (the sonographic equivalent of ‘pulsus paradoxus’)

• Which anatomical structure in the PLAX view can help in differentiating pleural vs pericardial fluid?

  The descending aorta in the parasternal long axis view is a useful anatomic landmark. Pericardial fluid lies anterior to the DA, whilst pleural fluid lies posterior to it.

• What normal structure can occasionally appear similar to pericardial fluid in the PLAX view?

  A pericardial fat pad. This usually lies anterior to the RV in the PLAX view which may be similarly hypoechoic to fluid and could be mistaken for a pericardial effusion.

  Importantly, pericardial fluid will accumulate in dependent regions first. Multiple views are always useful to help corroborate findings.

Case resolution

This patient initially had a CXR showing a cardiomegaly picture with signs of pulmonary congestion. POCUS completely altered management by diagnosing a large pericardial effusion. Whilst he remained haemodynamically stable, we can appreciate some early sonographic signs of tamponade. A pericardiocentesis was performed and the patient was admitted under Cardiology. He was ultimately diagnosed with a pericardial malignancy (an echogenic mass is seen in Clip 2 adherent to the RA).

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Appendix

Mitral inflow velocities are shown below. Whilst not the greatest quality of images, it doesn’t show any significant beat-to-beat variation. This is a more advanced skill but worthwhile learning for the more echo enthusiastic people out there!