Steady -state and nonsteady-state action potentials in fibrillating canine atrium: Alternans of action potential and late phase 3 early afterdepolarization as a precursor to atrial fibrillation

Abstract

The mechanism(s) responsible for immediate recurrence of atrial fibrillation (IRAF) after cardioversion is largely unknown. We hypothesized that rapid rates of excitation during atrial fibrillation (AF) induce calcium loading and abbreviate action potential duration (APD), which in turn promote APD alternans and delayed and/or early afterdepolarization after restoration of sinus rhythm.