Rosh Emergency Medicine Practice Test

In a patient experiencing acute shortness of breath and upper back pain, what is the single most important predisposing risk factor for an aortic dissection?

1. Chronic aortic aneurysm

2. Diabetes mellitus

3. Hypertension

4. Smoking

The correct answer is: Hypertension

The most significant predisposing risk factor for an aortic dissection is hypertension. Chronic high blood pressure can cause damage to the aortic wall over time, leading to structural weaknesses. This deterioration increases the risk of dissection, where the layers of the aorta split apart, which can result in severe complications, including death. Hypertension affects the aorta by promoting changes in the vessel wall, such as fibroelastic degradation and medial necrosis, which can predispose an individual to the risks associated with aortic dissection. In fact, studies consistently show a strong correlation between untreated or poorly managed hypertension and the incidence of aortic dissection. While chronic aortic aneurysm, diabetes mellitus, and smoking are also important cardiovascular risk factors, they do not exhibit the same level of direct and immediate correlation to aortic dissection as hypertension does. Chronic aortic aneurysm may be a consequence of hypertension rather than an independent risk factor. Diabetes and smoking can contribute to overall cardiovascular disease but are less specifically linked to the mechanism of aortic dissection compared to the impact of sustained high blood pressure on the aorta's structural integrity.