By Nicole Guerrero, Gagandeep Singh
42 y/o M PMH of HTN, COVID 3 weeks ago, and PE not on AC presenting with SOB 3 weeks, worsening exertional SOB for 2 to 3 days with diffuse chest pain.
Vitals: Tachycardia to 130s, hypoxia to 85%, and borderline low BP 113/80.
Physical exam: Patient diaphoretic, ill appearing, and with increased WOB. Lungs CTAB
ECG: Sinus tachycardia with S1T3Q3 pattern
POCUS interpretation: Cardiac images seen in the above show multiple findings concerning right heart Strain. RV dilation can be seen best in the apical 4 chamber view ( image 1) Normally the RV:LV ratio in diastole is approximately 0.6:1. In our image the RV is noticeably bigger than
the LV. RV dilation can also be appreciated in parasternal long view ( image 2), the RV at the top of the screen is larger than the aortic outflow and left atria. The RV should be roughly the same size as the aorta and LA in this view with a 1:1:1 ratio. RV >Ao/LA is a sign of right heart strain. Leftward bowing of the interventricular septum known as septal flattening/bowing is also seen in apical 4 chamber view (image 1) and in the parasternal short view (image 3). In the parasternal short view the LV looks like a D secondary to increase RV pressure leading to septal flattening/bowing. This finding is known as D-sign.
POCUS Pearls: The apical 4 chamber view is an high yield cardiac POCUS view in the evaluation for right heart strain. In addition to the two findings discussed above, the apical 4 chamber may also show an akinetic RV free wall that spares the apex ( McConnell’s sign). In our apical 4 chamber view, McConnell’s sign may be present but more difficult discern. In patients with suspected PE, McConnell’s sign is the only sonographic sign considered to be specific for acute right heart strain. If the apical 4 chamber view is technically difficult to obtain, a combination of the parasternal long and short view can provide similar information in the evaluation of right heart strain.
Case Continued...
Given these findings of right heart strain, we had a high suspicion for submassive/massive pulmonary embolism in our patient and started empiric treatment with heparin prior to obtaining CTA chest, PE study. He was also placed on HFNC. PERT team was activated, TPA was considered given that the patient subsequently became hypotensive requiring Levophed. Ultimately, given the patient’s good response to HFNC and Levophed. TPA was held and urgent CT PE was obtained that showed extensive b/l pulmonary emboli involving left and right pulmonary arteries. Decision was made for the patient to undergo thrombectomy. Patient underwent a successful bilateral thrombectomy and was discharged home on DOAC 3 days after initial presentation to ED.
Nicole’s Takeaways:
Risk stratification of patients with acute PE allows for optimal management choices
TPA is indicated in the setting of massive PE (cardiac arrest, SBP <90 for 15 minutes, SBP drop > 40 from baseline for >15 minutes, bradycardia <40 with shock, vasopressor required to maintain BP) in patients with no absolute contraindications to thrombolytic therapy.
Thrombectomy (or other interventional treatment) should be considered in patients high-risk submassive PE ( RV strain and Elevated Troponin/BNP)
Resources:
Dudzinski DM, Giri J, Rosenfield K. Interventional Treatment of Pulmonary Embolism. Circ Cardiovasc Interv. 2017 Feb;10(2):e004345. doi: 10.1161/CIRCINTERVENTIONS.116.004345. PMID: 28213377.
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