title: Abnormal repolarization dynamics in a patient with KCNE1(G38S) who presented with torsades de pointes.
abstract: Risk of G38S, major KCNE1 polymorphism [KCNE1(G38S)], for long QT syndrome (LQTS) remains unclear. A 72-year-old woman was admitted with recurrent torsades de pointes (TdP). She had remarkable QT prolongation (corrected QT interval 568 ms) under conditions of hypokalemia and hypomagnesemia. After correction of this electrolytic imbalance, TdP was suppressed and metoprolol was started. The QT-RR slope in 24-hour Holter electrocardiogram was steep and this enhanced bradycardia-dependent QT prolongation was similar to that in LQTS. She carried KCNE1(G38S). Patients with KCNE1(G38S) could have similar potential risk of ventricular arrhythmia as with LQTS. Analysis of QT-RR relationship could also evaluate the latent arrhythmogenicity of KCNE1(G38S).
authors.affiliation: Second Department of Internal Medicine, Graduate School of Medicine, University of Toyama, Toyama, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Yamaguchi
authors.affiliation: Clinical Research and Ethics Center, University of Toyama, Toyama, Japan. Electronic address: kmizu@med.u-toyama.ac.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Mizumaki
authors.affiliation: Legal Medicine, University of Toyama, Toyama, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Hata
authors.affiliation: Second Department of Internal Medicine, Graduate School of Medicine, University of Toyama, Toyama, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inoue
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D004562:Electrocardiography / Q000379:methods*; D015716:Electrocardiography, Ambulatory / Q000379:methods*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D024642:Potassium Channels, Voltage-Gated / Q000235:genetics*; D016171:Torsades de Pointes / Q000175:diagnosis* / Q000235:genetics*
chemical_list: C489622:KCNE1 protein, human; D024642:Potassium Channels, Voltage-Gated
keywords: KCNE1(G38S); QT-RR relation; hypokalemia; hypomagnesemia; long QT syndrome