Calcium dysregulation underlies phenotypic diversity in LQT2: Insights from induced pluripotent stem cell-derived cardiomyocytes of a KCNH2 p.Y427H family trio

Figure 4 Calcium handling and field potential characteristics of family trio induced pluripotent stem cell-derived cardiomyocytes. A: Representative I_CaL from the father induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) (a1), proband iPSC-CMs (a2), and mother iPSC-CMs (a3). Panel shows the I-V curve of I_CaL (a4), panel presents the inactivation curve of I_CaL (a5), and panel shows the statistical data of I_CaL density at a membrane potential of +10 mV (a6). Data represent n = 7 from 3 independent differentiations; B: Representative calcium transient waveforms from the three groups (b1). Statistical analysis of the calcium transient peak amplitude (b2). Statistical analysis of the calcium transient at 90% decay (CaTD₉₀) (b3). Data represent n = 15 regions of interest from 3 independent differentiations; C: Representative field potential waveforms from the three groups (c1). Statistical analysis of the field potential duration and corrected field potential duration (c2 and c3). Data represent n = 15 from 3 independent differentiations. iPSC-CMs: Induced pluripotent stem cell-derived cardiomyocytes; CaT: Calcium transient; CaTD: Calcium transient duration; FP: Field potential; FPD: Field potential duration; cFPD: Corrected field potential duration.