Fig 4. The expected number of open channels in the linearized mean-field CN (LCN) model predicts spark probability.

(A) Expected number of open channels (E[N _O]) of the LCN model at t = 8 ms strongly correlated with p _S of the 3D spark model (R ² = 0.934). Data shown for a collection of 15 clusters. (B) E[N _O] also correlated with λ ₁ (red), but not with the number of channels in the cluster (n, black). Data points are from collection of 107 clusters. (C) Time dependence of the expected number of open channels for different initiating RyR2s ($\mathrm{\text{E}}\left[{\underset{¯}{n}}_O\right]$) on edge of the cluster (blue), in the interior (red), and the average (E[N _O], black) for the cluster shown in the following panel. (D) Heatmaps of $\mathrm{\text{E}}\left[{\underset{¯}{n}}_O\right]$ (left) and p _S estimated using the 3D spark model (right) illustrates intra-cluster gradients in spark probability.