[Apparent auricular paralysis and disorders of auriculo-ventricular conduction. anatomo-clinical study].

Correlation between the endocardial electrocardiographic recording and the histological findings of the conduction pathways in one case of apparent atrial standstill makes it possible to state the following facts: 1. The presence of a supranodal block through an intraatrial conduction disturbance. 2. The presence of James' fibres by-passing the upper part of Tawara node. 3. The functional character of these James' fivres which constitute, in view of the presence of lesions of the upper part of the Tawara node, the only possible pathway from the atria to the ventricles in this case. 4. The possibility to record the action potentials of James' fibres in that exceptional case. The histological examination made it possible also to recognize the anatomical lesions responsible for the idiopathic dilatation of the right atrium and of the apparent atrial standstill which represented the end-stage of an atrial rhythm disease.