Spiral waves and the heart

The human heart normally beats at a fairly regular rare of once per second. Under abnormal conditions, however, the heart may beat irregularly, at fast rates, leading quickly to death. The most dangerous of these irregular heart rhythms are due to recirculating electrical waves of activity. However, the detailed mechanisms of these ''reentrant arrhythmias'' are unclear. It has been suggested that these recirculating waves are spiral waves. This review article presents recent studies of the heart providing evidence that reentrant arrhythmias result from spiral waves of electrical activity. Spiral waves are generic to many excitable media, therefore the theory of spiral waves is well developed and also reviewed herein. Many of the predictions of spiral wave theory are being realized in the heart and leading investigators in new directions.