English: Spiral-wave dynamics in the presence of an EAD clump. Video showing how the presence of an EAD clump anchors the spiral to the clump and can disturb the periodicity of the motion of the spiral. The top panel shows the spiral motion in the absence of an EAD clump. The bottom-left and the bottom-right panels show the spiral motion in the presence of EAD clumps of radii R = 2 cm, and R = 3 cm, respectively. The spiral anchored to the small clump (R = 2 cm) rotates in a periodic motion, whereas the spiral anchored to the large clump (R = 3 cm) does not exhibit a periodic motion, but rather rotates in a quasiperiodic manner (cf. Fig 16). The EAD clumps trigger excitations that block the progression of the spiral tip and, in turn, generate a new spiral tip. For this video, we use 10 frames per second with each frame separated from the succeeding frame by 20ms in real time.