FIGURE 4.

Effect of PDE inhibitors on the potency of isoprenaline to induce positive inotropy in hiPSC‐CM EHTs. Mean with 95% confidence interval of normalized force data. Nonlinear regression curve fit with variable Hill slope. Vehicle: DMSO 0.1% (n = 45; 6); Mil: milrinone (10 μM, n = 17; 3); Cil: cilostamide (300 nM, n = 22; 3); Rol: rolipram (10 μM, n = 10; 2); Tad: tadalafil (10 nM, n = 10; 2); IBMX (10 μM, n = 15; 3), n; n = number of EHTs; number of differentiation batches, the number of EHTs was used for statistics. Curve fitting was performed with GraphPad Prism software 5.0. Two constrains (lowest value = 0, highest value = 100) were applied. P < .05, significantly different as indicated