Channelopathies and Heart Disease

Abstract

Channelopathies represent diseases caused by mutations in the genes encoding ion channels or associated proteins. With the advent of novel electrophysiology and molecular biology techniques, a wide variety of ion channels have been identifi ed in different regions of the working myocardium or conduction system, and their biophysical and pharmacological properties, as well as involvement in different pathophysiology processes, are thoroughly characterized. This wealth of knowledge offers a better understanding of the intricate chemical and electrical events underlying a large class of rare heart diseases, most of them associated with arrhythmias, and also reveals novel mechanisms in the most frequent cardiovascular diseases and their complications. Within the present chapter we tackled the challenging task of presenting a comprehensive review of this rapidly expanding domain, with the hope of rendering relevant information for specialists with an interest in this highly exciting fi eld of research.

Transcriptomic uniqueness and commonality of the ion channels and transporters in the four heart chambers

“…Kcnq1 encoding Kv7.1 or KvLQT1, the ion channel contributing the slow component of the cardiac delayed rectifier K + current I Ks , is also preferentially expressed in atria. This ion channel, activated by β-adrenergic stimulation, provides a "repolarization reserve" that is very useful during physical exercise 51 ; it is also the cause of the most widespread type of long QT syndrome, LQT-1 52,53 . Although evidenced in isolated human ventricular cardiomyocytes 54 , patch-clamp experiments on isolated mouse ventricular myocytes failed to identify a distinct I Ks 53,55 .…”