SCN5A and polymorphic ventricular tachycardia: Examples of genetic cardiac disorders include congenital ectopic Purkinje-related premature contractions (MEPPC) and exercise induced polymorphic ventricular tachycardia (EPVT) which have been linked to the presence of the Nav1.5-p.R222Q and Nav1.5-p.I141V mutations [2–4].