A case of Adams-Stokes' disease which I had the opportunity to observe presented symptoms of heart block. There were from three to four auricular contractions to one ventricular beat. During the attacks the ventricle stopped entirely, while the auricular rhythm kept on undisturbed. The patient died after twenty-four hours.
In view of the experimental work on heart block done by Erlanger and Hering I felt justified in diagnosing a lesion of the auriculo-ventricular bundle of His.
The postmortem was limited to the heart. Macroscopically no lesion could be detected, but the microscopic examination by Dr. Ophüls showed scar formation in and around the bundle of His just below the membranous septum.