KCNA3 and chronic obstructive pulmonary disease: Moreover, osimertinib has been reported to simultaneously block the hERG potassium channels, a phenomenon associated with QT prolongation; cardiac sodium channel Nav1.5, which is associated with slowed conduction; and L-type calcium ion channels, which trigger excitation-contraction coupling, modulate the action potential shape, and are involved in cardiac arrhythmia.