KCNH2 and Arrhythmia: This study builds on previous in silico work which has focused on QT interval shortening and arrhythmia substrates in the setting of SQT1 (Zhang and Hancox, 2004; Weiss et al., 2005; Adeniran et al., 2011), by using biophysically-detailed computational models to investigate the mode of action of two pharmacological agents which have demonstrated clinical effectiveness in partially reversing the SQT1 phenotype (Gaita et al., 2004; Wolpert et al., 2005; Schimpf et al., 2007; Giustetto et al., 2011).