2D Cardiac Conduction Wavefront Map

The heartbeat begins without any nerve signal: sinoatrial (SA) node cells spontaneously depolarize through a slow pacemaker potential, then fire a wavefront that must reach every cell of the heart. This 2D simulator discretizes a schematic map of the atria, AV node, His-Purkinje system and ventricular myocardium into a grid of tissue cells, assigns each region its own real conduction velocity, and solves the exact cell-by-cell arrival time of the wavefront with a Dijkstra fast-marching algorithm — the standard numerical method for this exact problem. Unlike a scripted animation along fixed paths, the wave here finds its own route: block a bundle branch and the simulator reroutes activation through the working ventricular myocardium instead, exactly as happens in a real bundle branch block, visibly widening the QRS. Live PR interval and QRS duration are read directly off the solved activation-time field.