Figure  1: Spiral-wave solution and tip-trajectory evolution for the "normal" guinea-pig ventricular model. (a) Isochrones of the wavefront shown every 1ms. A total of 105 isochrones are plotted (average rotation period is approximately 100ms throughout the simulation). (b) Spatial voltage distribution (V® z-axis) snapshot. The numbers at the bottom of the plot indicate the V-level contours and the asterisk the position of the spiral tip. (c) Tip trajectory evolution for the "normal" guinea-pig ventricular model (standard parameter values used see [5]). The region shown here is 5.5× 5.5 mm² . The enlarged panel shows tip trajectory evolution for 1100ms starting at t=1900ms to remove transients. Panels a-k show the same evolution in segments of 100ms. The horizontal solid bar in the enlarged and the first panel is 1mm wide.