AURICULOVENTRICULAR HEART BLOCK DUE TO BILATERAL BUNDLE-BRANCH LESIONS

Abstract

Lesions of the main branches of the bundle of His as a cause of auriculoventricular heart block have not been sufficiently emphasized, although this cause ranks in importance with lesions of the bundle of His itself, such as fibrosis, calcification and gummatous infiltration. The reason for the lack of recognition of the importance of this cause of heart block lies undoubtedly in the paucity of careful histopathologic studies in cases of heart block. Mahaim,¹ whose work is outstanding in this field, in completely reviewing the literature concerning histopathologic studies of the conduction system in cases of complete heart block was able to select only 25 cases, including 4 of his own, in which the studies were complete and entirely satisfactory in all respects. He selected 11 more cases the reports of which showed only insignificant defects and which could be considered relatively satisfactory. All of the other 79 cases