Case # 16: The Smoking Gun

A 32 year-old woman with history of pleurisy and systemic lupus erythematosus presented to the emergency department with three weeks of shortness of breath and pleuritic chest pain, acutely worse one day prior to arrival.

She flew into San Diego three days prior to her hospital presentation. She became dyspneic when walking from her hotel bed to the bathroom. On review of systems, she did endorse 3 weeks of right lower leg cramping. She denied fever/chills, cough, back pain, or history of blood clots. She was tachypneic and speaking in short phrases upon arrival.

Vitals: T: 98.3, HR: 130, BP: 142/88, RR: 24, SpO2 97% on RA

A bedside ultrasound ECHO and lower extremity scan was preformed.  What do you see?

 

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RV strain gif
dvt gif 2

Answer and Learning Points

Answer

These ultrasound images show an apical 4 chamber and parasternal short view of the heart, as well as a right lower extremity DVT. The apical 4 chamber demonstrates right ventricular dilation with bowing of the septum into the left ventricle. The parasternal short illustrates “D sign” with right ventricular dilation and bowing/flattening of the interventricular septum leading to decreased left ventricular systolic function. Both views indicate right heart strain in the setting of likely pulmonary embolism. The right lower extremity showed a noncompressible right femoral vein, indicating DVT.

TPA was prepared and ready to give incase patient had worsening hemodynamic instability. She was fortuantley able to tolerate further imaging without HD compromise; CT angio confirmed the diagnosis of pulmonary embolism in bilateral main pulmonary arteries extending into all 5 lobes. Half dose TPA was administered and the patient was admitted to the ICU.

Learning Points

    • Identification of right ventricular dilatation on point-of-care echocardiography for the diagnosis of pulmonary embolism has a sensitivity of 50%, but a specificity of 98%1
    • Patients who present normotensive but have signs of cardiac dysfunction secondary to a PE are classified as submassive, and thrombolytic therapy should be considered2
    • When combining echocardiogram with lower extremity ultrasound, the sensitivity and specificity of cardiac US are 91% and 87%, respectively. Venous US shows a lower sensitivity 56%, but higher specificity 95% than cardiac. When cardiac and venous US are both positive the specificity increases to 100%, whereas when at least one was positive the sensitivity increased to 95.3
    • There is a broad differential of patients presenting to the emergency department with chest pain and shortness of breath. Point-of-care transthoracic cardiac ultrasound in the ED is an effective tool to promptly diagnose acute pulmonary embolism with right heart strain, and rapidly guide management.4,5 This patient with a history of lupus and pericarditis could have presented with cardiac tamponade, and ultrasound did show a small circumferential pericardial effusion, but did not show a collapsing right ventricle that would be expected in tamponade (instead, a dilated RV is seen).6
 

Author

Nicolas Kahl, MD. Emergency Medicine Resident. UCSD Department of Emergency Medicine.

Jessica Oswald, MD. Clinical Faculty, UCSD Department of Emergency Medicine. 

Sukhdeep Singh, MD. Clinical Faculty, UCSD Department of Emergency Medicine. Director of POCUS, El Centro Regional Medical Center.

References

  1. Dresden S, et al. Right Ventricular dilatation on bedside echocardiography performed by emergency physicians aids in diagnosis of pulmonary embolism. Ann Emerg Med; 2014 Jan; 63(1):16-24
  2. Malik Sonika et al. Advanced Management Options for Massive and Submassive Pulmonary Embolism. USC US Cardiology Review. 2016 Feb. 
  3. Nazerian P, et al.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
  4. Fields JM, et al. Transthoracic Echocardiography for Diagnosing Pulmonary Embolism: A Systematic Review and Meta-Analysis.J Am Soc Echocardiogr. 2017
  5. Kahl N, et al. Point-of-care Ultrasound Diagnosis of Pulmonary Embolism with Thrombus in Transit.Clin Pract Cases Emerg Med. 2019 Feb; 3(1): 11–12.
  6. Singh, S., et al., Usefulness of right ventricular diastolic collapse in diagnosing cardiac tamponade and comparison to pulsus paradoxus.Am J Cardiol, 1986. 57(8): p. 652-6.