Blockade of human ether-a-go-go (hERG) channels and the subsequent inhibition of the rapidly activating delayed rectifier potassium current (IKr) is responsible for more than 95% of acquired or drug-induced Long QT syndromes and led to withdrawal of multiple drugs including terfenadine (Seldane) [36]. This evidence concerns the gene KCNH2 and Prolonged QT interval.