Non-Invasive Electrophysiological Markers Associated With Long QT Syndrome

Abstract

Long QT syndrome (LQTS) is a life-threatening channelopathy, characterized by permanent or transient QT interval prolongation on the 12-lead electrocardiogram and syncope associated with malignant ventricular rhythm disturbances, particularly polymorphic ventricular tachycardia also known as torsade de pointes. Corrected QT (QTc) interval measurement remains the initial source of LQTS diagnosis in any patient, but the borderline QTc interval prolongation should induce further investigation. Genetic testing has the greatest value to provide definitive diagnosis in such situations, but it cant be applied to each patient routinely, putting aside that it can often be incomprehensive, costly or unavailable. The present review discusses the most promising non-invasive electrophysiological markers associated with Long QT syndrome, particularly in absence of visible QT interval prolongation and clinical manifestations.