<p>Application of the calcium channel blocker nifedipin completely stopped action potential generation in day 60 hiPSC-CMs (A) and day 60 hESC-CMs (B) at a concentration of 10 µM. Application of 1 µM nifedipin resulted in a strong shortening of the action potential. Application of lidocain could completely prevent action potentials in hiPSC-CMs at a concentration of 50 µM (C), in hESC-CMs 1000 µM abrogated action potential generation.</p
