Figure 3
Propagation of cardiac action potentials (APs) in the 5 × 5 model (5 parallel chains of 5 cells each). First cell of the A-chain (cell A1) was electrically stimulated by a rectangular current pulse (0.5 nA, 0.5 ms) applied internally. PSpice simulation. A: V recording from the A-chain only. B: V recording from the B-chain only. C: V recording from C-chain only. D: V-recording from the D-chain only. E: V-recording from the E-chain only. F: V recording simultaneously from all 5 chains. (The ordinate scale in this panel is slightly different from panels A – E because the computer must list more data numbers at the bottom of the plot, hence compressing the ordinate scale.) All parameters were the standard values (Rjc = 25 MΩ; Rol2 = 100 KΩ). Note that excitation spreads from the A-chain to the B-chain after a delay (from when cell A1 responded) of about 1.4 ms. Also note that once excitation entered the B-chain, it spread more quickly over the 5 cells in that chain. The same was true of the other chains, e.g. in the E-chain the 5 APs were bunched closely together.