Figure 4.

Traveling waves (TWs) improved the electrical conduction and the contractility of hiPSC-derived close-loop cardiac tissue (iCT)

(A) Activation maps showing the propagation of contractility on day 14, the TWs have been removed before recording to allow spontaneous beating. Each of the points on the axis represent an electrode (8 × 8, spacing 200 μm) on MEA.

(B–D) The conduction velocity (B), Max delay (C) and QTinterval (D) of the contraction of both groups (Mean ± SEM; Conduction velocity: Control: n = 5; TW: n = 4 biologically independent samples from three differentiations; Max delay: Control: n = 4; TW: n = 3 biologically independent samples from two differentiations; QTinterval: Control: n = 10; TW: n = 8 independent biologically samples from four differentiations. ∗∗p < 0.01, ∗∗∗p < 0.001 (Student’s t test).

(E) Representative velocity image of the control and TW groups using a motion analysis system. Red and blue represent high and low velocities, respectively.

(F) Plot of a motion waveform showing contraction and relaxation velocity peaks. The green line marks the time point of the data in (e).

(G–I) Contractile properties of the Control group and TW group. (g) Contraction velocity, (h) relaxation velocity, and (i) acceleration (Mean ± SEM; Control: n = 10; TW: n = 13 biologically independent samples from three differentiations). ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001 (Student’s t test).