KCNH2 and torsades de pointes: Thus, while effective, the current paradigm may be inappropriately assigning TdP liability to some drugs, especially in the discovery realm, so work is ongoing to shift from one that strongly relies on QT interval prolongation (or is “hERG-centric”) to one where proarrhythmic risk would be primarily assessed using non-clinical in vitro human models based on solid mechanistic considerations of TdP proarrhythmia (2) in conjunction with the current in vivo QT conscious canine and other non-rodent models.