VP's Blood Clot Focuses Attention on Common Condition

< Mar. 07, 2007 > -- Vice President Dick Cheney's diagnosis of a blood clot in his leg has focused needed attention on this common and potentially life-threatening problem, heart experts say.

Deep vein thrombosis (DVT) is caused by a clot in a larger vein, typically in the leg. The clot can break off and travel through the bloodstream before lodging in the lungs, brain, heart, or other organ, causing severe damage or death.

According to the Federal Aviation Administration (FAA), DVT has been erroneously called "economy class syndrome" because of the perception that passengers in the more restrictive coach or economy class of aircraft are more likely to develop DVT.

Recent research, however, has found that airline passengers in any seating class may develop DVT, states the FAA. But DVT is a risk for anyone who has endured prolonged sitting or bed rest.

Other risk factors include heart disease; recent surgery or trauma (especially hip, knee, or gynecological surgery); fractures; childbirth within the last six months; and use of medications such as estrogen, according to the US National Institutes of Health (NIH).

Small Problem May Become Life Threatening

"DVT ranges from a minimal inconvenience to something that is potentially life-threatening," says Dr. Stephen Siegel, a cardiologist at New York University Medical Center and a clinical assistant professor at NYU School of Medicine.

A typical symptom of DVT is a continuous pain in the calf, Dr. Siegel says. "It is frequently associated with some redness or point tenderness, a streak over the vein can sometimes be seen, and sometimes the leg becomes swollen," he says.

In severe cases, a patient can have difficulty breathing, chest pain, or cough up blood, Dr. Siegel adds.

Cheney's Case Typical

Cheney's condition, which was made public earlier this week, may have been brought on by his recent 25,000-mile trip to Asia, despite the comfort of Air Force Two.

According to the National Aeronautics and Space Administration's (NASA) Occupational Health department, there is increasing evidence that immobilization in airline seats for long flights puts people at risk for DVT.

The vice president, who returned last week from an overseas trip that included stops in Afghanistan and Pakistan, has had a long history of heart ailments. He had four heart attacks before he assumed office in 2001. He has an implanted defibrillator (ICD) to regulate his heartbeat if necessary. And, in 2005, he underwent six hours of surgery on both legs to repair an aneurysm, a ballooning weak spot in an artery that can burst if left untreated.

"The severity of the problem depends on how early it is diagnosed and how early one gets treatment and how far it has progressed," Dr. Siegel says.

DVT is typically treated with blood thinners, as was done in Cheney's case. "Blood thinners keep the clot from growing and allow time for the body to heal itself," Dr. Siegel says.

No One is Immune

If any symptoms of DVT develop, Dr. Siegel's advice is to see a doctor for a simple imaging test that can easily diagnose the condition. Such imaging tests may include an ultrasound of the leg or a venogram, in which x-rays and intravenous (IV) contrast dye are used to examine blood flow in the legs.

DVT can strike anyone, Dr. Siegel says. "Women may be more prone to it because of hormone replacement therapy," he remarks.

In April 2003, NBC News correspondent David Bloom died suddenly of DVT while covering the war in Iraq. He had been traveling in a military vehicle that had an interior designed for safety, not comfort, and had reportedly complained of pains in his legs, a classic warning sign for a blood clot.

Former President Richard Nixon was also reported to have suffered DVT on a 1972 flight to the Soviet Union after visiting China, which was given as the reason for his inability to give evidence at the Watergate inquiry. Dan Quayle, a former vice-president, was also reported to have suffered DVT in 1994. He developed a leg clot that traveled to his lung soon after a series of airplane trips. A blood clot that develops in the lung in this manner is called a pulmonary embolism.

Always consult your physician for more information.

What is deep vein thrombosis?

Deep vein thrombosis (DVT) occurs when a blood clot (thrombus) develops in a vein deep in the body. Deep veins are found within groups of muscles. The veins close to the skin are called superficial veins.

DVT may also be referred to as a venous thromboembolism, or VTE.

While these clots most often develop in the lower legs or thighs, they may appear in the upper body, such as the arms or other locations in the body.

Any major surgery carries a risk of DVT, but patients who have surgery of the legs or hips are at higher risk because of reduced mobility.

Pieces of a clot can break off and travel through the bloodstream to the lungs. When this occurs, it is called a pulmonary embolism, which can be fatal.

Deep vein thrombosis can also block blood flow in the veins, causing the blood to pool. This pooled blood can cause swelling, pain, and permanent damage to the leg called post-thrombolic syndrome.

Risk factors related to, or that may contribute to, deep vein thrombosis and thrombophlebitis include, but are not limited to, the following:

• obesity

• an inherited tendency that increases risk for blood clots

• age (greater than 60)

• type A blood group

Deep vein thrombosis occurs without symptoms about 50 percent of the time. When symptoms do occur, they may include:

• swelling in the leg

• red, discolored, or white skin

• a cord in a leg vein that can be felt

• rapid heart beat (tachycardia)

• slight fever

• warm skin

• more visible surface veins

• dull ache, tightness, tenderness or pain in the leg (these symptoms may only occur while walking or standing)

The symptoms of deep vein thrombosis may resemble other medical conditions or problems. Always consult your physician for a diagnosis.