Source: Times Online (UK)

Dick Cheney, the US Vice-President who has previously suffered four heart attacks, is undergoing medical treatment after developing deep vein thrombosis (DVT) in his left leg during a 25,000-mile tour of the Asia-Pacific last week.

The blood-clotting condition - nicknamed 'economy class syndrome' because people who fly in cramped conditions are usually most at risk - was diagnosed in the 66-year-old yesterday.

Despite travelling in comfort in an exclusive compartment on Air Force Two, Mr Cheney is still prone to the condition because of his history of blood clotting and heart attacks.

The Vice-President, whose first attack came when he was just 38 years old, last week travelled 25,000 miles and spent 65 hours in the air during a nine-day trip to Japan, Australia, Pakistan, Oman and Afghanistan.

“The Vice-President experienced mild calf discomfort today. In light of his recent prolonged air travel, he visited his doctor’s office,” Megan McGinn, his spokeswoman, said in a statement last night.

“An ultrasound revealed a deep venous thrombosis (DVT) or ’blood clot’ in his left lower leg.

"His doctors will treat him with blood-thinning medication for several months. The Vice-President has returned to the White House to resume his schedule."

DVT can be fatal if not treated quickly enough, with the risk of the blood clot moving to the lungs, potentially causing a pulmonary embolism.

According to Dr Thomas Stuttaford, The Times's medical expert, all those considered prone to developing the condition should take a number of precautions before stepping onto a long-haul flight.

"My advice to any such person who is planning to fly would be to go on anti-coagulation medication before flying, wear special stockings, and walk up and down the plane every 40 minutes," he said.

"In terms of alcohol consumption, he or she should drink only red wine, and limit consumption to two glasses during the flight. That has to be taken hand-in-hand with plenty of non-alcoholic fluids to keep hydration levels up."

Mr Cheney experienced his first heart attack in 1978 when he was only 38 - the same year he was first elected to Congress.

In 1984 he suffered his second attack and - after his third heart attack in 1988 - he underwent quadruple coronary artery bypass surgery before going on to become Secretary of Defence under President Bush Snr during the first Gulf War.

He had his fourth heart attack in 2000, the year he and President George W. Bush won election to the White House, and underwent an angioplasty weeks after being sworn in as Vice-President in 2001.

In September 2005, Mr Cheney had an operation for blood clots behind each of his knees, and then in January 2006 he was hospitalised for shortness of breath.

A lifelong Republican with close relations with the oil and defence industries, the Vice-President has a reputation as an uncompromising hawk in Mr Bush's administration.

Last week the Taleban claimed that a suicide bomber who killed more than 20 people had been attempting to assassinate Mr Cheney while he was in Afghanistan. The explosion, on February 27, eventually killed 23 and wounded 20 more but failed to reach the Vice-President as he visited a US military base in the war-torn country.

The actual cause of DVT has only become firmly known within the medical profession over the last few years, although famous figures in the past have also suffered from it.

Most notably, Richard Nixon was reported to have suffered DVT on the presidential jet whilst 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 from the condition after he returned from Europe.