Which agent is a calcium channel blocker used to control blood pressure in aortic dissection?

Which agent is a calcium channel blocker used to control blood pressure in aortic dissection?

• A. Nicardipine
• B. Nitroprusside
• C. Labetalol
• D. Hydralazine

Answer: (A)

Controlling blood pressure quickly and precisely is crucial in acute aortic dissection to lessen the force of blood flow against the torn aorta. After getting heart rate and contractility under control, you need a medication that lowers afterload without overly depressing heart function. A calcium channel blocker given IV fits this need because it causes arterial dilation and reduces systemic vascular resistance in a titratable way, allowing careful BP lowering with good control in the ICU. Nicardipine is a preferred option for this role because it provides gradual, predictable BP reduction without the significant myocardial depression seen with some other agents. Other choices don’t fit as the calcium channel blocker in this scenario: nitroprusside is a powerful vasodilator but often triggers reflex tachycardia, which can worsen dissection unless used with a beta-blocker; hydralazine is a less predictable direct vasodilator with reflex effects; labetalol is a beta-blocker (with alpha-blockade) and not a calcium channel blocker, though it is used to lower BP in dissection as well.

Controlling blood pressure quickly and precisely is crucial in acute aortic dissection to lessen the force of blood flow against the torn aorta. After getting heart rate and contractility under control, you need a medication that lowers afterload without overly depressing heart function. A calcium channel blocker given IV fits this need because it causes arterial dilation and reduces systemic vascular resistance in a titratable way, allowing careful BP lowering with good control in the ICU. Nicardipine is a preferred option for this role because it provides gradual, predictable BP reduction without the significant myocardial depression seen with some other agents.

Other choices don’t fit as the calcium channel blocker in this scenario: nitroprusside is a powerful vasodilator but often triggers reflex tachycardia, which can worsen dissection unless used with a beta-blocker; hydralazine is a less predictable direct vasodilator with reflex effects; labetalol is a beta-blocker (with alpha-blockade) and not a calcium channel blocker, though it is used to lower BP in dissection as well.