(See Corrections & Amplifications item below⁰.)

REDDING, CALIF. -- Chae Hyun Moon, director of cardiology at Redding Medical Center, arrived in this Northern California town for the first time more than 20 years ago, driving a 1975 Oldsmobile and blaring the Beach Boys over his radio. "It reminded me of home back in Korea," he recalls. "People were friendly."

Dr. Moon says he was disenchanted with the practice of medicine in the Orange County region of Southern California and was looking for a place to relocate "without all the politics." Redding was a small, growing town that needed doctors, so Dr. Moon and his fiancée, soon to be his wife, decided to make their home there. "It has been a wonderful life until now," says Dr. Moon.

A week ago Wednesday, while he was in the middle of performing a cardiac procedure at the hospital, Federal Bureau of Investigation agents appeared at the door, flashing badges and demanding immediate entry. During the same procedure, the phone in the catheterization laboratory rang with an urgent call for Dr. Moon: Agents had shown up there, too.

The FBI agents swept through the hospital, Dr. Moon's office, and the offices of cardiac surgeon Fidel Realyvasquez, who also practices at the hospital. They were collecting medical records and other evidence for an investigation into allegations made by at least one patient, as well as other doctors, that during the years the men have performed hundreds of unnecessary surgeries and other invasive procedures at the hospital, which is owned by Tenet Healthcare Corp.

No charges have been filed in the case, but the allegations, disclosed in a publicly released affidavit, and the raid have caused the stock price of the nation's second-largest hospital company to plunge. The raid came at a sensitive time for Tenet, which was already under scrutiny for the high level of so-called "outlier" payments it receives from Medicare.

"People are questioning the meaning of my life over the past 23 years," Dr. Moon said Wednesday in an emotional interview in his attorney's office.

Then, Dr. Moon and his wife broke down in quiet sobs, unable to talk further. In a statement, the attorney, John Reese, said his client denies all of the accusations against him.

The sheer volume of procedures performed by Dr. Moon and Dr. Realyvasquez was cited by the government as the basis for the raids last week. The 238-bed hospital reported performing 923 open-heart surgeries and more than 16,000 catheterizations in the 12 months ended May 31, 2001, according to the latest annual disclosure report filed with California's Office of Statewide Health Planning and Development.

Dr. Moon says the statistics are misleading because 40% of the program's patients come from outside the Redding area, drawn by the reputation of the hospital's heart-care program.

At the hospital, co-workers have rushed to the doctors' defense. After a candelight rally held last Friday night, a huge banner was hung in a hospital corridor that read, "We Support Our Doctors." It was signed by scores of staff members.

Staffers say that Dr. Moon works hard for his patients, fielding frequent, repeated phone calls in the middle of the night. But they also concede that his brusque bedside manner can be alienating. "He has this very cut and dried approach," and after he has rendered his professional opinion he indicates that "you can take it or leave it," says Tamara Caudle, director of cardiology and vascular services at Redding.

Dr. Moon attributes his manner to his Korean background. In East Asia, doctors are rarely questioned by their patients and the concept of "informed consent," where patients get a thorough explanation of why a certain treatment is being recommended, has never gained traction. In explaining his approach, Dr. Moon cites an old Korean proverb, "Empty cars make more noise," adding that he wants to be judged on what he does and not what he says.

Dr. Moon, now 55 years old, came to the U.S. in 1947 after attending Yonhap Medical School in Seoul. He is the oldest of six brothers, with a father who was a physician and a mother who headed an organization that worked for women's rights. After doing an internship and residency in New York, he spent two years studying cardiology at the Cleveland Clinic before heading to California.

In Redding, his practice grew quickly. But patients who needed cardiac surgery had to be flown or driven by ambulance 160 miles south to Sacramento. Dr. Moon worked with the hospital to try to bring a surgery program to town, but there was skepticism in the medical community about whether there would be enough patients to make the program viable.

Eventually, four surgeons from Mercy General Hospital in Sacramento began a regular rotation, allowing the heart-surgery program to get rolling. One of the surgeons, Dr. Realyvasquez, liked the community so much that he decided to move permanently, says Sheryl R. Hallstrom, a longtime nurse at the hospital.

Dr. Realyvasquez couldn't be reached. His attorney says he left Saturday on a vacation that had been scheduled before the government raid. Dr. Moon is still seeing patients. He is one of the busiest of about 10 cardiologists at the hospital, and Dr. Realyvasquez is one of two cardiothoracic surgeons there.

Ironically, Dr. Moon has been slowing down from the peak pace he set several years ago. Hospital administrators said they have been searching for a cardiologist to succeed Dr. Moon, who told them a year ago he wanted to retire. Now, he says, "I have to stay to clear my name."

Corrections & Amplifications:

Redding Medical Center's chief of cardiology, Chae Hyun Moon, was born in 1947. This article incorrectly said Dr. Moon arrived in the U.S. in 1947.

Write to Rhonda Rundle at rhonda.rundle@wsj.com⁴

Updated November 7, 2002 11:24 p.m. EST