Impaired electrical conduction (regulating the heartbeat) between the atria and the ventricles of the heart.
A condition in which the depolarization impulse is delayed or blocked at the atrioventricular (A-V) node or a more distal site, as in the A-V bundle or bundle branches. AV block can be partial or complete. There are several degrees: First-degree block is due to prolonged A-V conduction; electrocardiograms show a characteristic prolonged PR interval. Second-degree blocks are intermittent (i.e., some, but not all, A-V impulses are transmitted to the ventricles). Third degree block, also known as complete AV block, is present when no atrial impulses are conducted to the ventricles.