Which medication reduces heart rate and contractility and is the drug of choice for aortic dissection?

Labetalol is the drug of choice for managing aortic dissection due to its unique pharmacological profile that effectively targets both heart rate and contractility. As a mixed alpha and beta-adrenergic blocker, labetalol decreases heart rate through its beta-blocking properties, which inhibit the effects of catecholamines on the heart. This reduction in heart rate is crucial in aortic dissection, as it diminishes the shear stress on the aortic wall and decreases the likelihood of further dissection.

Additionally, labetalol reduces contractility by blocking beta-1 receptors, which leads to decreased myocardial oxygen demand. This is particularly important in cases of aortic dissection, where the heart is under significant stress. The simultaneous alpha-blockade leads to vasodilation, which helps in managing blood pressure without significantly increasing heart rate, further protecting the aorta from undue pressure.

In contrast, while other medications like nicardipine may offer vasodilation, they do not effectively control heart rate and may result in reflex tachycardia. Nitroprusside is a potent vasodilator, but it can also lead to hypotension and does not provide the heart rate control necessary in aortic dissection. Phenylephrine primarily