Walter Eduard Carl Koch (1880–1962), German physician, anatomist, and pathologist. Born in Dortmund, Germany, studied medicine at the University of Freiburg and the Kaiser Wilhelm Academy in Berlin, attaining his doctorate in 1907.
He served as a military physician, and later at the Kaiser Wilhelm Academy and in Berlin. Koch specialized in pathology and pathological anatomy and was appointed professor in 1922. Later he became head of the Pathology Department at the Westend Hospital in Berlin and held academic positions after World War II, including a professorship at the newly reconstituted Free University of Berlin. He died in 1962.
He is remembered by the eponymous “triangle of Koch, “site for the atrioventricular node. Although he never referred to this area as a triangle, or used his name to refer to this area, he described it as we know it today in his 1922 publication “Der Funktionelle Bau des Menschlichen Herzens” (The functional structure of the human heart).
Plate X.1 by Walter EC Koch (1922)
In Plate 10.1 Koch shows a photograph of the right atrium where he has drawn the “Tawara’schen Knotten”- an early name for the atrioventricular node (knot of Tawara) – and he describes it as follows: “Vorhofsfeld im rechten Vorhof, vom Sinusstreifen als Fortsetzung der Valvula Eustachii, von der Coronarvenenmündung und dem Ansatz der Tricuspidalisiklappe umsäumt, in weichem der Anfangstait des Reizleitungssystems (schematisch eingezeichnet) gelegen ist: Sinusstreifen und Tricuspidalis treffen sich an der Pars membranacea dort, wo der Stamm den Knoten verläßt” (The atrial region in the right atrium, bordered by the sinoatrial band, a continuation of the Eustachian valve, by the coronary vein (sinus) orifice and the insertion of the tricuspid valve, in which the initial stage of the conduction system (schematically shown) is located: the sinoatrial sinus and the tricuspid valve meet at the pars membranacea where the trunk leaves the node.) The handwriting on the image is by Koch himself.
Note that Koch does not mention the tendon of Todaro as a landmark in this description (although Todaro’s tendon is mentioned in this publication), and Koch calls it the “sinoatrial band").
The term "triangle of Koch" refers to a triangular area in the right atrium with defined anatomical boundaries:
• Medial border: the tendon of Todaro
• Inferior border: the tricuspid valve leaflet
• Posterior border: the orifice of the coronary sinus.
The apex of this triangle corresponds to the location of the atrioventricular node.
Note: In spite of my efforts, I could not find a photograph or a portrait of Walter E.C. Koch. Dr. Miranda.
Sources:
1. "Remembering the canonical discoverers of the core components of the mammalian cardiac conduction system: Keith and Flack, Aschoff and Tawara, His, and Purkinje" Icilio Cavero and Henry Holzgrefe Advances in Physiology Education 2022 46:4, 549-579.
2. "Tratado de Anatomia Humana" Testut et Latarjet 8th Ed. 1931 Salvat Editores, Spain
3. Anderson RH, Sánchez-Quintana D, Nevado-Medina J, Spicer DE, Tretter JT, Lamers WH, Hu Z, Cook AC, Sternick EB, Katritsis DG. . The Anatomy of the Atrioventricular Node. J of Cardiovasc Development and Disease. 2025; 12(7):245.
4. Koch, Walter “Der Funktionelle Bau des Menschlichen Herzens” Urban & Schwarzenberg. 1922. Berlin