PoCUS – Dilated Aortic Root

Medical Student Clinical Pearl

James Kiberd

Class 2019 Dalhousie Medicine

Reviewed and Edited by Dr. David Lewis


Case:

A 66 year-old female presented to the Emergency Department with shortness of breath and back pain. She had a known dilated aortic root, which was being followed with repeat CT scans. Given the nature of her presenting complaint, a PoCUS was performed to assess her aorta.

 

 

 

Long Axis Parasternal View:

PoCUS for Cardiac imaging has been studied in the acute care setting; focusing on the assessment for pericardial effusion, chamber size, global cardiac function, and volume status, and cardiac arrest.1

In the setting of acute aortic dissection, further evaluation is often recommended depending on the practitioner’s skill level.2 There have been case reports where ultrasound has been used to assess both Type A and Type B aortic dissections.3–5

In order to assess the aortic root, have the patient in a supine position. Either the phased array or the curvilinear probe can be used depending on examiner’s preference. The probe should be positioned with the marker towards the patient’s right shoulder on the anterior chest to the left of the patient’s lower left sternal border. By tilting the transducer between the left shoulder and right hip, long axis views are obtained at different levels with the goal of identifying four main structures; the aorta, the left atrium, and the right and left ventricles. The parasternal long axis view of our patient is shown in Figure 1, where her aortic root measured 3.83cm.

 

Figure 1: Parasternal Long Axis View of Heart: Patient’s root diameter was found to be 3.83cm.

More generally, this view can be used to assess left ventricular contractility and the presence of pericardial effusion, which were not present in this patient. She went on to have a confirmatory CT scan where her aortic root was found to be unchanged from her last scan and was 3.8 cm in diameter as assessed by PoCUS.

In Summary:

Although not rigorously studied to assess aortic root dilatation at the bedside, we present a case where PoCUS was reliable in the assessment of the aortic root. There have been other cases of aortic dissection identified by ultrasound in the emergency department setting, however confirmatory studies (either CT scan or formal echocardiography) are still recommended.


References:

  1. Labovitz AJ, Noble VE, Bierig M, et al. Focused cardiac ultrasound in the emergent setting: A consensus statement of the American society of Echocardiography and American College of Emergency Physicians. J Am Soc Echocardiogr. 2010;23(12):1225-1230. doi:10.1016/j.echo.2010.10.005.
  2. Andrus P, Dean A. Focused cardiac ultrasound. Glob Heart. 2013;8(4):299-303. doi:10.1016/j.gheart.2013.12.003.
  3. Perkins AM, Liteplo A, Noble VE. Ultrasound Diagnosis of Type A Aortic Dissection. J Emerg Med. 2010;38(4):490-493. doi:10.1016/j.jemermed.2008.05.013.
  4. Bernett J, Strony R. Diagnosing acute aortic dissection with aneurysmal degeneration with point of care ultrasound. Am J Emerg Med. 2017;35(9):1384.e3-1384.e4. doi:10.1016/j.ajem.2017.05.052.
  5. Kaban J, Raio C. Emergency department diagnosis of aortic dissection by bedside transabdominal ultrasound. Acad Emerg Med. 2009;16(8):809-810. doi:10.1111/j.1553-2712.2009.00448.x.
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