PATHOLOGY
Schoenberg [Footnote: Schoenberg: Frankfurt. Ztschr. f. Pathol., 1909, ii, 4.] finds that in auricular fibrillation there are definite signs in the node, such as round cell infiltration, showing inflammation, a fibrosis of the tissue, and perhaps a sclerosis of the blood vessels of that region. He also found that compression of this nodal region of the auricle from some growth or other disturbance in the mediastinal region could cause auricular fibrillation.
Jarisch [Footnote: Jarisch: Deutsch. Arch. f. klin. Med., 1914, cxv, 376.] finds by personal investigations and by studying the literature that the node showed pathologic disturbance in less than half the cases. Consequently, although a pathologic condition of the node is a frequent, and perhaps the most frequent, cause of auricular fibrillation, other conditions, especially anything which dilates the right auricle, may cause it.