KCNH2 and torsades de pointes: Inhibition of the rapid component of the delayed rectifier potassium current, Ikr, encoded by KCNH2 is the commonest cause of drug induced long QT syndrome (LQTS) and torsades des pointes (TdP; ventricular tachycardia (Roden and Viswanathan, 2005; Wada et al., 2022).