Monogenec Arrhythmic Syndromes: From Molecular and Genetic Aspects to Bedside

Abstract

The abrupt cessation of effective cardiac function that is generally due to heart rhythm disorders can cause sudden and unexpected death at any age and is referred to as a syndrome called sudden cardiac death (SCD). Annually, about 400,000 cases of SCD occur in the United States alone. Less than 5% of the resuscitation techniques are effective. The prevalence of SCD in a population rises with age according to the prevalence of coronary artery disease, which is the most common cause of sudden cardiac arrest. However, there is a peak in SCD incidence for the age below 5 years, which is equal to 17 cases per 100,000 of the population. This peak is due to congenital monogenic arrhythmic canalopathies. Despite their relative rarity, these cases are obviously the most tragic. The immediate causes, or mechanisms, of SCD are comprehensive. Generally, it is arrhythmic death due to ventricular tachyarrythmias - sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). Bradyarrhythmias and pulseless electrical activity account for no more than 40% of all registered cardiac arrests, and they are more often the outcome of the abovementioned arrhythmias. Our current understanding of the mechanisms responsible for SCD has emerged from decades of basic science investigation into the normal electrophysiology of the heart, the molecular physiology of cardiac ion channels, the fundamental cellular and tissue events associated with cardiac arrhythmias, and the molecular genetics of monogenic disorders of the heart rhythm (for example, the long QT syndrome). This review presents an overview of the molecular and genetic basis of SCD in the long QT syndrome, Brugada syndrome, short QT syndrome, catecholaminergic polymorphic ventricular tachycardia and idiopathic ventricular fibrillation, and arrhythmogenic right ventricular dysplasia, and sudden cardiac death prevention strategies by modern techniques (including implantable cardioverter-defibrillator).

Genome Editing and Cardiac Arrhythmias

“…A growing understanding of the genetics underlying cardiac arrhythmias has enabled new treatment possibilities including the use of cardiac genome editing [7]. Monogenetic diseases associated with cardiac arrhythmias include congenital long QT syndrome (LQTS), short QT interval syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia (CPVT), idiopathic ventricular fibrillation, Wolff-Parkinson-White syndrome, arrhythmogenic cardiomyopathy, and other cardiomyopathy syndromes associated with an increased risk of arrhythmias such as dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM) and hereditary transthyretin amyloidosis (ATTR-CM) [8]. Acquired arrhythmias such as atrial fibrillation or those associated with ischemic heart 2 of 13 disease are probably harder to treat using genome editing, although targeting a gene that is a master regulator in the pathogenesis might be feasible.…”