The electrophysiological substrate of atrial fibrillation

The electrophysiological substrate that predisposes the human atrium to sustain atrial fibrillation is incompletely understood. However, abnormalities of atrial size, refractory period and conduction are important precursors to this arrhythmia. The propensity of various disease states, cardioactive drugs and the autonomic nervous system to potentiate atrial fibrillation may be explained by changes in these electrophysiological properties.