Joan R. Braden, 77, a leading Washington personality and a friend and confidante of political leaders and high federal officials for more than three decades, died yesterday. She collapsed at Sutton Place Gourmet in Alexandria after a heart attack and was pronounced dead at Inova Alexandria Hospital.

Like others before her in this city, she had served in political campaigns and worked in government and journalism. She went on to become a close aide and confidante to some of Washington's most powerful men and to spend decades as a hostess to Washington's best and brightest. She did this while raising eight children, a saga captured by her husband, columnist Tom Braden, in the book "Eight Is Enough," and in an ABC television series of the same name.

Mrs. Braden was a former State Department officer, public relations executive, magazine writer, television interviewer, political campaign worker for John F. Kennedy and Robert F. Kennedy, and an economic aide and personal secretary to Nelson Rockefeller.

She was a frequent companion and a partner on trips with former defense secretary and World Bank president Robert S. McNamara, with whom she had what Washington Post staff writer Paul Hendrickson described as a "romantic relationship conducted more or less openly."

In 1960, she was one of the California managers of the Kennedy for President campaign, and she arranged to fill the Los Angeles Coliseum one night for a Kennedy political rally. She accompanied first lady Jacqueline Kennedy to India in 1962 and then wrote about the trip for the Saturday Evening Post. In 1968, she was with Robert F. Kennedy at the Ambassador Hotel in Los Angeles when the New York senator was assassinated after winning California's Democratic presidential primary.

For years, her home in Chevy Chase was the setting for low-key, off-the-record dinner parties where officials could speak their minds without having to worry that they would read about it in the morning newspapers. In a 1976 profile, Washington Post staff writer Sally Quinn wrote: "At the Bradens', there are the kids or the occasional Cambodian waiting casually on the table. The wine is warm and cheap. It is agreed that she may set the worst table in Washington, but no one seems to mind. It's not the food after all, it's the people. She's brought a new dimension to entertaining in Washington."

Henry Kissinger used to spend Christmas Eve at the Bradens' home, which he told friends was one of the few places in town where he could relax with people who made no demands on him. AFL-CIO chief Lane Kirkland came by on Thanksgiving. "It's very important that someone can come to dinner without having it known. When I have friends for dinner, it's because I like them. You can't keep friendships otherwise," Mrs. Braden once said.

Joan Ridley Braden was born in Indianapolis, and she grew up in Anderson, Ind., and later in Washington, where she graduated from Wilson High School. She attended Hollins College and the University of California at Los Angeles and graduated from Northwestern University.

She was a civilian intelligence officer at the Pentagon during World War II. She later moved to New York, where she was a personal secretary and economic assistant to Rockefeller. Tom Braden also was working for Rockefeller in those years, and in 1948 they were married.

In 1951, he took a job with the Central Intelligence Agency and they relocated to Washington, where she became a special assistant to Oveta Culp Hobby at the Department of Health, Education and Welfare. Later they moved to Oceanside, Calif., where he had purchased the Blade-Tribune newspaper with a $185,000 loan from Rockefeller. Mrs. Braden wrote articles for the paper and later worked in the political campaigns of John and Robert Kennedy.

After 14 years in California, the Bradens came back to Washington, where she did television interviewing for WTOP-TV and fund-raising for the American Film Institute and traveled around the world overseeing development projects for the Community Development program.

She also built an extensive network of social and political contacts, primarily on the basis of what was said to be an extraordinary charm, warmth, charisma and an ability to make people feel good about themselves. And she raised eight children, which became the basis of a book by her husband, "Eight Is Enough," which in turn became the basis of a television series that ran on ABC from 1977 to 1981. In that book, Braden wrote of his wife: "She's blithe. That's what it is about her, and that is why she is so everlastingly cheerful. What she needs is somebody to shake her by the shoulders and tell her that life is real and life is earnest, and to quit smiling about it so much."

In 1976, she was appointed consumer affairs coordinator for the State Department, stirring speculation in the media that she got her job because of her friendship with former secretary of state Henry Kissinger, which both Mrs. Braden and the secretary denied.

In addition to her husband, survivors include seven children, David Braden of Taiwan, Mary Poole of Alexandria, Joan Ridder of Denver, Susan Zarker of Takoma Park, Nancy Braden of Denver, Elizabeth Braden of Denver and Nicholas Braden of Alexandria; and 12 grandchildren. A son, Tom Braden, died in 1994.

CAPTION: Joan Ridley Braden was 77.