SCN5A and atrial fibrillation: In fact, variants in the SCN5A gene have been described as causative for a number of other cardiac pathologies, such as ARVC/D, atrial standstill, atrial fibrillation, left ventricular non-compaction, dilated cardiomyopathy, LQTS, sick sinus syndrome, idiopathic ventricular fibrillation, and heart block (200, 201).