KCNN4 and catecholaminergic polymorphic ventricular tachycardia: Since CPVT patients exhibit pacemaker dysfunction and CPVT mouse models display defects in SAN automaticity (Leenhardt et al, 1995; Postma et al, 2005; Katz et al, 2010; Neco et al, 2012; Faggioni et al, 2014; Glukhov et al, 2015), we explored whether SK4 channels are expressed in adult SAN and play a role in CPVT.