“POCUS In Pulmonary Embolism” From EM Quick Hits 65

Here is a great list of YouTube videos on POCUS for Pulmonary Embolism.

Today, I review, link to, and excerpt from Emergency Medicine Cases‘ “POCUS In Pulmonary Embolism” From EM Quick Hits 65.*

*Helman, A. MacArthur, M. Chernoff, I. Rosenberg, H. Segeren, S. Long, B. Booth, K. EM Quick Hits 65 – Occipital Nerve Block, PoCUS in Pulmonary Embolism, Myelopathy, Team Resuscitation, Incidental Neutropenia, Peer Programs. Emergency Medicine Cases. June, 2025. https://emergencymedicinecases.com/em-quick-hits-june-2025/. Accessed August 6, 2025.

All that follows is from the above resource.

Play Podcast

Ian Chernoff on the role of POCUS in patients with pulmonary embolism (10:25 – 29:10)

PoCUS in the diagnosis and risk stratification of pulmonary embolism

This is a companion podcast segment to our 2-part podcast on Management of Pulmonary Embolism: Management of Intermediate Risk PE, and Management of High Risk PE

POCUS may offer high-yield prognostic information for intermediate-risk PE patients with CT, as well as diagnostic information for high-risk PE patients who are too unstable for CT.

All basic PoCUS views have findings that support the diagnosis of RV strain in PE:

• Subcostal: IVC distention
• Parasternal long axis: D-sign and RV enlargement

• Apical 4-Chamber View (most useful):
  • TAPSE <1.6cm (abnormal longitudinal RV contraction): Measured using M-mode placed through the lateral tricuspid annulus.
  • RV free wall hypokinesis (dysfunctional radial RV contraction): More sensitive than TAPSE in detecting RV strain.
  • RV to LV ratio ≥1

Advanced Signs:

• Paradoxical septal motion (intraventricular septum bowing into the LV).
• McConnell’s Sign (RV free wall akinesis with apical sparing): 97-99% specificity but found in ~25% of patients with PE.
  • Present in acute PE but not in chronic RV pathologies e.g. pulmonary hypertension.
  • Caveat: can also be present in RV infarction.

• Clot in transit through the RV or RA (rare but diagnostic).
• Pulmonary artery acceleration time <60ms (via pulse wave doppler on parasternal short axis view, part of the “60/60 rule”).
  • In acute PE, blood flow within the pulmonary artery reaches peak velocity quickly (<60ms) as the RV has yet to accommodate to the acute increase in RV afterload.
  • In chronic PE, pulmonary artery acceleration time is slower as the RV accommodates the increased outflow resistance through RV hypertrophy.
• Presence of early systolic notching (via pulse wave doppler on parasternal short axis view).
  • Presence of an acute PE causes a characteristic early retrograde pressure wave or “early systolic notching” as blood entering the pulmonary artery strikes and rebounds off the PE obstruction.
  • In pulmonary hypertension or lower risk/distal PE, the rebound pressure wave returns in a delayed fashion, causing “mid systolic notching.”
• Tricuspid regurgitation gradient <60mmHg (via colour and continuous wave doppler on multiple views, part of the “60/60 rule”).
  • In chronic PE/pulmonary hypertension the RV accommodates via hypertrophy and produces higher peak TR gradients as compared to a non-hypertrophic RV in an acute PE which struggles against the acute increase in RV afterload.

Approach:

• Intermediate risk PE: PoCUS improves the detection of RV strain as compared to CTPA alone (Dudzinski et al. 2017).
• High risk PE: PoCUS is highly sensitive in revealing PE as a cause of a patient’s peri-arrest state.
  • Up to 100% specificity for PE as the cause of shock if both cardiac and leg ultrasound were positive for signs of RV strain and DVT respectively (Nazerian et al. 2018).
  • ESC guidelines support immediate thrombolysis without further testing if there is echocardiographic evidence of RV dysfunction in an unstable patient (Konstantinides et al. 2020).
• Distinguishing acute vs. chronic RV dysfunction is key. For example:
  • RV wall thickening >5mm on subcostal/parasternal long axis view = chronic
  • Identifying McConnell’s sign/clot in transit, early systolic notching, meeting the “60/60 rule” = acute

Pitfalls:

• Foreshortening of the RV on apical view can lead to overestimation of RV size.
  • If the entire heart appears rounder/broader (LV not elliptical), move the probe one interspace caudally and laterally.
• Mismatch between POCUS and CT findings with clinical picture? Re-evaluate.

Bottom Line: In intermediate risk PE, PoCUS may help risk stratify. In high-risk or crashing patients PoCUS can be diagnostic and guide immediate reperfusion decisions.

References

1. Fields JM, Davis J, Girson L, Au A, Potts J, Morgan CJ, Vetter I, Riesenberg LA. Transthoracic Echocardiography for Diagnosing Pulmonary Embolism: A Systematic Review and Meta-Analysis. J Am Soc Echocardiogr. 2017 Jul;30(7):714-723.e4. doi: 10.1016/j.echo.2017.03.004. Epub 2017 May 9. PMID: 28495379.
2. Dudzinski DM, Hariharan P, Parry BA, Chang Y, Kabrhel C. Assessment of Right Ventricular Strain by Computed Tomography Versus Echocardiography in Acute Pulmonary Embolism. Acad Emerg Med. 2017 Mar;24(3):337-343. doi: 10.1111/acem.13108. PMID: 27664798.
3. Nazerian P, Volpicelli G, Gigli C, Lamorte A, Grifoni S, Vanni S. Diagnostic accuracy of focused cardiac and venous ultrasound examinations in patients with shock and suspected pulmonary embolism. Intern Emerg Med. 2018 Jun;13(4):567-574. doi: 10.1007/s11739-017-1681-1. Epub 2017 May 24. PMID: 28540661.
4. Konstantinides SV, Meyer G, Becattini C, Bueno H, Geersing GJ, Harjola VP, Huisman MV, Humbert M, Jennings CS, Jiménez D, Kucher N, Lang IM, Lankeit M, Lorusso R, Mazzolai L, Meneveau N, Ní Áinle F, Prandoni P, Pruszczyk P, Righini M, Torbicki A, Van Belle E, Zamorano JL; ESC Scientific Document Group. 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS). Eur Heart J. 2020 Jan 21;41(4):543-603. doi: 10.1093/eurheartj/ehz405. PMID: 31504429.