Walter Karl Koch was a German surgeon (Dortmund, Germany, May 3 1880- ? ), best known for the discovery of Tawara's node , the atrioventricular node which is the beginning of his bundle about the auricular-ventricular .

Educated at Freiburg im Breisgau and at the Berlin Kaiser-Wilhelms-Akademie , he obtained his doctorate in 1907 at Freiburg, and as a military physician was posted at the Heidelberg pathological institute and the II medical clinic in Berlin. Here he was habilitated for general pathology and pathological anatomy in 1921.

After being named a professor in 1922, he worked as head of department at the Krankenhaus Westend.

Koch became known for his work on the motor centres of the heart, and coined the term "sinus node."