title: Genotype-specific risk stratification and management of patients with long QT syndrome.
abstract: Long QT syndrome (LQTS) is an inherited disorder associated with life-threatening ventricular arrhythmias. An understanding of the relationship between the genotype and phenotype characteristics of LQTS can lead to improved risk stratification and management of this hereditary arrhythmogenic disorder. Risk stratification in LQTS relies on combined assessment of clinical, electrocardiographic, and mutations-specific factors. Studies have shown that there are genotype-specific risk factors for arrhythmic events including age, gender, resting heart rate, QT corrected for heart rate, prior syncope, the postpartum period, menopause, mutation location, type of mutation, the biophysical function of the mutation, and response to beta-blockers. Importantly, genotype-specific therapeutic options have been suggested. Lifestyle changes are recommended according to the prevalent trigger for cardiac events. Beta-blockers confer greater benefit among patients with LQT1 with the greatest benefit among those with cytoplasmic loops mutations; specific beta-blocker agents may provide greater protection than other agents in specific LQTS genotypes. Potassium supplementation and sex hormone-based therapy may protect patients with LQT2. Sodium channel blockers such as mexiletine, flecainide, and ranolazine could be treatment options in LQT3.
authors.affiliation: Cardiology Department, Rabin Medical Center, Petah Tikva, and Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel; Cardiology Division, University of Rochester Medical Center, Rochester, NY.
authors.forename: Alon
authors.initials: A
authors.lastname: Barsheshet
authors.forename: Olena
authors.initials: O
authors.lastname: Dotsenko
authors.forename: Ilan
authors.initials: I
authors.lastname: Goldenberg
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D017147:Defibrillators, Implantable; D004562:Electrocardiography / Q000379:methods; D005260:Female; D005838:Genotype; D012739:Gonadal Steroid Hormones / Q000627:therapeutic use; D006339:Heart Rate; D006801:Humans; D008019:Life Style; D008133:Long QT Syndrome / Q000235:genetics* / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D011374:Progesterone / Q000627:therapeutic use; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D026941:Sodium Channel Blockers / Q000627:therapeutic use
chemical_list: D000319:Adrenergic beta-Antagonists; D012739:Gonadal Steroid Hormones; D026941:Sodium Channel Blockers; D011374:Progesterone
keywords: cardiac arrest/sudden death; long QT syndrome