Abstract

Elimination of spiral waves prevents transition to chaotic start in excitable media of different physicochemical nature. In cardiac muscle, to prevent cardiac death, the spiral waves are usually removed together with all propagating waves by a strong electric shock: 5 kV, 20 A (''defibrillation''). We have found an approach to extinguish spiral waves without destroying normally propagating waves. Chemical excitation waves in a spatial open reactor with the Belousov-Zhabotinsky reaction controlled by light were used as an experimental model. We found three different scenarios, depending on the rate of the light change. (i) When the light intensity was increased immediately, the spiral wave was eliminated. (ii) When it was increased slowly enough, the spiral wave survived, increasing its core and diminishing its rotation rate. (iii) When it was increased gradually, at an intermediate rate, the spiral wave survived, but multiple wave breaks appeared at the periphery. Computer modeling has shown that the results obtained are generic and relevant for excitable media of various nature.