Karl Gottfried Konstantin Dehio

Karl Gottfried Konstantin Dehio (27 May 1851, Reval – 26 February 1927) was a Baltic German internist and professor of pathology.

From 1879 to 1883 he was a physician at the Prince of Oldenburg Children's Hospital in St. Petersburg, returning to Dorpat in 1884 as a lecturer at the university.

In 1886, he became a professor of pathology, being chosen university rector in 1918.

From 1890 to 1914 Dehio was editor of St. Petersburger Medizinischen Wochenschrift for Dorpat.

An atropine test known as "Dehio's test" is attributed to him, which states: "If an injection of atropine relieves bradycardia, the condition is due to action of the vagus; if it does not, the condition may be due to an affection of the heart itself".