What is the recommended initial agent for blood pressure control in a patient with severe hypertension and symptoms suggestive of an acute aortic dissection, presenting with tearing epigastric pain radiating to the back?

Recommended Agent for Acute Aortic Dissection

Intravenous esmolol is the recommended first-line agent for this patient with suspected acute aortic dissection, given its ultra-short half-life (5-15 minutes) that allows rapid titration to achieve strict heart rate control before addressing blood pressure. 1, 2

Immediate Management Priority

Beta-blockade must be initiated before any vasodilator therapy to prevent reflex tachycardia and increased aortic wall shear stress (dP/dt), which can propagate the dissection. 1, 2

Why Esmolol Over Other Beta-Blockers

• Esmolol's ultra-short half-life (5-15 minutes) makes it the safest choice in acute aortic dissection, particularly if complications like bradycardia, hypotension, or organ malperfusion develop during treatment. 1
• The drug can be rapidly discontinued if hemodynamic instability occurs, unlike longer-acting agents. 3
• Esmolol administration: loading dose of 0.5 mg/kg over 2-5 minutes, followed by continuous infusion of 0.10-0.20 mg/kg/min. 1

Target Parameters

• Heart rate goal: ≤60 bpm (must be achieved first, before addressing blood pressure). 1, 2
• Systolic blood pressure target: 100-120 mmHg (achieved after adequate beta-blockade). 1, 2
• These targets reduce aortic wall stress by decreasing the force of left ventricular ejection. 1

Alternative: Labetalol

While labetalol (combined alpha- and beta-blocker) is FDA-approved for severe hypertension 4 and recommended for chronic thoracic aortic disease 5, it is less ideal than esmolol in acute dissection due to:

• Longer half-life (5.5 hours IV) compared to esmolol, limiting rapid reversibility if complications arise. 4
• Risk of profound cardiovascular compromise with continuous infusion, particularly in critically ill patients. 6
• Less precise heart rate control compared to pure beta-blockade. 7

Sequential Blood Pressure Management

Only after achieving heart rate control with esmolol should vasodilators be added if systolic BP remains >120 mmHg:

• Add intravenous sodium nitroprusside to achieve BP 100-120 mmHg. 1
• Never use vasodilators alone without prior beta-blockade, as this causes reflex tachycardia and increased dP/dt, worsening the dissection. 1, 2

Critical Monitoring Requirements

• Transfer immediately to intensive care unit with continuous ECG monitoring. 1, 2
• Place invasive arterial line for accurate blood pressure monitoring. 1
• Check blood pressure in both arms to exclude pseudo-hypotension from aortic arch branch obstruction. 1
• Monitor for signs of organ malperfusion (oliguria, neurological changes). 1

Evidence Quality

• The recommendation for beta-blockers in aortic disease carries Class I, Level C-EO evidence from ACC/AHA guidelines. 5
• Observational studies demonstrate improved survival with beta-blocker therapy in both Type A and Type B dissections. 5
• Clinical experience shows 82.5% of patients achieve lenient heart rate control (≤80 bpm) within 60 minutes of esmolol therapy, though strict control (≤60 bpm) is achieved in only 27.5%. 8

Common Pitfalls to Avoid

• Do not delay beta-blocker administration even in the presence of relative bradycardia—controlling dP/dt is crucial to prevent dissection propagation. 1
• Avoid dihydropyridine calcium channel blockers without beta-blockers, as they cause reflex tachycardia. 1
• Do not allow excessive blood pressure lowering that may compromise organ perfusion. 1
• Prepare for potential emergency surgical intervention, especially for Type A dissection (mortality 1-2% per hour without surgery). 2