title: Coexistence of congenital long QT syndrome and autonomic dysregulation in children.
abstract: Loss of consciousness (LOC) in long QT syndrome (LQTS) patients can be caused by torsade de pointes (TdP) or vasovagal syncope (VVS). On genetic testing and head-up tilt testing (HUTT), we diagnosed three young patients with both genotyped LQTS and autonomic dysregulation. According to grade of prolongation of QT interval and LOC status, syncope episodes in two patients were classified as due to VVS, while those of the other patient were due to TdP. We also diagnosed one patient with postural orthostatic tachycardia syndrome. Syncope in LQTS patients should not automatically be labeled TdP. If there is a possibility of VVS, HUTT should be performed, but careful observation is required because TdP cannot be completely ruled out.
authors.affiliation: Division of Cardiology, Kobe Children's Hospital, Kobe, Hyogo, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ogawa
authors.affiliation: Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Aiba
authors.affiliation: Division of Cardiology, Kobe Children's Hospital, Kobe, Hyogo, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Kamei
authors.affiliation: Division of Cardiology, Kobe Children's Hospital, Kobe, Hyogo, Japan.
authors.forename: Kenta
authors.initials: K
authors.lastname: Tominaga
authors.affiliation: Division of Cardiology, Kobe Children's Hospital, Kobe, Hyogo, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Fujita
authors.affiliation: Department of Preventive Medicine, National Cerebral and Cardiovascular Center, Tokyo, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Miyamoto
authors.affiliation: Division of Cardiology, Kobe Children's Hospital, Kobe, Hyogo, Japan.
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Division of Cardiology, Kobe Children's Hospital, Kobe, Hyogo, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Kido
mesh_terms: D002648:Child; D004562:Electrocardiography; D005260:Female; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D008133:Long QT Syndrome / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D018667:Tilt-Table Test; D014474:Unconsciousness / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology
keywords: head-up tilt testing; long QT syndrome; loss of consciousness; postural orthostatic tachycardia syndrome; vasovagal syncope