Different Responses to Drug Safety Screening Targets between Human Neonatal and Infantile Heart Tissue and Cardiac Bodies Derived from Human-Induced Pluripotent Stem Cells

Figure 5

Force-frequency relationship (FFR). (a-d) Force of contraction (FOC) at different stimulation frequencies relative to FOC at 2 Hz for myocardial slices from HLHS (a) and TOF (b) patients as well as for 9 wk (c) and 16 wk (d) old hiPS-CBs. Single measurements from HLHS and TOF tissue slices were further subdivided in positive, biphasic, and negative FFRs (-axis identical within the same group). However, such a separation of FFR pattern was not feasible for hiPS-CBs. (e) Frequency-dependent effects on time to peak (TTP) as well as time to 50% and 90% relaxation of myocardial tissue slices and hiPS-CBs. The -axis differs between myocardial tissue slices and hiPS-CBs. Numbers in the graphs indicate deviations from reported overall numbers at individual experimental steps (TOF, of 8 patients; HLHS, of 6 patients; 9 wk hiPS-CBs, ; and 16 wk hiPS-CBs, ).

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(b)

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