Effect of the Membrane Environment on Pharmacologic Inhibition of hERG K Channel Activity.

Background: hERG encodes K11.1 voltage-gated K channels, which generate the rapidly activating delayed rectifier K current that contributes to repolarization of the cardiac action potential. In addition to being targeted by many class III antiarrhythmic agents, these channels are also inhibited by a multitude of other pharmacological compounds, which can produce acquired long QT syndrome, leading to polymorphic ventricular tachycardia.