Vice President Dick Cheney arrived for work at the White House Monday afternoon after resting at his residence following an overnight visit to George Washington Hospital for shortness of breath.

Cheney has a long history of heart problems and has a pacemaker but it appears that his complications are related to an anti-inflammatory medication he was taking for a foot problem.

Cheney was seen Friday using a cane. He told workers at the Harley-Davidson factory he was touring in Kansas City, Mo., that he needed the assistance because "(Defense Secretary) Don Rumsfeld has been chewing on my ankles."

The vice president was taken to the hospital in a government car after complaining about difficulty breathing, said Lea Anne McBride, a spokeswoman for Cheney.

An electrocardiogram was performed on him and doctors determined it was unchanged. Doctors eventually determined he was retaining fluid because of the medication. Cheney was placed on a diuretic and was released around 7:30 a.m. EST, about four-and-a-half hours after being admitted.

President Bush's doctor told him about Cheney's visit to the hospital early Monday before Bush went to the Oval Office, White House spokesman Scott McClellan said.

"He's doing fine," Bush told reporters during a visit to a Maryland elementary school. "I talked to him this morning. His health is good. He'll be coming in to work a little later on today."

Bush spoke with Cheney by phone after he returned to his residence, McClellan said.

"The vice president indicated to the president that he was doing fine, and the president was glad to hear that," McClellan said.

McClellan said Bush was "absolutely" not considering replacing the vice president.

"The vice president's doing a great job on behalf of the American people," he said. "He's a very important member of the team."

McBride said the foot condition was not related to surgery last September to repair aneurysms behind both knees or the 64-year-old vice president's lengthy history of heart problems. She said he has occasional bouts with inflammation in the heel, which has been diagnosed as tendonitis, and sometimes in the joint of the big toe of his left foot, which some doctors suggest might be gout or osteoarthritis.

McBride said Cheney does not suffer from the acute pain usually associated with gout nor does he have raised levels of uric acid in his blood, which is also associated with condition.

Cheney's medical history includes four heart attacks, quadruple bypass surgery, two artery-clearing angioplasties and an operation to implant a special pacemaker in his chest.

It was unclear exactly what medication Cheney was taking for his foot ailment, but a side effect of commonly used anti-inflammatory drugs is fluid retention, which can cause swelling and shortness of breath and strain the heart muscle.

Fluid can also leave the circulatory system and accumulate in various parts of the body, including the lungs, which can cause a shortness of breath.

All anti-inflammatory drugs — popularly known as NSAIDs, non-steroidal anti-inflammatories, including such drugs as ibuprofen and naprosyn — can cause that side effect. Now that Cheney has suffered it, he should avoid those medications, said Dr. Stuart Seides, associate cardiology director at Washington Hospital Center.

"It's not common, but it's certainly not rare," he said of the side effect. "Non-steroidals, many of which are over-the-counter, are not entirely benign drugs. The fact that they are sold over-the-counter does not mean that they don't have potent physiologic effects."

But once the side effect is treated, Cheney should have suffer no lasting harm from the episode, Seides said.

"It should have no effect on him or his long-term prognosis," he said.

The condition is usually treated with a diuretic.

Cheney has a long history of health problems and suffered his first heart attack in 1978 when he was 37. Ten years later, after his third heart attack, he had quadruple bypass surgery to clear clogged arteries.

Cheney, who has not suffered a heart attack since he became vice president in 2001, began a daily exercise program in 2000 and started eating healthier.

He quit smoking in 1978 and takes medication to lower his cholesterol.

FOX News' Greg Kelly and The Associated Press contributed to this report.