Kent Bundles in the Anterior Septal Space

Kent bundles in the anterior septal area of the heart occupy a region of complex morphology. In this study, the anatomical characteristics of the area were reviewed by the dissection of 12 human hearts and then an analysis was done of the results of operation in 15 patients with Kent bundles in this location. One important anatomical finding was the relationship of the atrial septum, the right fibrous trigone, and the underlying membranous ventricular septum to the atrioventricular node and the His bundle. The normal components of the conduction system are protected from injury at operation by encasement in these structures. At operation, the accuracy with which retrograde endocardial mapping could identify the Kent bundle was demonstrated in 8 patients who had Kent bundles clearly shown to be within 2 to 5 mm of the His bundle. Kent bundle interruption in 13 patients was achieved by a precisely placed incision and dissection, and in 2 patients by cryothermia. In 1 of these 2 patients, both the His bundle and the Kent bundle were interrupted when cryothermia was used at a second operation. This study indicates that a Kent bundle and His bundle can be within 2 mm of each other, judging their positions by retrograde endocardial mapping. Final proof of the Kent bundle's location is demonstrated by interruption. With the protection afforded to the His bundle by encasement in the right fibrous trigone, surgical interruption of the adjacent Kent bundle can be accomplished without injury to the His bundle.