For a patient suspected of having an aortic dissection, which intervention is appropriate?

• A. Administer a calcium channel blocker
• B. Administer a nitroprusside infusion
• C. Administer a beta-blocker to control the heart rate
• D. Initiate high-dose diuretics

Answer: (C)

When aortic dissection is suspected, the priority is to minimize stress on the aortic wall by quickly lowering heart rate and systolic blood pressure. A beta-blocker is the best choice because it directly slows the heart rate and reduces contractility, which lowers the rate of rise of aortic pressure (dP/dt) and decreases shear forces on the vessel wall. This helps prevent propagation of the dissection and reduces the risk of rupture. Targeting a heart rate around 60 bpm and a systolic BP of about 100–120 mmHg guides therapy.

If blood pressure remains high after heart rate control, a vasodilator can be added to drop BP, but it should be used in combination with a beta-blocker because vasodilators alone can trigger reflex tachycardia and worsen the dissection. Nitroprusside lowers BP rapidly but can cause reflex tachycardia, which is why it’s not used first-line without beta-blockade. A calcium channel blocker might be considered if beta-blockers are contraindicated, but it does not address heart rate and dP/dt as reliably or promptly as a beta-blocker. High-dose diuretics are not appropriate acutely because reducing preload can compromise perfusion in a patient who may already be hemodynamically unstable.