Impact of High-Dose Irradiation on Human iPSC-Derived Cardiomyocytes Using Multi-Electrode Arrays: Implications for the Antiarrhythmic Effects of Cardiac Radioablation

Figures

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  Figure 1. Illustration of the (a) experimental protocol and (b) parameters assessed using a multielectrode array. Abbreviations: AP, action potential; FPD, field potential duration; FPDc, corrected field potential duration; iPSC-CM, induced pluripotent stem cell-derived cardiomyocyte; MEA, multielectrode array; qPCR, quantitative polymerase chain reaction.

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  Figure 2. Temporal changes of (a) total active electrode, (b) spike amplitude, and (c) spike slope with percent changes within 24 h after high-dose irradiation. (d) Dose–response relationship of these three parameters at 6 h. p-values of dose–response relationship were determined by Pearson’s correlation coefficient; ** p < 0.010 and *** p < 0.001. Values are depicted as the mean ± standard deviation of nwells = 20–24.

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  Figure 3. Temporal changes of (a) field potential duration (FPD), (b) corrected FPD (FPDc), (c) beat rate, and (d) conduction velocity with percent changes within 24 h after high-dose irradiation. Values are depicted as the mean ± standard deviation of nwells = 20–24.

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  Figure 4. Temporal changes in (a) total active electrode, (b) spike amplitude, and (c) spike slope with percent changes until 7 days after high-dose irradiation. Values are depicted as the mean ± standard deviation of nwells = 20–24.

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  Figure 5. Temporal changes in (a) field potential duration (FPD), (b) corrected FPD (FPDc), (c) beat rate, and (d) conduction velocity with percent changes until 7 days after high-dose irradiation. Values are depicted as the mean ± standard deviation of nwells = 20–24.

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  Figure 6. (a) Representative beating patterns of cardiomyocytes after high-dose irradiation. (b) Number of flat T waves in high-dose irradiated groups (nwells = 20–24).

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  Figure 7. Box-and-whisker plots of conduction velocity on days 0 and 7 after high-dose irradiation (nwells = 20–24). Adjusted p-values were determined by one-way analysis of variance followed by Dunnett’s multiple comparison test compared with the control group: **** p < 0.0001. Abbreviation: NS, not significant.

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  Figure 8. Gene expression level of selective human induced pluripotent stem cell-derived cardiomyocytic marker and ion channel genes 7 days after high-dose irradiation. Values are depicted as the mean ± standard deviation of n = 2. All p-values were determined by one-way analysis of variance; ** p < 0.010, *** p < 0.001, and **** p < 0.0001. Abbreviation: NS, not significant.