Figure 7.

Characterization of Contracting Cardiomyocytes

(A) Arrow-based display of the directed contractions of cardiomyocytes (passage 0). (B) Heatmap depicting the time-averaged magnitude of motion in the x and y directions. An increase of movement is indicated by colors from blue to red. (C) Representative display of beating velocity (micrometers per second) during the recorded time of 30 s. Blue dots indicate contraction, and red triangles indicate the relaxation. Beat rate and frequency (mean ± SD) of iPSC-derived cardiomyocytes were calculated via motion tracking (n = 4). (D) Ca²⁺ imaging of cardiomyocytes. Representative images of every 200 ms are shown. White arrows indicate the position of Ca²⁺ transients. (E) Dose-response curves of isoproterenol- and nifedipine-treated cardiomyocytes (mean ± SD; n = 3).