NEW YORK -- Leona Helmsley, convicted tax evader and queen of the luxury hotel empire that bears her name, will soon be checking into less opulent lodgings as guest of the federal Bureau of Prisons.

Check-in date? April 15, tax day.

Length of stay? Four years, less time off for good behavior.

With her attorney, Harvard law professor Alan Dershowitz, at her side, Helmsley argued tearfully at her resentencing yesterday that her incarceration would jeopardize the life of her husband, ailing real-estate billionaire Harry, 83. Harry Helmsley, she said, "has nobody in the world that can care and love him the way I do. Nobody. He has no family. All he's got is me."

Her lawyers sought leniency, too, on more pragmatic grounds. Serious jail time, they said, would amount to a death sentence for Leona Helmsley, who is 71 and, they said, in failing health.

She suffers from "severe genetic predisposition to cardiovascular catastrophe," argued attorney Sandor Frankel. "She is a woman of very limited life expectancy. The doctors put it in the range of four to six years."

U.S. District Judge Thomas Griesa didn't buy it. He pronounced her fit for prison, "a picture of a quite vigorous woman. ... She is not bedridden, she is not helpless, she is not hospitalized."

A while later, she was.

Dressed in black, Helmsley left the Manhattan courthouse after the sentencing and promptly collapsed in the arms of U.S. marshals. Later in the day, she was taken by ambulance from her home to New York Hospital, where she was admitted and treated for an "irregular heartbeat," her doctors said.

Dershowitz has made a final motion for a new trial. If it is denied, sources say Helmsley will most likely be sent to the Federal Medical Center, a minimum-security women's prison in Lexington, Ky. There, Helmsley would initially share a dormitory room with at least 10 "little people" -- the sort of individuals Leona once said were the only ones who paid taxes, as her former housekeeper testified at her trial in 1989.

She will be eligible for parole after serving one-third of her sentence.

The Helmsleys avoided paying more than $1.7 million in federal and state taxes from 1983 through 1985 by billing personal expenses to business accounts, a jury found. Leona Helmsley has been free on $25 million bail. She must now repay those taxes in addition to fines of $6.3 million -- an $850,000 reduction from her original sentence.

Much of the pre-sentencing debate yesterday centered around just how robust the Helmsleys are.

"Mr. and Mrs. Helmsley are both shut-ins," attorney Frankel said. "They live only in their homes."

That is "homes," plural -- in Connecticut, New York, Arizona and Sarasota, Fla. -- the judge dryly noted, observing that the Helmsleys are spry enough to continue zipping from penthouse to mansion in the Helmsley-owned 727.

Leona Helmsley recently felt well enough to appear on several talk shows denouncing the government, said Assistant U.S. Attorney Mark Hellerer. And she still conducts business as director or chief of operations for a long string of Helmsley-owned establishments, Hellerer said.

Harry Helmsley was spared a trial for medical reasons. He is so ill, Frankel said yesterday, that when told that his wife may be "removed from his presence ... the electrodes on his body shook so violently that accurate measurements couldn't be taken."

Harry Helmsley was not in court today. But sitting inconspicuously in the packed rows of spectators were several very important "little people," the ones who had sat in a jury box and pronounced his wife guilty three years ago.