Figure 2.

Prominent effects of I_to among other K⁺ currents. (A) APD prolongation from the downregulated repolarizing K⁺ currents present in failing human cardiomyocytes with decreased I_to (blue) showing a loss of the distinctive “notch” in the action potential shape. (B) Roughly two-fold increase in time-to-peak Ca²⁺ transient from 0.02 to 0.04 s duration was observed. (C) I_LCC peak density also decreased roughly 30–35%, respectively, by the effects of I_to alone. (D) RyR open probability is reduced ~20–25% and (E) delayed kinetics of Ca²⁺ release from the SR by I_to.