Institute of Cardiovascular Sciences, University of Manchester, Core Technology Facility, 46 Grafton St, Manchester, UK.
Heart Rhythm. 2013 Feb;10(2):297-304. doi: 10.1016/j.hrthm.2012.10.020. Epub 2012 Oct 22.
The structure and functioning of the atrioventricular (AV) node has remained mysterious owing to its high degree of complexity. In this review article, we integrate advances in knowledge regarding connexin expression in the AV node. Complex patterning of 4 different connexin isoforms with single channel conductances ranging from ultralow to high explains the dual pathway electrophysiology of the AV node, the presence of 2 nodal extensions, longitudinal dissociation in the penetrating bundle, and, most importantly, how the AV node maintains slow conduction between the atria and the ventricles. It is shown that the complex patterning of connexins is the consequence of the embryonic development of the cardiac conduction system. Finally, it is argued that connexin dysregulation may be responsible for AV node dysfunction.
房室（AV）结的结构和功能由于其高度复杂性而一直是个谜。在这篇综述文章中，我们整合了有关 AV 结中连接蛋白表达的知识进展。4 种不同连接蛋白亚型的复杂模式，其单一通道电导率从超低到高，解释了 AV 结的双径路电生理学、2 个结延伸的存在、穿透束中的纵向分离，以及最重要的是，AV 结如何在心房和心室之间维持缓慢传导。研究表明，连接蛋白的复杂模式是心脏传导系统胚胎发育的结果。最后，有人认为连接蛋白失调可能是 AV 结功能障碍的原因。
