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Aortic dissection
In aortic dissection the first question is whether the ascending aorta is involved: Stanford A — emergency surgery; Stanford B — medical treatment to lower heart rate and blood pressure, with endovascular repair only for complications.
Why it matters in the exam
The classic scenario is sudden, very severe, "tearing" chest pain radiating to the back in a hypertensive patient — sometimes with a blood-pressure difference between the arms, an aortic regurgitation murmur, a neurological deficit or a wide mediastinum on the X-ray. The question tests the test of choice (contrast CT; TEE in an unstable patient), the right order of drugs — first an IV beta-blocker and only then a vasodilator — and the treatment targets: heart rate below 60 and systolic pressure 100–120.
Risk factors are also asked: hypertension (the main one), Marfan syndrome, vascular Ehlers–Danlos, Loeys–Dietz, a bicuspid valve, Turner syndrome, cocaine, pregnancy and previous aortic surgery. Complications appear — tamponade, acute aortic regurgitation, infarction (usually inferior, when the dissection reaches the right coronary artery), stroke and organ ischaemia — and an important trap: a patient "with STEMI" who receives fibrinolysis while actually having a dissection.
A related subject is aortic aneurysm: surgery for the ascending aorta at 55 mm (50 in Marfan, sometimes 45 with risk factors), and for an abdominal aneurysm at 55 mm in men and 50 in women, or when it grows quickly.
Key points
- Stanford A (ascending): emergency surgery. Stanford B (descending): medical treatment, TEVAR if complicated.
- Presentation: sudden tearing pain to the back, arm-to-arm pressure difference, diastolic murmur, neurological deficit.
- Diagnosis by CT; TEE in an unstable patient.
- Drugs: beta-blocker first (rate below 60), then a vasodilator (systolic 100–120).
- No anticoagulants or fibrinolysis until dissection is excluded.
Summary table
| Type | Involvement | Treatment | Note |
|---|---|---|---|
| Stanford A | Ascending aorta, wherever the tear began | Emergency surgery | Very high mortality for every hour of delay |
| Uncomplicated Stanford B | Descending aorta only | Medical: beta-blocker, then a vasodilator | Imaging follow-up |
| Complicated Stanford B | Organ ischaemia, rupture, refractory pain or hypertension, rapid expansion | Endovascular repair (TEVAR) | — |
| Medical treatment | IV esmolol or labetalol, then nitroprusside as needed | Heart rate below 60, systolic 100–120 | No vasodilator before the beta-blocker |
| Diagnosis | Contrast CT; TEE in an unstable patient | A low D-dimer helps rule out at low risk | A normal chest X-ray does not exclude it |
In the full version for subscribers
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Sources
- ESC Guidelines for the management of peripheral arterial and aortic diseases, 2024 — Acute aortic syndromes
- ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease, 2022 — Acute aortic dissection
- Harrison's Principles of Internal Medicine, 21st edition (2022) — Diseases of the Aorta
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.