Figure 1. Single atrial cell action potential, Ca²⁺ transient and APD restitution.

A, the AP produced by the modified CRN cell model, simulated at a BCL of 1000 ms (continuous line) and the intracellular Ca²⁺ concentration change (Ca²⁺ transient) during the AP trace (dotted line). B, APD restitution for the model, compared to available experimental data (Dawodu et al. 1996; Bosch et al. 1999; Dobrev & Ravens, 2003).