Figure 5.

Spatial distribution of voltage and Ca in large tissue sizes. (A) Snapshot of $s_{ij}$ and $\text{Δ}{a}_{ij}$ on a tissue of $150\times 150$ cells. All cells are paced simultaneously at $T=360ms$ and the snapshots shown are computed using the 99th and 100th beats. Insets show the AP for the last 4 beats at the indicated cells on the array. (B) A $150\times 50$ strip paced at the bottom edge. A snapshot of $s_{ij}$ is computed using the Ca transients at beat 30 and 31. The three images below are voltage snapshots at 2-ms intervals following the 30th paced beat. The green line denotes the APD nodal line where $\text{Δ}{a}_{ij}=0$. (C) Snapshots of the voltage distribution on a $150\times 150$ cell tissue that is paced on a five-cell strip at the bottom edge. The snapshots shown are at the indicated times during the 30th paced beat. The snapshot for $s_{ij}$ is computed using the 31st and 30th beats. (D) Same simulation but Ca waves have been eliminated by increasing the threshold for Ca wave nucleation by increasing the parameter $p_b^{\ast }$ (see Supporting material for a detailed description) from $0.45$ to $0.9.$ The parameter $p_b^{\ast }$ denotes the threshold for Ca sparks, which are triggered at the cell boundary, to nucleate a Ca wave that propagates to the cell interior. (E) Same simulation but where the recovery from inactivation of $I_{Ca}$ has been reduced by a factor of two.