Morphologic variations and aging in the atrioventricular conduction system of large breed dogs.

摘要: The microscopic anatomy of the atrioventricular node, bundle His, both branches and surrounding fibrous cardiac skeleton was studied in 40 large breed dogs various ages. In AV conduction system all over five years age there an increase connective tissue, infiltration adipose loss fibers focal fibrosis extending from central body. Fibrosis seen summit interventricular septum posterior to node Chondroid metaplasia consistently observed body root aorta dogs, including ten Doberman Pinschers This varied a few chondroblasts chondrocytes mature with mineralization. Bone formation eight dogs. These changes appeared close approximation above His. No degenerative were bundle. Approximately one-half older had thickened medial intima proliferation small coronary arterioles supplying node. results this study suggest that presence cartilage bone is normal occurrence at