An aortic dissection is a serious condition in which a tear develops in the inner layer of the aorta, the large blood vessel branching off the heart. Blood surges through this tear into the middle layer of the aorta, causing the inner and middle layers to separate (dissect). If the blood-filled channel ruptures through the outside aortic wall, aortic dissection is usually fatal.
Aortic dissection, also called dissecting aneurysm, is relatively uncommon. Anyone can develop the condition, but it most frequently occurs in men between 40 and 70 years of age. The signs and symptoms of aortic dissection may mimic those of other diseases, often leading to delays in diagnosis. However, when an aortic dissection is detected early and treated promptly, your chance of survival greatly improves.
The symptoms of an aortic dissection may be similar to those of other heart problems, such as a heart attack. Typical signs and symptoms include:
- Sudden severe chest or upper back pain, often described as a tearing, ripping or shearing sensation, that radiates down the back
- Loss of consciousness (fainting)
- Shortness of breath
An aortic dissection occurs in a weakened area of the aortic wall. Chronic high blood pressure may stress the aortic tissue, making it more susceptible to tearing. You can also inherit a condition associated with a weakened and enlarged aorta, such as Marfan syndrome. Rarely, aortic dissections may be caused by traumatic injury to the chest area, such as during motor vehicle accidents.
Aortic dissections are divided into two groups depending on which part of the aorta is affected:
- Type A. This is the more common and dangerous type of aortic dissection. It involves a tear in the ascending portion of the aorta just where it exits the heart or a tear extending from the ascending portion down to the descending portion of the aorta, which may extend into the abdomen.
- Type B. This type involves a tear in the descending aorta only, which also may extend into the abdomen.
The strongest risk factor for aortic dissection is uncontrolled high blood pressure (hypertension), which is observed in at least two-thirds of all cases. Other cardiovascular risk factors include:
- Hardening of the arteries (atherosclerosis)
- Weakened and bulging artery (pre-existing aortic aneurysm)
- An aortic valve defect (bicuspid aortic valve)
- Constriction of the aorta (aortic coarctation)
People with certain genetic diseases are more likely to have an aortic dissection than are people in the general population. These include:
- Turner syndrome. People with this syndrome have 45 chromosomes, including one missing or incomplete X chromosome, instead of 46. High blood pressure, heart problems and a number of other health conditions may result from this disorder.
- Marfan syndrome. This is a condition in which connective tissue, which supports various structures in the body, is weak. People with this disorder often have aneurysms of the aorta and other blood vessels. These weak blood vessels are prone to tears (dissection) and rupture easily.
- Ehlers-Danlos syndrome. This group of connective tissue disorders is characterized by skin that bruises or tears easily, loose joints and fragile blood vessels.
Cocaine use has also been implicated as a risk factor for aortic dissection, most likely because the drug temporarily raises blood pressure. Infrequently, aortic dissections occur in otherwise healthy women during pregnancy.
When to seek medical advice
If you have symptoms such as severe chest pain, fainting or sudden onset of shortness of breath, contact your doctor or call for emergency medical assistance. While experiencing such symptoms doesn't necessarily mean that you have a serious problem, it's best to get checked out quickly. Early detection and treatment may help save your life.
An untreated aortic dissection can be fatal. The most common cause of death is rupture of an aortic dissection into one of the body cavities, which causes severe internal bleeding. Sometimes an aortic dissection runs down the length of the aorta and affects the arteries that branch off the aorta. If an aortic dissection interferes with blood flow from these vessels to the rest of the body, tissue damage such as stroke or paralysis may occur.
The most important way to help prevent an aortic dissection is to keep your blood pressure under control. Here are a few tips to reduce your risk:
- Control your blood pressure. If you have high blood pressure, get a home blood pressure measuring device to help you monitor and keep your blood pressure well controlled.
- Don't smoke. Or, if you do, take steps to stop.
- Maintain an ideal weight. Follow a low-salt diet and exercise regularly.
- Watch your cholesterol. Keep your cholesterol levels within a range that is recommended by your doctor.
- Wear a seat belt. This reduces the risk of injury to your chest area.
- Keep your doctor well-informed. If you have a family history of aortic dissection, talk to your doctor.
If you have a genetic condition that increases your risk of aortic dissection, your doctor may recommend medications, even if your blood pressure is normal. Talk to your doctor about which method or combination of methods is best for you.
Based on the Mayo Clinic's Aortic Dissection Guide. Copyright 1998-2009 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved.