Turk Kardiyol Dern Ars. 2007; 35(3): 187-194

Cardiac channelopathies and short QT syndromes

Nazmiye Çakmak, İzzet Erdinler, Ahmet Akyol
Dr. Siyami Ersek Thoracic And Cardiovascular Surgery Training And Research Center, Istanbul, Turkey

Disorders in the function of cardiac ion channels present as electrocardiographic abnormalities and arrhythmias and are described as cardiac channelopathies. Mutations in genes encoding specific ion channels have been shown to underlie these heritable arrhythmogenic disorders occurring in structurally normal hearts. These disorders include long QT syndromes, short QT syndromes (SQTS), Brugada syndrome, progressive cardiac conduction defect, idiopathic sick sinus syndrome, catecholaminergic polymorphic ventricular tachycardia, and familial atrial fibrillation. Short QT syndromes characterized by an abnormally short QT interval (<300 ms) and a propensity to atrial fibrillation and sudden cardiac death are new members of this group. Three distinct mutations in genes encoding cardiac potassium channels have been identified in this syndrome. Implantable cardioverter defibrillator (ICD) is presently the first choice of treatment. Because quinidine has been shown as the only drug that markedly prolongs the QT interval, this therapy can be considered in patients who refuse an ICD or in those who get frequent shocks from the ICD. This article aims to summarize cardiac channelopathies, with special reference to the diagnosis, pathophysiology, and treatment of SQTS

Keywords: Arrhythmia, electrocardiography, heart conduction system; ion channels; long QT syndrome/genetics/physiopathology; mutation; potassium channels/metabolism; sodium channels/metabolism; tachycardia, ventricular/physiopathology

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