Cardiac channelopathies

Cardiac channelopathies

Electrical system of the heart operates on the electrical impulses generated by the specialized conducting system of the heart. These are controlled by pores in the cardiac cell membrane known as ion channels. The ion channels mediate the flow of potassium, sodium and calcium ions across the myocyte membrane and the sarcoplasmic reticulum. Cardiac channelopathies are primary electrical disorders of the heart which occur when the proteins forming the ion channels have a dysfunction, which could be either a loss of function or a gain of function.

The important cardiac channelopathies are the long QT syndromes, Brugada syndrome, catecholaminergic polymorphic ventricular tachycardia, short QT syndrome, familial atrial fibrillation and familial sick sinus syndrome. There is a lot of genetic heterogeneity within these syndromes and several types of each syndrome due to various genes have been described. At the same time, the identified genetic mutations do not account for all of the cases of these syndromes, meaning that many more genetic mutations are yet to be identified.