As far as channelopathies are concerned, the SCN5A gene encoding the α subunit of the cardiac voltage-gated sodium channel (Nav1.5) might harbor several mutations associated with arrhythmia vulnerability syndromes including the Brugada syndrome [12], sick sinus syndrome [13], the arrhythmogenic long QT syndrome [14] and susceptibility to ventricular fibrillation during myocardial infarction [15]. Here, SCN5A is linked to sick sinus syndrome.