Aorta Disorder Is Rare, Deadly

The aortic dissection that killed actor John Ritter on Thursday -- and that also killed actress Lucille Ball and volleyball player Flo Hyman -- is a rare but deadly disease that generally strikes without warning and kills quickly.

“This is one of the most lethal diseases if it is not immediately detected and treated,” said Dr. P.K. Shah, a cardiologist at Cedars-Sinai Medical Center.

Aortic dissection strikes about 4,000 people per year in the United States, two-thirds of them male, and only a lucky few survive.

The disorder is a catastrophic failure of the aorta, the artery that carries blood from the heart to the brain and other organs of the body. It starts out slowly when the inner lining of the aorta -- one of three layers of the blood vessel -- tears, allowing blood to seep between the layers and create a new channel.

But this new channel has only two layers of tissue holding blood in, rather than the normal three, and is thus much weaker. A sudden spike in blood pressure or a blow to the chest, such as in a car accident, can cause the weakened artery to rupture. The victim feels a crushing or tearing pain in the chest or back.

If it is a large tear, the victim will most likely bleed to death before help can be obtained.

If the tear is smaller and is detected rapidly, surgery must be performed to repair or replace the weakened segment. Ball, for example, had surgery that initially appeared to be successful, but within a week, she suffered another tear that could not be repaired.

Overall, the mortality rate is between 50% and 70%, said Dr. Barry Katzen, founder of the Miami Cardiac & Vascular Institute in Florida.

The symptoms, unfortunately, are the same as those of a heart attack, and some of the treatments for a heart attack, such as blood thinners and clot-busting drugs, are dangerous because they simply increase bleeding.

Blood tests that indicate a heart attack are generally negative and, in rare cases, some victims have actually been sent home, only to die there.

The first tip-offs, Shah said, are differing blood pressures in the two arms or the lack of a pulse in one arm. An X-ray might also reveal an enlargement of the aorta. The problem can be quickly diagnosed with a CT scan or an MRI.

Doctors don’t know a lot about the causes of aortic dissection, although many think that it is genetic in origin. It is associated with some genetic diseases, such as Marfan syndrome (the cause of Hyman’s attack), lupus and giant-cell arthritis, all of which are diseases of the connective tissue.

It also occurs in some people who have a congenitally bicuspid aortic valve, which has two leaflets in the valve rather than three.

People with such conditions can be monitored for the problem. Regular X-rays, for example, can indicate whether the aorta is getting larger, a sign of the problem. In such cases, surgical repairs can be attempted.

Aortic dissection has also been observed in weightlifters and people on cocaine binges.

By far, the most common cause is high blood pressure. For those patients, Katzen said, “there is no advanced warning and no testing that can predict this. It’s not really preventable other than just making sure that blood pressure is under good control.”