Fig. 5. Effect of ivabradine on human APs from iPSC derived cardiomyocytes. (a) Example of ventricular-like action potentials as obtained from current clamp measurements in iPS cell derived human cardiomyocytes under control conditions and after 1 minute equilibration with either 1 or 10 µM of ivabradine (1 Iva, and 10 Iva, respectively). (b) A summary of the AP duration measured at 90% repolarisation (APD90) as derived from experiments shown in (a). (c) Summary of the maximal depolarisation value reached by the AP. (d) Summary of the maximal upstroke velocity as derived by taking the maximum of the first time derivative, max dV/dt. All data are displayed as mean +- SEM (n = 8 and 7, for 1 and 10 Iva, respectively). Statistical significance for 1 and 10 Iva versus control was tested with a paired Student's t-test; ns, not significant.