Andrew Herbert Foster, 42, a physician who had served as chief of service and associate surgery professor in the George Washington University Medical Center's cardiothoracic surgery division since 1998, died of lymphoma July 16 at a hospital in Baltimore. He lived in Severna Park, Md.

Dr. Foster, a New Jersey native, graduated from the University of Michigan, with high honors, in 1978, and from its medical school, with distinction, in 1982.

Dr. Foster interned and served a surgical residency at the university hospital before serving from 1984 to 1986 as a cardiothoracic clinical associate and staff fellow with the National Institutes of Health.

From 1989 to 1991, he served a residency in cardiothoracic surgery at the Medical College of Virginia in Richmond.

From 1991 to 1997, Dr. Foster was an assistant surgery professor at the University of Maryland Medical School in Baltimore. He then served there as an associate professor and director of the school's transmyocardial and laser program.

Dr. Foster was a diplomate of the National Board of Medical Examiners and a fellow of the American College of Surgeons.

He also was a member of the Andrew G. Morrow Society of Cardiovascular Surgeons and the Cardiothoracic Surgery Council of the American Heart Association.

He also was the recipient of awards from such organizations as the University of Michigan and NIH.

In 1975 and 1976, Dr. Foster had been a concert flamenco guitarist with the Jose Greco Spanish Dance Co. During that time, he played in Spain and the United Kingdom.

Survivors include his wife, Margaret, and two sons, all of Severna Park; and his parents and a brother.