This figure illustrates a stationary spiral wave on the left, and a drifting spiral wave on the right. Spiral waves are a type of functional re-entry that occurs in the setting of closely spaces fibers with different electrical properties but without an anatomically defined circuit. This has also been referred to as anisotropic and leading circle re-entry.
Spiral waves are one of the mechanisms underlying atrial and ventricular fibrillation and a cause of the polymorphic ventricular tachycardias associated with acute myocardial ischemia and the congenital and acquired long QT syndromes.