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Clinical features of congenital long QT syndrome

Authors
Stephen P Seslar, MD, PhD
Peter J Zimetbaum, MD
Charles I Berul, MD
Section Editors
John K Triedman, MD
Samuel Lévy, MD
Samuel Asirvatham, MD
Deputy Editor
Brian C Downey, MD, FACC

INTRODUCTION

The long QT syndrome (LQTS) is a disorder of myocardial repolarization characterized by a prolonged QT interval on the electrocardiogram (ECG) (waveform 1) and an increased risk of sudden cardiac death [1-3]. This syndrome is associated with an increased risk of a characteristic life-threatening polymorphic ventricular tachycardia known as torsades de pointes or "twisting of the points" (waveform 2A-B) [4,5]. The primary symptoms in patients with LQTS include palpitations, syncope, seizures, and cardiac arrest.

The long QT syndrome may be congenital or acquired. While mutations in numerous genes have been identified in patients with congenital LQTS (table 1), two clinical phenotypes have been described that differ in the type of inheritance and the presence or absence of sensorineural hearing loss [6]:

The more common autosomal dominant form, the Romano-Ward syndrome, has a purely cardiac phenotype. (See "Genetics of congenital and acquired long QT syndrome".)

The autosomal recessive form, the Jervell and Lange-Nielsen syndrome, is associated with LQTS and sensorineural deafness, and a more malignant clinical course [7]. (See 'Congenital sensorineural deafness' below.)

The epidemiology, clinical features, and conditions that are associated with congenital LQTS will be reviewed here. The diagnosis and management of congenital LQTS in children and adults and the clinical features of acquired LQTS are discussed separately. (See "Diagnosis of congenital long QT syndrome" and "Prognosis and management of congenital long QT syndrome" and "Acquired long QT syndrome".)

                        

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Literature review current through: Nov 2016. | This topic last updated: Thu Dec 04 00:00:00 GMT 2014.
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