The 125th anniversary of the His bundle discovery.

In 1893, Wilhelm His Jr. was the first to describe the AV (atrioventricular) bundle of the vertebrate heart, which now bears his name. Moreover, prior to the turn of the century, W. His Jr. had proved the function of the AV bundle by transection experiments in animals, and had interpreted Adams Stokes disease as heart block due to pathological changes within the bundle. In this way, he was ahead of his time. While clinical interest was limited to the bundle as the location of an AV block in the first half of the 125 years, it has gained attractiveness since then as a target of diagnostic and therapeutic procedures. The introduction of His bundle electrography relaunched the interest in cardiac arrhythmias. Once the AV bundle could be localized clinically, its ablation, and in recent times its permanent stimulation, became options in the therapy of well-defined arrhythmia and conduction problems.