Aortic Dissection

What happens in aortic dissection

The aorta carries blood from the heart through the chest and abdomen. Its wall has three layers. In a dissection, a tear in the innermost layer allows blood under high pressure to enter the middle layer and split it apart, creating a false channel (false lumen) alongside the true one.

The dissection can extend along the aorta within seconds and cause harm in several ways:

• rupture through the outer wall, causing massive internal bleeding
• blocking branch arteries to the heart, brain, spinal cord, kidneys, gut or limbs
• damaging the aortic valve, causing it to leak
• bleeding into the sac around the heart (cardiac tamponade), which stops the heart filling

Types of aortic dissection

The older DeBakey system uses types I, II and III. Doctors also describe dissection as acute (under 2 weeks), subacute or chronic.

Symptoms

• sudden, severe pain in the chest, upper back between the shoulder blades, or abdomen
• pain described as tearing, ripping, stabbing or sharp, at its peak from the start
• pain that moves or spreads, for example from chest to back or down to the belly and legs
• fainting or near-fainting
• shortness of breath
• sweating, pale skin, a fast weak pulse
• a difference in blood pressure or pulse between the arms
• stroke symptoms: face droop, weakness, slurred speech
• cold, painful, numb leg or arm
• paralysis of the legs if spinal arteries are blocked
• belly pain with vomiting if gut arteries are affected

Some people, especially older adults and people with diabetes, have little or no pain and present with fainting, stroke or breathlessness. This makes the diagnosis easy to miss.

Aortic dissection vs heart attack

Telling dissection apart from a heart attack matters because blood thinners and clot-busting drugs used for heart attacks can be fatal in dissection.

Causes and risk factors

• High blood pressure: the most important risk factor, present in most people with type B dissection
• Existing aortic aneurysm or enlargement
• Genetic connective tissue disorders: Marfan syndrome, Loeys-Dietz syndrome, vascular Ehlers-Danlos syndrome and Turner syndrome
• Bicuspid aortic valve and coarctation of the aorta
• Family history of aortic aneurysm or dissection
• Cocaine and amphetamine use, which cause sudden blood pressure spikes
• Heavy weightlifting, especially in people with an enlarged aorta
• Pregnancy, mainly in the third trimester or after delivery in women with underlying aortic disease
• Previous heart or aortic surgery
• Inflammatory conditions affecting the aorta, such as giant cell arteritis
• Age 60 to 80, and male sex

Diagnosis

Aortic dissection is diagnosed in the emergency department:

• CT angiography: the main test. It shows the tear, the false lumen, which branches are involved, and whether it is type A or B.
• Transesophageal echocardiogram (TEE): an ultrasound through the esophagus, useful in unstable patients or during surgery.
• Bedside heart ultrasound: can show fluid around the heart or a leaking aortic valve.
• MRI: for stable patients and long-term follow-up.
• ECG and blood tests, including troponin and D-dimer, to help separate it from heart attack and pulmonary embolism.

Treatment

Immediate medical treatment

• Lowering heart rate and blood pressure with IV beta blockers, then other IV medicines if needed. Targets are typically a heart rate around 60 and systolic pressure 100 to 120 mm Hg, to reduce stress on the aortic wall.
• Strong pain relief.
• Intensive care monitoring.

Type A

Emergency open-heart surgery replaces the damaged ascending aorta with a synthetic graft, sometimes with repair or replacement of the aortic valve. Without surgery, the death rate rises by about 1% to 2% for every hour in the first 48 hours.

Type B

Uncomplicated type B dissection is treated with medicines to control blood pressure and heart rate, with close imaging follow-up. Complicated type B dissection (rupture, blocked organ or limb blood flow, uncontrolled pain or rapid enlargement) is treated with thoracic endovascular aortic repair (TEVAR), a stent graft inserted through the groin arteries to cover the entry tear.

Complications

• aortic rupture and death
• stroke and spinal cord injury with paralysis
• heart attack and aortic valve regurgitation
• kidney failure
• gut ischemia
• limb ischemia
• later aneurysm formation in the weakened aorta

Outlook and life after aortic dissection

Acute aortic dissection has a high death rate without treatment, especially type A. With prompt surgery, most type A patients survive to leave the hospital. Survivors need lifelong care:

• strict blood pressure control, usually with beta blockers
• CT or MRI scans at regular intervals, often at 1, 3, 6 and 12 months, then yearly
• avoiding heavy lifting and straining, and stimulant drugs
• genetic testing and screening of first-degree relatives when a hereditary cause is suspected

Prevention

• Control blood pressure. This is the single most effective measure.
• Do not smoke and avoid cocaine and amphetamines.
• If you have Marfan syndrome, a bicuspid valve, a known aortic aneurysm or a strong family history, keep up with imaging and follow advice on when preventive surgery is needed.

Frequently asked questions

What does an aortic dissection feel like?

Most people describe sudden, severe, tearing or ripping pain in the chest or between the shoulder blades, at its worst from the moment it starts. The pain can move to the neck, belly or legs. Some people faint, become breathless or have stroke symptoms. Call 911 immediately.

What causes aortic dissection?

It happens when the inner layer of the aorta tears, usually in a wall weakened by long-term high blood pressure, aortic enlargement or inherited connective tissue disorders such as Marfan syndrome. Cocaine use, bicuspid aortic valve, pregnancy and heavy lifting can also trigger it in people at risk.

What is the difference between type A and type B aortic dissection?

Type A involves the ascending aorta near the heart and needs emergency surgery because it can rupture into the heart sac or block heart and brain arteries. Type B involves only the descending aorta and is often managed with blood pressure medicines, or a stent graft if complications occur.

What is the survival rate for aortic dissection?

Untreated type A dissection has a very high early death rate, rising each hour. With emergency surgery, most patients survive to hospital discharge. Uncomplicated type B dissection treated with medicines has good short-term survival. Long-term outcomes depend on blood pressure control and follow-up.

Can you live a normal life after aortic dissection?

Many people return to work and normal daily activities. They need lifelong blood pressure control, regular aortic imaging, and to avoid heavy weightlifting, straining and stimulant drugs. Moderate aerobic exercise such as walking is usually encouraged, guided by the care team.