Sensitivity of Rabbit Ventricular Action Potential and Ca²⁺ Dynamics to Small Variations in Membrane Currents and Ion Diffusion Coefficients

Figure 7

Verification of Ca²⁺ and Na⁺ diffusion sensitivity predictions. Steady-state AP and Ca²⁺ transients (recorded 9-10 s) in three non-SR compartments in response to 1 Hz stimulus. The relative changes in APD₆₀ and Ca²⁺ peaks (see Insets also) are consistent with predictions generated by Nimrod/E and PLS with respect to 10% increases in Ca²⁺ and Na⁺ diffusion constants. Control diffusion coefficients (black solid line) and 10% increases in 𝐷_Ca(jct-SL) (black dashed line), 𝐷_Ca(SL-𝑖) (black dash-dot line), 𝐷_Na(jct-SL) (gray dotted lines), 𝐷_Na(SL-𝑖) (light gray dotted lines).

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