WASHINGTON, Jan. 9 - Vice President Dick Cheney went to a hospital for four and a half hours early Monday morning after complaining of shortness of breath, but he was back at the White House in the afternoon, amid a number of unanswered questions about his condition.
The White House said the 3 a.m. trip to George Washington University Hospital was necessary because of fluid retention as a side effect of a drug Mr. Cheney, 64, had taken to treat chronic foot ailments. Last week, Mr. Cheney was seen using a cane, and the White House said he had a "pre-existing condition" in his foot, but the problem was not described with precision.
President Bush, asked about the vice president, said: "He's doing fine. I talked to him this morning. His health is good." But as is often the case with Mr. Cheney, one of the nation's most famous heart patients, details about what led to his health problem and the exact treatment he received were scanty.
Mr. Cheney's office said he had been using an anti-inflammatory drug that caused a buildup of fluid in his lungs, leading to shortness of breath. He began taking a diuretic to remove the fluid, his office said. His office said Monday that Mr. Cheney had long suffered periodic pain in his heel, which has been diagnosed as tendonitis, and in his big toe, which has led to a murkier diagnosis: gout or osteoarthritis.
The White House declined to identify the drug that doctors had prescribed to treat the symptoms. Fluid retention is a known complication of nonsteroid anti-inflammatory drugs, and Mr. Cheney faced additional risks because of his chronic coronary heart disease. Heart patients can gain several pounds in a few days while taking the drugs, said Dr. Steven B. Abramson, who directs rheumatology at New York University.
Several heart attacks have reduced the ability of the left ventricle to pump blood to Mr. Cheney's body. The left ventricle is the heart's main pumping chamber, and his doctors have estimated that his ejection fraction, a main measure of heart function, is about 40 percent. Normal is 55 percent to 70 percent.
Mr. Cheney has been taking a long list of medications for a number of conditions, including heart disease and gout. His doctors have said he takes a standard regimen for impaired heart function, though they have not named the drugs.
Doctors not involved in Mr. Cheney's care have described his condition as mild to moderate left ventricular malfunction and compensated heart failure.
On Monday, Dr. Christopher P. Cannon, a cardiologist at Harvard Medical School, said the fluid retention possibly indicated Mr. Cheney's heart was decompensating and "teetering on the edge of congestive heart failure." The fluid retention does not necessarily indicate a worsening of his heart condition.
"Time will tell whether this would happen in the absence of this event or whether he could stay in compensated heart failure, as he has been," Dr. Cannon said in an interview. He also said it was unlikely that "a healthy person would get short of breath" from taking a nonsteroid anti-inflammatory.
Speaking of heart patients in general and not of Mr. Cheney's case, Dr. Robert O. Bonow, chief of cardiology at Northwestern University in Chicago, said doctors and patients were cautioned not to use a nonsteroid anti-inflammatory without considering a risk of fluid retention.
When patients like Mr. Cheney develop complications from the drugs, doctors often have to prescribe painkillers as an alternative. They usually start with nonnarcotic painkillers but may have to move to stronger drugs if necessary.