The heartbeat is controlled by an electrical pulse that begins in pacemaker cells and spreads throughout the heart. This electrical pulse is controlled by the flow of potassium, sodium, and calcium ions across an electrical gradient in the heart cell membranes. Any disruption in this ion flow can lead to an abnormal heartbeat and potentially fatal arrhythmia (abnormal heart rhythm). Conditions that cause such disruptions are called cardiac ion channelopathies. The channelopathies include long QT syndrome (LQTS), Brugada syndrome (BrS), short QT syndrome (SQTS), and catecholaminergic polymorphic ventricular tachycardia (CPVT). Channelopathies can be diagnosed by a standard 12-lead electrocardiogram (ECG). Medical management of those with channelopathies depends on the observed phenotype/genotype and family history. Management includes restricted activity, drug therapy with beta blockers, avoidance of drugs that affect the corrected QT (QTc) interval, avoidance of hyperthermia, maintenance of electrolyte balance, and
implantation of a pacemaker or cardioverter defibrillator.