Pulmonary Hypertension

Does this patient with pulmonary embolism need a PERT consult sooner or later? We typically are asked to notify PERT consult of all PE admissions, but which ones need to be seen more promptly? Certainly post-arrest or peri-arrest patients. Definitely those with clot-in-transit. But the majority of our patients will have PE on CT with or without CT evidence of pulmonary hypertension. An echo is always indicated and point-of-care echo in the ED can be a big help in deciding where these patients go and who knows about them.

Parasternal Long Axis (PLAX)

The PLAX view establishes the long axis of the heart but is generally not the optimal view to assess the right ventricle. Nonetheless, comparing the LA, Aortic root and RVOT, which should be roughly the same size, we note the RVOT is more than double the size of the other “chambers”.

Parasternal Short Axis (PSAX)

Chamber size comparison is best assessed with the PSAX view as was done here or the Apical 4 chamber (A4C) view. Here we again find a dilated right ventricle closest to the peaked footprint of the phased array probe. Not only is the RV dilated (greater than LV size), but right sided pressure is flattening the septum, giving the LV a characteristic “D-shaped” appearance. In A4C, TAPSE < 17mm is consistent with pulmonary hypertension.

Any patient with significant acute pulmonary hypertension will have a plethoric IVC. This IVC is > 3cm at the level of the hepatic veins with to and fro venous flow noted.

These findings clearly show pulmonary hypertension — the next step is to decide whether this hypertension is acute or chronic. Certainly factors other than echo findings will be important. What is the patient’s history, is there thrombus on CT, and are there any distinguishing features of their thrombus that suggest acute vs. chronic PE.

On Echo a few factors can be easily assessed:

• Right atrial size – RA > LA size suggests chronic pHTN.
• Right ventricular wall thickness
  • Measure the RV free wall at end-diastole, perpendicular to basal third, just below tricuspid valve. Best subxiphoid.
  • Chronic pHTN > 5 mm
  • Normal / Acute pHTN wall thickness:  $$≤ 5 mm
• More advanced techniques using spectral doppler assessment (TRPG, 60/60) are available as well.

For this patient with PE on CT and acute right ventricular failure, PERT and / or the ICU should see the patient sooner rather than later.