Q&A Medicine>>>>>Cardiology
Question 57#

A young man with Marfan syndrome is brought in by paramedics with sharp chest pain that radiates to his back. Shortly after the pain started, he developed left-sided weakness. The chest pain progressed and an ambulance was called. The initial blood pressure recorded by paramedics on the right arm was 78/54 mmHg, but a reading from the left arm shows 114/74 mmHg. An ECG is performed and shows ST elevations in the anterolateral leads. There is widening of the mediastinum on chest x-ray.

Which of the following is the most likely underlying diagnosis?

a. Myocardial infarction
b. Aortic dissection
c. Stroke
d. Acute aortic regurgitation

Correct Answer is B

Comment:

Aortic dissection. The most important risk factor for aortic dissection in the general population is hypertension; however, there is a high incidence in patients with connective tissue disease (e.g., Marfan and Ehlers–Danlos syndromes). Sharp chest pain radiating to the back is the first clue to this diagnosis. Other symptoms may occur based on which arteries are occluded by the dissected flap. This patient has a dissection of the ascending aorta, since he has symptoms/signs involving the left coronary artery (ST elevations in the anterolateral distribution) and brachiocephalic artery (affecting the right coronary artery leading to symptoms of stroke and the right subclavian artery leading to a decrease in systolic blood pressure >20 mmHg in the right arm compared to the left). Other potential manifestations not seen in this patient are cardiac tamponade and Horner syndrome (from compression of the superior cervical ganglion). Dissections involving the proximal aorta require immediate surgical intervention.

(A, C, D) All of these diagnoses are a result of the patient’s aortic dissection, but are not the underlying (primary) diagnosis. ACS may occur during an aortic dissection as a result of involvement of one or more coronary arteries, and stroke can occur with involvement of the carotid arteries. Aortic regurgitation is common in patients with Marfan syndrome, and this can also occur as a result of a dissection in the ascending aorta. In either situation, it is not the primary diagnosis.