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Pathophysiology of the long QT syndrome

Peter J Zimetbaum, MD
Section Editors
Samuel Lévy, MD
John K Triedman, MD
Samuel Asirvatham, MD
Deputy Editor
Brian C Downey, MD, FACC


The long QT syndrome (LQTS) is the phenotypic description of a group of disorders that are defined by two characteristics:

Prolongation of the QT interval

A characteristic arrhythmia, polymorphic ventricular tachycardia

The LQTS can be congenital, as an inherited disorder usually involving a mutation of an ion channel gene, or can be acquired as an adverse response to medication, metabolic abnormalities, or bradyarrhythmias (table 1) [1,2]. Torsades de pointes (TdP) or "twisting of points" is the specific type of polymorphic ventricular tachycardia (VT) associated with either form of the LQTS.

There are some pathophysiologic differences between the acquired and congenital forms of the LQTS.

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Literature review current through: Nov 2017. | This topic last updated: Feb 09, 2017.
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