Figure 3. Analysis of E-4031, a hERG K⁺ channel blocker known to prolong the QT interval.

(A) Representative traces of the contractile profile from the brightfield analysis show a pronounced contraction elongation at the highest tested concentration (30 nM). (B) At the concentrations of 1, 3, and 5 nM, the SVM accuracies were approximately 50%, similar to those of the control experiments. For the 10 and 30 nM concentrations, the SVM accuracies increased to 79.82 ± 0.77% and 83.55 ± 1.08% respectively. This increase among accuracies suggest the compound had a cardio-modulating effect on the cells at those given concentrations (n = 15). (C) Using the GCaMP6 method, significant changes in the beating rate were seen at the 30 nM concentration (p = 0.0175). (D) For the SR₉₀ parameter, significant differences were detected at the 10 and 30 nM concentration (p = 0.0355 and p ≤ 10⁻⁴ respectively) (n = 15). *p < 0.05, ***p < 0.001.