Fig. 6.

Overview of maturation-dependent changes in cellular Ca²⁺ dynamics and electrophysiology which drive action potential (AP) characteristics in experimental and in silico human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM). A Plots of the experimental data for all measured electrophysiological cellular parameters in aging hiPSC-CM. The red line indicates the in silico output of expected results demonstrating non-linear maturation-dependent characteristics. B Simulated steady-state AP traces at 0.5 Hz in d30 and d70 modelled hiPSC-CM. The stimulus current (I_stim) was set to − 120 μA/μF and the hyperpolarising current (I_hyper) was set to 0.2 μA/μF. C Representative experimental AP traces in early (left) and late hiPSC-CM (right). D Comparison of experimental and model AP properties during 0.5 Hz pacing: resting membrane potential (RMP; left) and AP duration at 90% repolarisation (APD₉₀; right). Experimental data are mean ± SEM. *P < 0.05. Symbols represent separate differentiations. n/N = number of hiPSC-CM/differentiation