Arthur Douglas Hirschfelder (September 29, 1879 – October 11, 1942) was a cardiologist who interned under William Osler at the Johns Hopkins University School of Medicine in Baltimore, Maryland where he later became the head of a physiological laboratory in the Department of Medicine. He is best known for his research on local anesthesia and for treating heart illnesses. Hirschfelder is also widely known as being the first full-time cardiologist at Johns Hopkins University. Biography Personal life Parents Arthur Douglas Hirschfelder was born on September 29, 1879 in San Francisco, California to Clara Honigsberg and physician Joseph Oakland Hirschfelder. His father, Joseph, moved from Germany to California in 1843 where he attended University of California and graduated the first in his class. Later, he became a professor of medicine at Cooper Medical College, now known as the Stanford University School of Medicine, where he became the first professor to highlight the importance of accurate bedside records. Joseph played a significant role in Arthur's choice of career, greatly influencing his desire to become a physician. His father Joseph Hirschfelder passed away at the age of 65 on July 4, 1920 due to a sudden case of heart failure. Family On June 26, 1905, Arthur married May Rosalie Strauss and on March 5, 1907 May Strauss gave birth to their first child, Rosalie Claire Hirschfelder. Four years later, on May 27, 1911, Arthur Hirschfelder and May Rosalie Strauss gave birth to their son, Joseph Oakland Hirschfelder. Education Arthur D. Hirschfelder graduated from high school at the age of thirteen, and continued his education at the University of California, Berkeley where he graduated with a B.S. in zoology in 1897. Afterwards, he moved to France and continued his studies at the Pasteur Institute before spending and additional two years in Germany at the Heidelberg University to study medicine until 1899. Hirschfelder later pursued medicine at the Johns Hopkins University School of Medicine, where he received his M.D. in 1903. Hirchfelder remained at Hopkins for a year afterwards, interning for William Osler before spending the next year working as a resident under his father at the San Francisco General Hospital. Career Arthur Hirschfelder returned to Johns Hopkins as chief of the new physiological laboratory of the Department of Medicine in 1905. It was at Johns Hopkins that Hirschfelder pursued research on the electrocardiogram (also known as the EKG or ECG) in humans and became