Aortic Dissection

Vascular Torn aortic wall

A tear in the inner lining of the body's main artery, letting blood split the wall apart — a time-critical emergency.

Educational summary only — not medical advice, and no substitute for assessment by a clinician. Diagrams are simplified illustrations.

High-pressure blood rips through the inner lining and splits the aortic wall, carving a dangerous 'false channel' alongside the true one.

Overview

The aorta is the large artery that carries blood out of the heart to the whole body. In an aortic dissection, the inner lining of the aorta tears and high-pressure blood is forced into the wall itself, splitting its layers apart. It is uncommon but extremely dangerous, and survival depends on recognising it fast.

How the system normally works

The aortic wall has three layers — a smooth inner lining (intima), a strong muscular-elastic middle (media), and a tough outer coat (adventitia). Together they withstand the powerful pulse of blood leaving the heart with every beat.

What goes wrong

If the inner lining tears — usually where the wall is already weakened by years of high blood pressure or a connective-tissue disorder — blood is driven between the layers, carving a false channel. This has three dangers: the thinned outer wall can rupture (catastrophic bleeding); the flap can block branch arteries feeding the heart, brain, kidneys or limbs; and it can damage the aortic valve. The tear tends to extend along the vessel, which is why pain can migrate.

Cross-section diagram of an artery wall's three layers with a tear in the inner lining letting blood split into the middle layer. — The artery wall has three layers. A tear in the inner lining lets blood burrow into the middle layer, splitting it into a true and a false channel.

Symptoms and why they happen

Sudden, severe chest or upper-back pain, classically tearing or ripping — the wall splitting.
Pain that moves (e.g., front to back) as the tear extends.
A difference in pulse or blood pressure between the two arms — a branch artery compromised.
Fainting, stroke-like symptoms, or signs of organ damage — blocked branches.

Causes and risk factors

Long-standing high blood pressure (by far the most common)
Connective-tissue disorders (e.g., Marfan syndrome)
A pre-existing aortic aneurysm or bicuspid aortic valve
Cocaine or stimulant use; major chest trauma
Older age and being male

How it's diagnosed

Speed is everything. A CT angiogram of the chest and abdomen is the usual test and shows the tear and its extent; a bedside or trans-oesophageal echocardiogram can be used for unstable patients. The location (type A vs B) determines treatment.

Diagram comparing type A aortic dissection involving the ascending aorta and type B involving only the descending aorta. — Location decides treatment: a tear involving the ascending aorta near the heart (type A) is a surgical emergency; one limited to the descending aorta (type B) is often managed with medication.

Treatment and management

Blood pressure and heart rate are urgently lowered with medication to reduce stress on the wall. A dissection involving the ascending aorta (type A) is a surgical emergency to replace the torn segment. A dissection limited to the descending aorta (type B) is often managed with intensive blood-pressure control, with surgery or a stent reserved for complications.

Possible complications

Rupture, stroke, heart attack, kidney or bowel ischaemia, and aortic valve failure — any of which can be fatal, making rapid treatment essential.

Prevention and outlook

The best prevention is controlling blood pressure and, in those with known aneurysms or genetic risk, regular imaging and timely surgery. Outlook depends heavily on type and how quickly treatment is started.

When to seek emergency care

Sudden tearing or ripping chest/back pain — call emergency services immediately; do not wait.
Chest pain with fainting, stroke symptoms, or a cold/pulseless limb.