KCNJ2 and atrial fibrillation: The electrophysiological changes of IK1 properties caused by the K346T mutation are very similar to those of the other KCNJ2 mutation found in SQT3S (i.e. D172N; 8) and atrial fibrillation (47), indicating that K346T likely contributes to arrhythmia generation by affecting the excitability of myocytes.