Woolworth heiress Barbara Hutton, a former jet setter who became an ailing recluse after her seventh marriage failed, died of a hearth attack Friday in her penthouse suite at the Beverly Wilshire Hotel in Beverly Hills, Calif. She was 66.

She was pronounced dead on arrival at Cedars-Sinai Hospital where she had been discharged just two weeks earlier after treatment for pneumonia.

Plagued by serious illnesses over the years, Miss Hutton reportedly was nearly blind and suffering from a bad hip, injured some years ago in a fall.

She had been separated since 1966 from her seventh husband, Prince Raymond Doan Vinh Na Champacak, an artist of Vietnamese and French extraction, after two years of marriage.

Four of her earlier marriages also had been to titled men - Prince Alexis Mivani of Russian Georgia, Danish Count Kurt Haugwitz-Reventlow, who was the father of her only, child Lithuanian Prince Igor Troubetzkoy and German Baron Gottfried Von Cramm.

In between, Miss Hutton sandwiched in a three-year marriage to wealthy Hollywood film star Cary Grant, who unlike most of her other husbands never asked for or received a penny from her after they parted, and a three-month marriage to notorious playboy Porfirio Rubirosa.

Of her marriage, Miss Hutton once said that Grant was the "the husband I loved most."

She also once said: "Money alone can't bring you happiness, but money alone has not brought me unhappiness. I won't say my husbands thought only of money, but it has a certain fascination for some of them."

Miss Hutton was born to money in New York City, the daughter of Franklyn Laws Hutton and the former Edna Woolworth, whose father founded the Woolworth chain.

She was only five years old when her mother died, and she divided her childhood years living with various wealthy relatives and at a number of elite schools.

At the age of 18, Miss Hutton was introduced to society with a $80,000 debut, which raised eyebrows by its extravagance. It was 1930, the year ofter the Wall Street crash.

A year later, she was presented at the Court of St. James', in London. In the meantime, she met Prince Mdivani. Her father sent her on a trip around the world to discourage the romance, but the prince followed her to Bangkok and they were married in Paris when she was 20 years old.

A few months after the marriage, Miss Hutton turned 21 and inherited more than $20 million, which was doubled for her by investments over the ensuing years.

Her fortune enabled her to continue traveling to exotic placed and she acquired a number of luxurious homes around the world. She changed abodes even more rapidly than husbands.

She and her first prince were idvorced in Reno, Nev., in 1935. She is supposed to have settled $2 million on him while he was still her husband. He died in a car accident shortly aftet the divorce.

Within 24 hours after the divorce was granted, Miss Hutton took a new husband, Count Haugwitz-Reventlow, a wealthy Danish nobleman. That marriage lasted six years and reportedly cost her $1,500,000.

Their son, Lance, was born in London in 1936. It was after his birth that she first became seriously ill. Heavil y guarded during the childhood because of fears of kidnaping, Lance grew up to inherit a fortune from his mother when he reached 21. He also bacame a daredevil race car driver.

Tragedy struck in 1972, when Lance, at the age of 37, was killed in the crash of a light plane near Aspen, Colo.

Miss Hutton wed Grant as her third husband in 1942. She was granted a divorce in 1945 on grounds of mental cruelty. He was more interested in his acting career than in her, she said. She also said that she would not remarry because "you can't go on being a fool forever."

But in 1947, she again took voows with Prince Troubotzkoy. Ill health plagued her during the marriage, and she underwent major surgery for a kidney ailment and an intestinal disorder. She obtained a Paris divorce in 1951.

The marriage to Rubirosa came in December 1953, at a time when actress Zsa Zsa Gabor was proclaiming to all that he really would have liked to jilt Miss Hutton to marry her.

Miss Hutton took that slap with a smile, but the marriage broke up in three months. Rubirosa acquired, among other things, a string of polo ponies and a big plane in that time.

Her sixth marriage was to Baron Von Cramm, an international tennis star, in 1955. They were quietly divorced by "mutual agreement" five years later.

In 1969, Miss Hutton underwent cataract surgery, which left her with impaired vision. Two years later, she tripped on a carpet in Rome and broke her hip. She delayed seeking treatment and complications resulted.

Miss Hutton has been chubby as a young girl and her strenuous dieting in later years was believed partly responsible for her frail health.

She had lived in seclusion in an apartment at the Beverly Wilshire Hotel for a number of years.

An attendant at the mortuary where her body was taken said a lawyer had called there to say the body would be flown to New York on Monday.