Rapid Electrical Stimulation Reduces Ca2+ Transients and Cav1.2 Expression in hiPSC CM
(A) Representative Ca2+ transients recorded using fluo-4-labeled hiPSC CMs unpaced (CTRL) and paced at 1 or 4 Hz for 8 hr. Note the abnormal secondary Ca2+ release during decay phase (inset).
(B) Bar graphs showing magnitude of Ca2+ transient expressed as F/F0 and rate of transient decay (tau, ms). ∗p < 0.0001 compared to 1 Hz and CTRL. n = 10 independent recordings, each group.
(C) Cav1.2 expression, measured by RT-qPCR, in hiPSC CMs subjected to 1 and 4 Hz electrical stimulation.