Biochem/physiol Actions GPV574 is a derivative of the Class 1C antiarrhythmic drug propafenone. GPV574 inhibits the delayed rectifier K+ channel HERG with similar affinity and time constant as propafenone (IC50 = 5 mM), but unlike the parent compound, does not remain permanently trapped in the channel pore. After wash-out of GPV574, channel activity is recovered within 60 seconds. |