An inherited condition involving mutations that affect ion channels important in myocardial repolarization.
May also be acquired secondary to drugs, electrolyte imbalances, or bradyarrhythmias.
Twelve-lead ECG commonly shows a prolonged QT interval.
Sufferers are at increased risk of syncope, ventricular arrhythmias (including torsades de pointes), and sudden cardiac death.
Primary treatment involves beta-blockers and, in selected cases, implantation of a cardioverter-defibrillator, as well as avoidance of competitive sports and QT-prolonging drugs.
Long QT syndrome (LQTS) is a genetic or acquired condition characterized by a prolonged QT interval on the surface ECG and is associated with a high risk of sudden cardiac death due to ventricular tachyarrhythmias. Mutations within 13 identified genes result in a variety of channelopathies affecting myocardial repolarization, thus prolonging the QT interval.
History and exam
- hx of known gene mutation
- use of drugs or circumstances known to increase the QT interval
- syncope during heightened adrenergic tones
- syncope during arousal or surprise
- arrhythmic symptoms post partum
- syncope at rest and during bradycardia
- cardiac syncope
- periodic paralysis
- dysmorphic features
- sensorineural deafness
Associate Professor of Medicine
University of Rochester Medical Center
MKA declares that he has no competing interests.
Professor of Medicine
Duke University Medical Center
Duke Clinical Research Institute
JPD is a consultant for the American College of Cardiology, ARCA Biopharma, Biosense Webster, Biotronik, Boston Scientific, Cardiofocus, Gilead Sciences Inc., Medtronic Inc., NIH-NHLBi, Northwestern University, Orexigen Therapeutics Inc., St. Jude, and Vytronus.
Director of Cardiac Hospitalization
Department of Cardiology
Tel Aviv Medical Center
SV declares that he has no competing interests.
Heart and Vascular Center
Case Western Reserve University
ESK declares that she has no competing interests.
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