He’s 40 years old and started experiencing chest pain while working out at the gym. What do you see?
“Wow! Your new ED is seriously the length of a football field!” the Critical Care Fellow exclaims. Happy that he wore his steps tracker today, he is eager to see just how many steps he logs walking up and down the beautiful, new hallways. You find yourself just a wee bit giddy as you gaze at the clean, new rooms and state of the art monitors and computer systems. Just as you start admiring the view from the brand new ambulance bay, your thoughts are interrupted by the lights and sirens of a unit screeching up your ramp.
“Hi Doc, we have a 40-year-old male we just picked up with severe chest pain. He looks pale and diaphoretic, and I don’t think it is all from the heat.” EMS is unloading a young, healthy-looking male from the back of their rig. You glance at the cardiac monitor and see that he is hypertensive, tachycardic, and definitely needs your immediate attention. There are no gross ischemic changes on the patient’s pre-hospital EKG, and it appears he is in sinus tachycardia.
The Critical Care Fellow happily follows you into the resuscitation bay with the ultrasound machine in tow. He is on day two of his ultrasound elective and is eager to learn the cool ultrasound tricks you have up your sleeve.
A quick history reveals that the patient was working out today at the gym when he started having worsening shortness of breath and chest pain. He stopped lifting weights and sat down to rest. His pain continued despite rest, and he remained diaphoretic despite drinking cold fluids and rinsing his face off with cold water. He has no other associated symptoms, but he states that he is scared and appears quite uncomfortable on exam.
Other than a recent workup for possible scleroderma and exercise-controlled hypertension, he has no other medical problems. He doesn’t take any medications regularly and doesn’t smoke, drink, or use drugs. As your nurses are putting in their IVs and drawing a rainbow of blood tubes for analysis, you and your fellow perform a bedside point-of-care cardiac ultrasound.
You obtain a parasternal long axis view of his heart to start (Image 1 below).
What do you see on your parasternal long axis view? What view would help you better delineate your findings?
Parasternal Long Axis View of the Heart
Your team watches you scan the heart, and the fellow begins to summarize what he sees so far. “There’s no significant pericardial effusion, and I don’t see any obvious wall motion abnormalities.”
“Good,” you reply. “What else do you see?” He pauses for a second before stating, “The RV and LV appear to be of normal size.”
“I agree. What do you think of the aortic outflow tract?” He and the rest of the team are staring intently at the screen as the fellow says, “I can’t really get a great view of that proximal aorta, but it looks like it may be dilated. I wish we could getter a better view of it.”
On cue, you take the phased array transducer, drop a dollop of gel on it, and place it just above the patient’s sternal notch. You aim the beam down towards the patient’s chest, behind the sternum and obtain Image 2 below.
Suprasternal View of the Aortic Arch
Your fellow’s eyes widen as you measure the aortic root diameter at 4.32 cm on your suprasternal view. After blood pressure and heart rate control to decrease the shearing forces on that dilated root, you get your cardiothoracic surgeons on board and obtain the CT angio of the patient’s chest as requested by your surgery colleagues. Sure enough, his CT confirms your ultrasound findings (Image 3 below), and the patient is whisked away for operative planning with your ICU team.
CT Angio of the Patient’s Chest Confirming a Dilated Aortic Root
Impressed by your ultrasound prowess, your fellow gears up the ultrasound machine and wheels it away to go help another patient in the department. You walk back towards your ambulance bay to take a peek at the gorgeous desert sunset breaking through the sky and think to yourself, “Yes, it is always about getting that perfect view.”
Pearls and Pitfalls: Performing an Ultrasound of the Proximal Aorta
- In patients who present with cardiopulmonary complaints, perform a point-of-care cardiopulmonary ultrasound during their initial assessment.
- The phased array or sector transducer has a small footprint that is great for visualizing the heart in a parasternal long axis view.
- In addition to assessing the heart for presence of a pericardial effusion, chamber size, contractility, and gross valvular movement, look at the patient’s aortic outflow tract and proximal aortic root on the parasternal long axis view.
- If you want a better look at the patient’s proximal aortic root and arch, try obtaining a suprasternal view.
- Have the patient lie supine with their head extended and chin up towards the ceiling. When you place the probe in the patient’s suprasternal notch, aim the beams down posteriorly behind the patient’s sternum.
- To obtain a long axis view of the proximal aorta, point the indicator towards the patient’s chin and fan left to right until you see the ascending and descending aorta.
- Rotate the probe clockwise towards the patient’s left if you want to obtain a short axis view of the proximal aorta.
- The suprasternal view will allow you to visualize and asses the patient’s proximal ascending aorta, aortic arch, proximal descending aorta, and left and right subclavian arteries.
- The proximal aorta should be < 3.0 cm in diameter. The suprasternal view can help you visualize dilation of the thoracic aorta and dissection flaps of the proximal aorta.
