Mutations of Voltage-Gated Ionic Channels and Risk of Severe Cardiac Arrhythmias

Background: Arrhythmias as important malfunctions of heart are known as abnormal rhythm of heart. Several causes can make arrhythmias and most of them are related to generation and/or conduction of action potential in heart. Action potential in myocytes results from the sequential opening and closing of ion channel proteins that span the plasma membrane of individual myocytes. Action potential's conduction through the heart is depended on electrical coupling between myocytes, which is mediated by gap junctions. Generation and conduction of action potentials are related to perfect action of ionic channels in heart. Objectives: This novel review comprehensively addressed the ionic mechanisms of the arrhythmogenic mutations in cardiac voltage-gated ionic channels including: CACNA1C, CACNA1D, KCNA5, KCND2, KCND3, KCNE1, KCNE2, KCNE5, KCNH2, KCNJ2, KCNJ5, KCNQ1, SCN4A, SCN5A, SCN1B, SCN2B, SCN3B and SCN4B. Methods: Current study, for the first time, review and discuses about relation between cardiac arrhythmias and whole of important voltage gated ionic channels from different families, altogether and at the same time. Results: This review clears that mutations in voltage-gated ionic channels play important roles in generation of severe cardiac arrhythmias, and among them it is looked that mutations in voltage-gated potassium channels are more important. Conclusions: Most of induced arrhythmias due to voltage-gated ionic channels mutations result in action potentials prolongation and long QT syndromes. Study on ionic channel regulators can be considered as a subject for future research.