Depolarization(redirected from atrial premature depolarization)
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the decrease in the difference in potentials during the resting state (so-called resting potential) between the internal and external sides of the membrane of a living cell. In nerve cells and their processes, as well as in muscle fibers, depolarization is one of the most important components of the process of excitation. Stable depolarization may occur experimentally or in certain diseases as a result of direct damage to the membrane or disruption of metabolism.