Dr. Herrman L. Blumgart '17, professor of Medicine Emeritus and a noted cardiologist, died of a heart attack yesterday morning in Stillman Infirmary at age 81.

One of his former colleagues yesterday described Blumgart as "an institution" in the Medical Area. Bumgart graduated from the Medical School in 1921 and served as head of the school's department of medicine at Beth Israel Hospital, a teaching affiliate, from 1928 to 1962.

"He had an enormous influence on many people," the colleague, Dr. A. Stone Freedberg '29, professor of Medicine Emeritus, said of Blumgart's teaching and research.

In 1924 Blumgart was the first to inject a radioactive substance into patients for treatment, Freedberg said. Blumgart used a derivative of radium to calculate blood flow rates.

The Cambridge resident also performed pioneering research relating thyroid gland function and heart failure.

When Blumgart retired in 1962, he received an honorary Doctor of Science degree from Harvard, and friends and colleagues established an endowed chair in Medicine in his name.

After retirement, the cardiologist served as a consultant to the Medical School dean and as a member of the school's admissions committee.

He was also a practicing physician at the Medical Area Health Service until 1973.

Blumgart was editor-in-chief of the journal of the American Heart Association from 1955 to 1965. He had also presided over the New England Cardiovascular Society and the Harvard Medical School Alumni Association. He received the Gold Heart Award from the American Heart Association for his advances in cardiology.