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Difficulty: HardCardiovascular System

A 64-year-old man arrives at the emergency department via ambulance with sudden-onset, severe "tearing" chest pain that radiates to his back. His blood pressure is 215/115 mm Hg in the right arm and 175/95 mm Hg in the left arm. His heart rate is 118/min and regular. Physical examination reveals a new early diastolic decrescendo murmur at the right upper sternal border. An electrocardiogram shows sinus tachycardia and voltage criteria for left ventricular hypertrophy. Chest radiography demonstrates a widened mediastinum. The clinical team suspects an acute type A aortic dissection. Arrange the following steps in the correct order for the most appropriate management of this patient.

  1. 1Administer an intravenous beta-blocker (e.g., esmolol)
  2. 2Administer an intravenous vasodilator (e.g., sodium nitroprusside)
  3. 3Obtain a computed tomography (CT) angiography of the chest
  4. 4Consult cardiothoracic surgery for emergent operative repair

Answer

The correct sequence is: 1) Administer an intravenous beta-blocker, 2) Administer an intravenous vasodilator, 3) Obtain a computed tomography (CT) angiography, 4) Consult cardiothoracic surgery.
The management of an acute aortic dissection requires strict, stepwise coordination. The absolute first priority is medical stabilization (anti-impulse therapy). An intravenous beta-blocker is administered first to decrease heart rate (target < 60/min) and reduce left ventricular contractility (dP/dt), which lowers the shear stress on the aortic wall. Once the heart rate is controlled, an intravenous vasodilator is added if the systolic blood pressure remains elevated above the target of 100-120 mm Hg. Following hemodynamic stabilization, definitive imaging with CT angiography is performed to confirm the diagnosis and map the anatomy. Finally, because this patient has signs of ascending aorta involvement (Type A) indicated by the new aortic regurgitation murmur, emergent cardiothoracic surgical repair is required.

Step-by-Step Solution

1
Administer intravenous esmolol.
Heart rate and left ventricular contractility are reduced.
Decreases aortic wall shear stress and prevents dissection propagation; this must strictly precede vasodilators to prevent reflex tachycardia.
2
Administer intravenous sodium nitroprusside.
Systolic blood pressure is further reduced to a target of 100-120 mm Hg.
Provides additional blood pressure control to minimize aortic wall stress, only after the heart rate is adequately lowered.
3
Perform CT angiography of the chest.
The presence, type, and extent of the aortic dissection are confirmed.
Definitive imaging is required to differentiate a Stanford Type A from a Type B dissection and map the anatomy for surgical planning.
4
Consult cardiothoracic surgery.
The patient is taken for emergent surgical repair.
Type A aortic dissections (involving the ascending aorta, as suggested by the aortic regurgitation murmur) carry a high risk of fatal complications like rupture and require immediate surgery.

Key Concept

The stepwise management of acute aortic dissection (anti-impulse therapy sequencing).
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Topics

Cardiovascular System

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