AV Node Function during Atrial Fibrillation

The A V node is a small cluster of cells, hardly visible in small rodents, and reaching the size of a chestnut in whales. In adult humans, it has the size and shape of an orange pit. Few, if any, structures of such small size in the mammalian body have such vital functions as does the A V node. Our understanding of the functions of the human A V conduction system in general, and of the A V node in particular, depends to a large extent on clinical empiricism and extrapolation of animal data. In thls chapter we will, in the footsteps of Purkinje, attempt to analyze mechanisms of AV node transmission in atrial fibrillation (AF) using empirically obtained clinical data and basic electrophysiologic prindples.