Old McConnell Had a Fall

Written by: Dr. Haroon Karabay

Edited by: Dr. Joann Hsu

The case:

93 y/o f with PMH of HTN, HLD BIBEMS from home for shortness of breath.

  • Patient is A&Ox1 ( to self ) and reports that she had a fall an unknown time ago and is complaining of left lower leg pain.

  • Unable to obtain further history at the time.

  • Vitals: BP 121/78, T 36.8 C, SpO2 on RA 94%, RR 22

Physical Exam:

  • Saturating at 94% on 6L nasal cannula, mildly tachypneic

  • Clear lung sounds

  • Normal cardiac exam including RRR, no MRR.

  • No signs of external trauma

  • Bilateral distal lower extremity swelling and tenderness to palpation.

Given the vitals and physical exam you have increased concern for acute PE. You perform bedside cardiac point-of-care ultrasound (POCUS) and note the below finding in your apical 4-chamber view:

What do you see?

Background:

  • Right heart strain (more precisely, right ventricular strain) is a term given to describe the presence of right ventricular dysfunction in the setting of acute or chronic pathology.

  • Right heart strain often occurs because of pulmonary arterial hypertension (a chronic process).

  • One very common cause of acute right ventricular strain is pulmonary embolism.

  • The reported sensitivity and specificity of echocardiography in demonstrating right heart dysfunction are 56% and 42%, respectively.

  • In the emergency department, it may be difficult to definitively measure right heart strain but we can use bedside ultrasound to look for evidence of RV strain, particularly acute RV strain:

    • McConnell’s sign

    • Increased RV:LV ratio

    • Direct visualization of an RV thrombus

    • Abnormal septal motion (D sign seen in the parasternal short axis view)

    • Decreased TAPSE

    • Pulmonary arter mid-systolic notching

    • 60/60 sign

  • We will not go into all of these today, but there was one particular finding in this case: McConnell’s sign!

McConnell’s Sign

  • McConnell’s sign is defined as diffuse hypokinesis of the RV free wall with apical sparing. 

  • This is a very specific but not sensitive indicator of PE.

  • It used to be considered “the PE sign” however, consider it more of a supporting finding that should prompt you to pursue a definitive PE workup

  • Why does this happen? We don’t know for sure, but here are some theories:

    • RV ischemia or RV stunning/infarction due to nearby RCA occlusion supplying the RV free wall, with the separate LAD supplying the RV apex

    • Tethering of the RV apex to the adjacent/connected hyperdynamic LV, which makes it look like there is apical sparing

    • Bulging of the RV mid free wall during systole due to force redistribution

  • Let’s look at the 4 chamber view from this case again:

Notice the relatively hyperdynamic RV apex compared to the RV wall. Also the increased RV:LV ratio.

Here are examples of some of the other ultrasound findings in RV strain that we mentioned above. These images/videos were not taken from this particular case.

Increased RV:LV ratio, seen also in this case.

D sign: septal flattening seen in the parasternal short view due to increased pressures in the dilated RV, not seen in this case

Tricuspid regurgitation, which is a component of obtaining values for 60/60 sign

Thrombus!!

Back to our case:

  • CTPA obtained which was significant for pulmonary embolism within the distal aspects of the right pulmonary artery as well as within the left pulmonary artery branches. 

  • Patient was admitted to the medicine floor for IV anticoagulation therapy.  She was not a candidate for Catheter-directed thrombolysis or embolectomy.   

 

Happy scanning!

 

References: 

Kline JA. Venous Thromboembolism Including Pulmonary Embolism. In: Tintinalli JE, Ma O, Yealy DM, Meckler GD, Stapczynski J, Cline DM, Thomas SH. eds. Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 9e. McGraw-Hill Education; 2020. Accessed March 17, 2024. https://accessemergencymedicine.mhmedical.com/content.aspx?bookid=2353&sectionid=219641627 

Weerakody Y, Bell D, Saber M, et al.  Righ heart strain.  Reference article, Radiopaedia.org( Accessed on March 17th, 2024) https://doi.org/10.53347rlD-31600 

Reardon RF, Laudenbach AP, Heller K, M. Barnes R, Reardon L, Pahl T, J. Weekes A. Transthoracic Echocardiography. In: Ma O, Mateer JR, Reardon RF, Byars DV, Knapp BJ, Laudenbach AP. eds. Ma and Mateer's Emergency Ultrasound, 4e. McGraw-Hill Education; 2021. Accessed March 17, 2024. https://accessemergencymedicine.mhmedical.com/content.aspx?bookid=2966&sectionid=24999779 

Bickle I, Hacking C, Bell D, et al. Polo mint sign (venous thrombosis). Reference article, Radiopaedia.org (Accessed on 17 Mar 2024) https://doi.org/10.53347/rID-21056 

Singer, D. J., & Oropello, J. (2020). A hyperdynamic left ventricle on echocardiogram. Chest, 158(5). https://doi.org/10.1016/j.chest.2019.11.060  

Sosland, R. P., & Gupta, K. (2008a). McConnell’s Sign. Circulation, 118(15).  

Booth EM