Abstract: An animated cardiac activation map can be created by simulating particle flow over a three-dimensional representation of a cardiac surface. In particular, an electroanatomical mapping system can simulate and display particle flow through a conduction velocity map for the cardiac surface, with the conduction velocity map defining a conduction velocity vector field over the cardiac surface. Particles may be spawned randomly and/or according to a local activation timing map for the cardiac surface. Likewise, particle simulation may be displayed for a preset time interval and/or for a time interval determined by the local activation timing map. Particle simulation may also end if a particle encounters a line of block. Regions of dispersion or breakout can also be identified using the conduction velocity vector field.