Title : Cardiac channelopathies – Silent threat to sudden cardiac death
Abstract:
Sudden Death refers to the death of an individual within 24 hrs after being seen alive and in a normal state of health. The currently identified Channelopathies known to cause syncope and sudden death include Long QT Syndrome (LQTS), Short QT Syndrome (SQTS), Brugada Syndrome (BrS) and Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT). Cardiac channelopathies refer to a heterogeneous group of disorders caused by a malfunction of ion channels in the structurally normal heart. ION Channel is a cell membrane channel that is selectively permeable to certain ions (such as of calcium or sodium). Cardiac channelopathies constitute a heterogeneous group of inherited cardiac diseases caused by mutations in genes that encode for the ion channels expressed in the heart (involved in Na+ [INa], K+ [IK] and Ca2+ [ICa] currents) and/or the proteins that regulate their function. Cardiac Channelopathies are inherited cardiac disorders associated with potentially life-threatening ventricular arrhythmias.
They are caused by genetic mutations of ion channels that alter the cardiac cell membrane potential and intracellular hemostasis. over 17 genes have been implicated in the pathogenesis of LQTS, the majority of mutations perturb the critical ion channel pore-forming α-subunits encoded by 3 genes: The KCNQ1-encoded Kv7.1 potassium channel (type 1 long QT syndrome [LQT1]), the KCNH2-encoded Kv11.1 potassium channel (LQT2), and the SCN5A-encoded Nav1.5 sodium channel (LQT3). ICD: An implantable cardioverter-defibrillator (ICD) is a small battery-powered device placed in the chest. It detects and stops irregular heartbeats, also called arrhythmias. An ICD continuously checks the heartbeat. It delivers electric shocks, when needed, to restore a regular heart rhythm.
Conclusion: The primary challenges to SCD prevention are early identification of individuals at risk and clinical measures in asymptomatic individuals carrying a mutation, since the first manifestation of the disease can be SCD itself. In the future, comprehensive genotype-phenotype studies in large cohorts of families should be performed in order to clarify the genetic basis of SCD-related diseases as well as the adoption of personalized preventive therapies for the prevention of SCD.
