Cardiac channelopathies

Sudden cardiac death is one of the leading causes of death in the Western world. A significant proportion of sudden cardiac death (especially in the young) is caused by cardiac channelopathies. These are inherited disorders caused by DNA defects that alter the structure and function of cardiac ion channel and the electrical properties of the heart without affecting heart structure. These alterations predispose to the development of arrhythmias that can cause sudden death. In the last 20 years our understanding of these conditions has grown exponentially, mainly because of the huge advances in molecular biology and genetics. Close collaboration between the geneticist and the cardiologist is essential for the diagnoses and treatment of these disorders. In this chapter we review the most common cardiac channelopathies, including long QT syndrome, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, and short QT syndrome. We put particular emphasis on the role played by genetics in the diagnosis and treatment of these conditions.