<P> An important property that is unique to the AV node is decremental conduction, in which the more frequently the node is stimulated the slower it conducts . This is the property of the AV node that prevents rapid conduction to the ventricle in cases of rapid atrial rhythms, such as atrial fibrillation or atrial flutter . </P> <P> The AV node's normal intrinsic firing rate without stimulation (such as that from the SA node) is 40 - 60 times / minute . This property is important because loss of the conduction system before the AV node should still result in pacing of the ventricles by the--slower--pacemaking ability of the AV node . </P> <Ul> <Li> Atrioventricular conduction disease (AV block) describes impairment of the electrical continuity between the atria and ventricles . It occurs when the atrial depolarization fail to reach the ventricles or is conducted with an abnormally long delay . It can result from an injury or be a genetically inherited disorder . </Li> <Li> Atrioventricular nodal re-entry tachycardia . </Li> <Li> Cystic tumour of atrioventricular nodal region (CTAVN) CTAVN is of endodermal origin and occurs exclusively in the area of the AV node, tricuspid valve, and interatrial septum . </Li> </Ul> <Li> Atrioventricular conduction disease (AV block) describes impairment of the electrical continuity between the atria and ventricles . It occurs when the atrial depolarization fail to reach the ventricles or is conducted with an abnormally long delay . It can result from an injury or be a genetically inherited disorder . </Li>

Slowing or no transmission of impulses between atria and ventricles