Figure 3: The calculated transmembrane potential during or following unipolar stimulation of cardiac tissue. The four rows correspond to the four mechanisms of stimulation: cathode make (CM), anode make (AM), cathode break (CB), and anode break (AB). The fibers are horizontal, and the transmembrane potential is shown by color. An 8 mm by 8 mm region of tissue is shown, and the black rectangle at the center of each region is the position of the electrode. The numbers along the top of the frame are the times in milliseconds [15].