Sen. Jesse Helms was awake and responding to his wife and other family members Friday, a day after undergoing an operation to replace a worn-out pig valve installed in his heart 10 years ago.

The 80-year-old senator remained in a hospital cardiac intensive care unit but received visits from wife Dorothy and others in his family, said his chief of staff, Jimmy Broughton. The family "remains optimistic" about the success of the surgery, the aide said.

Broughton said he did not know Helms' condition or how long he would remain in intensive care, and officials at the Inova Fairfax Hospital outside Washington deferred all questions to Helms' office.

On Thursday Broughton issued a statement that "the surgical team led by Dr. Alan Speir is very satisfied with the surgical outcome thus far."

He said he did not know how long Helms would be hospitalized or when he would return to his normal schedule. "He did very well," Broughton said. "All vital signs are stable."

Helms, known for his strong conservative views on social issues and his opposition to communist regimes, has announced he will retire in January after 30 years in the Senate. He has had several health problems in recent years, including knee-replacement surgery and prostate cancer, and often travels around the Capitol in a motorized scooter.

A new pig valve was substituted for one that was used to replace Helms' mitral valve in 1992. The mitral valve guards the opening between the left upper and lower chambers of the heart. It is not unusual for pig valves to wear out and need replacement after a period of years.

The other repair work was done to the tricuspid valve between the right auricle and ventricle of the heart, which prevents blood from flowing back into the auricle.