Fig. 1. Action potential (AP) characterization of human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). AP was elicited by minimal current injection to overcome the threshold in the current-clamp mode. (A) Representative traces of nodal-like (top), atrial-like (middle), and ventricular-like (bottom) APs in human iPSC-CMs. The AP subtypes of human iPSC-CMs are classified based solely on AP morphology, with ventricle-like CMs having longer AP duration (APD₉₀ > 600 ms) than both nodal- and atrial-like CMs (APD₉₀ between 500 and 600 ms). The distinction between nodal- and atrial-like APs is made based on differences in resting membrane potential (RMP), total amplitude (TA), and upstroke velocity (dV/dt_max). (B) The relative proportion of three different AP subtypes in human iPSC-CMs. n = 80. (C) The parameters of the three AP types recorded in human iPSC-CMs. Error bars, SEM. Student’s t-test, *p < 0.05.

Korean J Physiol Pharmacol 2023;27:267-275 https://doi.org/10.4196/kjpp.2023.27.3.267

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