Resonance induced pacemakers: a new class of organizing centers for wave propagation in excitable media.

Propagation of waves in an extended excitable system is considered. It is shown that traveling wave fronts can be triggered and maintained via local periodic modulations of an appropriate system parameter. For a finite range of perturbation frequencies, this new class of pacemakers introduces spatiotemporal self-organization in an otherwise quiescent medium. Excitation waves of activity similar to those observed in heart tissue cultures and other biological preparations can emerge in the presence of these pacemakers.