New York Times

WASHINGTON — Justice Ruth Bader Ginsburgunderwent a heart procedure on Wednesday morning and was expected to leave the hospital within the next two days, the Supreme Court announced.

Justice Ginsburg, 81, “experienced discomfort during routine exercise” on Tuesday night and was taken to MedStar Washington Hospital Center, the court said in a statement. Doctors placed a stent in her right coronary artery, a procedure known as a coronary catheterization.

“She is resting comfortably,” the statement said.

Kathleen Arberg, the court’s public information officer, added that “Justice Ginsburg expects to be on the bench on Monday.” The court is scheduled to hear two arguments that day, including one on how the First Amendment applies to threats conveyed on Facebook.

Justice Ginsburg is the senior member of the court’s four-person liberal wing, a role she seems to enjoy. She has resisted calls for her resignation from liberals who say they want President Obama to name her replacement, rather than a possible Republican successor.

The issue is now largely moot. The Republican takeover of the Senate next month will almost certainly narrow the range of candidates who could be confirmed in the last two years of Mr. Obama’s presidency.

Justice Ginsburg has repeatedly vowed in recent months to stay on the court as long as her health holds and she stays mentally sharp. Inan interview last year, she said she loved her work and intended to continue “as long as I can do the job full-steam, and that, at my age, is not predictable.”

She has had cancer twice, and has attributed her survival partly to the medical care she received at the National Institutes of Health.

“Ever since my colorectal cancer in 1999, I have been followed by the N.I.H.,” she said in the interview. “That was very lucky for me because they detected my pancreatic cancer at a very early stage” in 2009.

Justice Ginsburg was back on the bench less than three weeks after undergoing the second cancer surgery.

“After the pancreatic cancer, at first I went to N.I.H. every three months, then every four months, then every six months,” she said. “The last time I was there they said, ‘Come back in a year.’ ”

She said in the interview last year that she was working out twice a week with a trainer, and in remarks at a bar association in February, she said the trainer “has been my physical fitness guardian since 1999.”

The court’s prompt and detailed announcement of Wednesday’s heart procedure was characteristic of Justice Ginsburg’s openness about her health and other matters. Last month, she had the court issue a statement announcing that she was correcting a factual error in a recently issued opinion.

Justice Ginsburg was named to the court in 1993 by President Clinton. She was the first Democratic appointment since 1967, when President Lyndon B. Johnson nominated Thurgood Marshall.

Mr. Clinton appointed Justice Stephen G. Breyer, now 76, in 1994.

Five of the justices were appointed by Republican presidents and four by Democrats, and their partisan affiliations often predict their votes in ideologically charged cases.

Justice Ginsburg was born in Brooklyn in 1933, graduated from Cornell in 1954 and began law school at Harvard. After moving to New York with her husband, she transferred to Columbia, where she earned her law degree.

She taught at Columbia and Rutgers and was a leading courtroom advocate of women’s rights before joining the court. As director of the Women’s Rights Project of the American Civil Liberties Union in the 1970s, she brought a series of cases before the court that helped establish constitutional protections against sex discrimination.

Her litigation strategy invited comparison to that of Justice Marshall, who was the architect of the civil rights movement’s incremental legal attack on racial discrimination before he joined the court.

Justice Ginsburg previously served for 13 years as a judge on the United States Court of Appeals for the District of Columbia Circuit.

She is now the oldest member of the Supreme Court and has shown no signs of slowing down. She stayed up all night last month to put the finishing touches on a dissent from an order allowing Texas to use its strict voter ID law. The opinion was issued shortly after 5 a.m.

In the interview last year, she said her age has required only minor adjustments.

“I don’t water-ski anymore,” Justice Ginsburg said. “I haven’t gone horseback riding in four years. I haven’t ruled that out entirely. But water-skiing, those days are over.”