A 54-year-old female with a history of hypertension and prior cocaine abuse presented to our ED with sudden onset, severe substernal, chest pain. The patient was given 1 mg of hydromorphone and reported resolution of the chest pain, but then developed epigastric abdominal pain. She denied having pain like this previously. It was not associated with any SOB, cough, fever, chills, or diaphoresis. While in the ED, she developed several episodes of non-bloody diarrhea and emesis.
Initial vital signs: HR 79, BP 112/54, SpO2 100% on RA, T 98.6 °F
The ED team initiated a work up for both cardiac and biliary causes of the pain with a CBC, chemistry, troponin, LFTs, Lipase, CXR, EKG, and bedside US of the gallbladder.
All labs came back unremarkable. EKG showed no clear pattern of injury although did have some non-specific ST-depression. CXR was unremarkable as was the GB ultrasound.
The patient’s BP rose to 218/99 throughout her course in the ED with the other vital signs remaining stable.
A new team took over the care of the patient and decided to perform a bedside cardiac ultrasound.
You can see that the left ventricular walls look thick consistent with LVH. The heart also looks hyperdynamic. This can be appreciated by looking at the walls of the LV. See how they almost touch during systole.
Given the hypertension, the providers also decided to do a suprasternal view to look at the aortic arch for dissection. This view can be obtained by having the patient lie supine. We prefer to put a towel or something behind the shoulders.
The phased-array transducer is then placed in the sternal notch with the transducer marker aimed toward the patients left scapula.
This should give you a view of the aortic arch with its three branches; the brachiocephalic, left common carotid, and left subclavian arteries. Here is an example of an image that might be obtained:
Here is a drawing of the basic structures you are seeing in the ultrasound clip:
You can see in these clips that there is a flap in the lumen of the aortic arch. The providers were not sure if this was artifact or a real dissection flap so they continued to image the aorta. Here is another atypical view of the arch:
From this view, the flap is still present making it highly likely that this was an aortic dissection. Immediate CT scan confirmed a Type A aortic dissection propagating from the ascending aorta down to the iliac arteries.
In retrospect, it is easy to see that this was a case of aortic dissection, but to the ED team, dissection was not high on the differential. Bedside ultrasound helped cinch this diagnosis and it could have diagnosed the dissection right away if it were to have been performed earlier.
TTE has been shown to have a sensitivity of 59.3-79% for detection of thoracic aortic dissection and a specificity of 83-100% in various studies. These studies usually use two criteria to rule in dissection, either dilation of the aorta (>40 mm in the ascending aorta and >35 mm in the aortic arch) or presence of an intimal flap.
1) Consider bedside cardiac ultrasound in any undifferentiated thoraco-abdominal pain
2) You should not rely on TTE to rule out aortic dissection, but if you see an intimal flap you can quickly and reliably rule in dissection.
- Khandheria BK, Tajik AJ, Taylor CL, et al. Aortic dissection: review of value and limitations of two-dimensional echocardiography in a six year experience. J Am Soc Echocardiogr 1989; 2:17-24
- Nienaber CA, von Kodolitsch Y, Nicolas V, et al. The diagnosis of thoracic aortic dissection by noninvasive imaging procedures. N Engl J Med 1993; 328:1-9
- Roudaut RP, Billes MA, Gosse P, et al. Accuracy of M-mode and two-dimensional echocardiography in the diagnosis of aortic dissection: an experience with 128 cases. Clin Cardiol 1988; 11:553-62