Atrial electogram morphology in atrial fibrillation

The morphology of unipolar electrograms recorded during atrial fibrillation reflect different patterns of conduction, as demonstrated by the isochrone maps. Black arrows indicate the direction of activation. Single potentials are indicative of rapid uniform conduction. Short doubles result from collision of the wavefronts along a line of collision (map A). Long doubles are due to conduction block (Map B). Fragmented electrograms refect multiple discrete deflections that may result from impulse conduction around a pivotal point (map C) or from slow or delayed conduction (map D).