Bradycardia historical perspective

Overview

In 1839, Jan Evangelista Purkinje discovered a net of gelatinous fibres in the subendocardium of the heart.
Walter Gaskell in the 1880s observed that the impulse of the heart began in the sinus venosus, and that this region had the most rhythmic ability.
A conducting bundle between the atrium and the ventricle was found by Wilhelm His, Jr in 1893.
In 1906, Sunao Tawara found a “complex Knoten” of tissue at the proximal end of the His bundle. He concluded that this was the inception of an electrical conducting system that continued from the AV node through the bundle of His, divided into the bundle branches, and terminated as the Purkinje fibres.
In 1906, Martin Flack, a medical student, reported to Keith the first observation of the mammalian sinoatrial node (SAN).