KCNH2 and ventricular fibrillation: Zhan et al. (2021) observed that the QT/QTc interval and incidence of ventricular fibrillation (VF) in guinea pig hearts were prolonged and elevated following a two-week treatment with Rutaecarpine (Rut), an extract of Evodia officinarum. Subsequent research revealed that Rut lowered PI3K/Akt pathway-mediated threonine (Thr)/tyrosine (Tyr) phosphorylation of Sp1, reducing hERG protein expression and inhibiting the hERG current (IhERG), thereby increasing the risk of VA and sudden death (Zhan et al., 2021).