Type A aortic dissection with malperfusion — FFICM MCQ

Correct answer: A — Start intravenous beta-blockade before vasodilator titration

The correct answer is A, start intravenous beta-blockade before vasodilator titration. In acute type A aortic dissection with tachycardia and hypertension, the priority is to reduce aortic wall shear stress by lowering both heart rate and blood pressure, and heart rate control must come first. If a vasodilator such as sodium nitroprusside is given without prior rate control, the resulting reflex tachycardia increases dP/dt (rate of aortic wall stress rise) and can propagate the dissection. Intravenous beta-blockers (labetalol or esmolol are standard choices) reduce contractility and heart rate, after which a vasodilator can be titrated safely to target a systolic BP of 100 to 120 mmHg while awaiting definitive surgical repair. Why the other options are wrong: E. Start sodium nitroprusside without rate control: vasodilating without prior beta-blockade produces reflex tachycardia and increased shear stress on the dissected aortic wall, risking propagation or rupture. C. Give thrombolysis for presumed stroke: the arm weakness reflects malperfusion from the dissection extending into the brachiocephalic artery, not primary ischaemic stroke; thrombolysis in dissection is contraindicated and can precipitate catastrophic haemorrhage or rupture. D. Maintain systolic BP above 180 mmHg: this is the opposite of the required target; sustained hypertension increases aortic wall tension and risk of rupture or extension, the goal is systolic BP 100 to 120 mmHg. B. Insert an intra-aortic balloon pump: IABP has no role in type A dissection management and its diastolic augmentation and counterpulsation could worsen aortic wall stress; the definitive treatment is emergency surgical repair, not mechanical circulatory support. Key point: In aortic dissection always control heart rate with intravenous beta-blockade before or alongside vasodilators, never vasodilate first, to avoid reflex tachycardia worsening aortic shear stress.

Reference: European Society of Cardiology 2014 Guidelines on the Diagnosis and Treatment of Aortic Diseases (endorsed for UK practice via FICM/ICS aortic dissection care pathways), Section on medical therapy of acute aortic syndromes: beta-blockade to reduce heart rate precedes vasodilator titration to target systolic BP 100-120 mmHg. https://academic.oup.com/eurheartj/article/35/41/2873/2293375