What constitutes an aortic dissection? An aortic dissection is a tear in the inner layer of the aortic wall. This allows blood to enter and separate the inner and outer layers of the vessel. Dissection can weaken the outer wall, resulting in rupture or formation of an aneurysm, occlusion of aortic branch vessels, and disruption of the aortic valve.

What are the symptoms of an aortic dissection? The primary symptom of an aortic dissection is severe pain usually in the chest (front, back or both), but occasionally in the abdomen when the tear begins in that part of the aorta. However, dissections can also cause a variety of other symptoms: pain, pallor, pulselessness, parathesia and paralysis (the 5 P's). If a branch of the aorta is blocked, weakness in one or both legs or arms may be evident.

For a person with the Marfan syndrome or another aortic disease, there are no consistent, standard symptoms of an aortic dissection. However, any type of pain in the chest, back or abdomen that is along the midline of the body - in front, back or both - that is either especially severe or sharp and has a burning or tearing quality, or is relatively severe and totally different that has ever been felt before, has the possibility of being an aortic dissection and should be evaluated promptly.

Why is emergency diagnosis and treatment of aortic dissection an important issue? Although aortic dissection is uncommon, it is not rare. However, when it is does occur, it is commonly catastrophic. An aortic dissection that doesn't stop tearing will ultimately become a fatal rupture. Based on available medical information, there are probably 5,000-10,000 dissections a year in the United States.

Community marketplace Unless someone has a known diagnosis of the Marfan syndrome or very obvious physical characteristics that would indicate the Marfan syndrome or another predisposing condition, aortic dissection would rarely be the first diagnostic consideration for an emergency patient with chest pain.

Which populations at high risk for an aortic dissection are emergency personnel most likely to encounter? People with the Marfan syndrome are among those at high risk for aortic dissection. In addition, other people who have known or unknown enlargement of the aorta, so-called known pulsatile abdominal masses, "Triple A's" - Abdominal Aortic Aneurism bicuspid aortic valves, high blood pressure, or have family history of aortic dissections are also at substantially increased risk for aortic dissections, as are women with Turner syndrome. These groups merit closer attention in an emergency setting.

Aortic dissection is the primary cause of death in individuals with the Marfan syndrome.

Emergency personnel should be aware of the classic features of the Marfan syndrome:
Disproportionately long arms, legs, fingers and toes.
Pigeon breast in which the breast bone protrudes forward.
Funnel chest in which the breast bone is prominently caved inward.
A very marked curvature of the spine.
Presence of lens dislocation may also be a telltale sign of the Marfan syndrome.

When should an aortic dissection be considered as the diagnosis? It is important to recognize signs of aortic dissection. It is the leading cause of mortality in people with the Marfan syndrome. If someone doesn't have a diagnosis of the Marfan syndrome or any other predisposing condition for aortic disease, the symptom of severe unprecedented pain in the midline of the chest or abdomen should at least raise the possibility of a dissection. The location of the pain indicates the portion of the aorta involved in the dissection. Pain that penetrates from front to back (midscapular) at the outset, and changes location over time, may also indicate an ascending dissection. The changing location of the pain is an indication that the dissection is progressing.

Rather than think that every chest or abdominal pain is a dissection, the key is to remember certain characteristics that make dissection a more likely possibility, and ensure that aortic dissection is considered as a possible diagnosis.

What information should the emergency team obtain from a patient with chest pain? Upon arrival of emergency personnel, the patient should be asked to clearly describe the pain its location and severity, and the extent to which it is different from previous pain. While gathering the medical history, the patient should be asked about any known diagnosis of the Marfan syndrome or other form of aortic disease.

What part of the physical exam raises the possibility of an aortic dissection? During the physical examination, it is important to check the blood pressure in both arms and the pulses in both wrists, both legs and both sides of the neck over the carotid arteries. If an aortic dissection is present, a difference in blood pressure can sometimes be found between the arms and the differences in the pulse can be detected.

Many people with the Marfan syndrome are treated with medications to keep their blood pressure at the very bottom of the normal range. It is important to ask patients with a known diagnosis of the Marfan syndrome their normal blood pressure so that, if the emergency providers detect a blood pressure of, for example, 100/60, they are aware that it is the patient's usual blood pressure and not the result of an acute event.

What are other possible causes of chest pain? There are many other causes for the type of chest pain associated with an aortic dissection. These include a heart attack (myocardial infarction) and inflammation of the lining around the heart (pericarditis). Problems with the esophagus and the spine also could cause pain in the same general area, although they tend to have different symptoms.