[Embryological duplications of the node-bundle of His : its pathological rôle].

A histological study by the method of seriated sections in one case of "double-outlet left ventricle" made it possible to confirm and to describe the embryology of the nodal-His junction: not only the atrio-ventricular node (AV N) but also the His bundle (H) have a double origin, atrial and ventricular. Fusion of these two buds, inexistant in the "lone ventricle" is certainly imperfect. Two macroscopically normal hearts provided examples of nodal buds in one case, of a persisting cleft between the two His buds in the other.