Which cardiac potassium channel subtype is the preferable target for suppression of ventricular arrhythmias?

Prolongation of the cardiac action potential duration is the hallmark of Class III antiarrhythmic activity. Action potential duration prolongation may be achieved by several means: enhancement of inward current and, more commonly, blockade of one or more of the many outward currents that are carried by K+. However, it is far from clear whether blockade of one particular K+ channel is more efficacious than blockade of another. The objective of this review is to consider this question with particular reference to ischaemic heart disease, a condition for which effective prevention of ventricular arrhythmias continues to be sought.