Figure 8.

Detection of action potential conduction slowing by Na channel blockers. A–C, Mexiletine is a sodium channel blocker that slows impulse conduction velocity (CV). Quantification of CV indicates that our assay can detect significant slowing of impulse propagation in all 3 cell lines. D–F, Disopyramide is a sodium channel blocker that also slows impulse conduction. Conduction slowing by disopyramide was detected in the CDI and MCH cell lines, but not CLS. G–I, Quinidine is a sodium channel blocker and conduction slowing was detected in CDI and MCH hiPSC-CMs in this assay, but not the CLS cells. All data expressed as mean±SEM. *Significant difference of the mean within a group, analyzed by 1-Way ANOVA, p < .001.