Epicardially Placed Bioengineered Cardiomyocyte Xenograft in Immune-Competent Rat Model of Heart Failure

Figure 7

Intracellular calcium flux and mechanical contraction. Superimposed colorized tracings depicting the (a) height-normalized intracellular calcium flux waveforms from hiPSC-CMs and fibroblasts integrated into an engineered cardiac graft and the (b) height-normalized mechanical contraction waveforms from the same graft in milliseconds (ms). In black, the graft is beating at its spontaneous (spont) rate. The graft was then paced with at incrementally increasing rates between one Hertz (1 Hz) and three Hertz (3 Hz) to characterize the engineered cardiac graft’s flux-frequency and force-frequency relationships. (c) The original intracellular calcium and mechanical contraction tracings, with arbitrary units on the -axis and time in seconds on the -axis. A decreasing calcium-flux and contraction amplitude is observed with increasing pacing frequency (negative flux-frequency and force-frequency relationships), suggesting functional deficit in the contractile machinery in this engineered cardiac graft.

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