title: Effects on repolarization using dynamic QT interval monitoring in long-QT patients following left cardiac sympathetic denervation.
abstract: BACKGROUND
  Videoscopic left cardiac sympathetic denervation (LCSD) is an adjunct therapy for reduction of arrhythmia-induced events in patients with long-QT syndrome (LQTS). LCSD reduces LQTS-triggered breakthrough cardiac events. The temporal effects of QTc changes post-LCSD have not been studied.
  
  
  METHODS
  We utilized continuous QTc monitoring on 72 patients with LQTS. We evaluated acute and long-term QTc changes in comparison to 12-lead ECG-derived QTc values prior to surgery, 24 hours postsurgery, and at follow up ≥3 months.
  
  
  RESULTS
  Seventy-two patients underwent LCSD at our institution (46% male, mean age at LCSD was 14 ± 10 years). The mean baseline, pre-LCSD QTc was 505 ± 56 ms, which had decreased significantly at ≥3 months post-LCSD to 491 ± 40 ms (P = 0.001). QTc monitoring revealed that the majority of the cohort (53/72; 74%) had a transient increase >30 ms in QTc from baseline, with an average maximum increase of 72 ± 30 ms. Resolution within 10 ms of baseline or less occurred in 57% (30/53) at 24 hours post-LCSD.
  
  
  CONCLUSIONS
  Although LQTS patients may have a paradoxically increased QTc post-LCSD, the effects are transient in most patients. Importantly, no patients experienced any arrhythmias in the postoperative setting related to this transient rise in QTc.
authors.affiliation: Division of Cardiovascular Diseases, Rochester, Minnesota, USA.
authors.forename: Christopher V
authors.initials: CV
authors.lastname: Desimone
authors.affiliation: Department of Pediatric and Adolescent Medicine, Mayo Clinic Rochester, Minnesota, USA.
authors.forename: J Martijn
authors.initials: JM
authors.lastname: Bos
authors.affiliation: Department of Nursing, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Katy M
authors.initials: KM
authors.lastname: Bos
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Jackson J
authors.initials: JJ
authors.lastname: Liang
authors.affiliation: Mayo Medical School, Rochester, Minnesota, USA.
authors.forename: Nikhil A
authors.initials: NA
authors.lastname: Patel
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Jacksonville, Florida, USA.
authors.forename: David O
authors.initials: DO
authors.lastname: Hodge
authors.affiliation: Division of Cardiovascular Diseases, Rochester, Minnesota, USA.
authors.forename: Amit
authors.initials: A
authors.lastname: Noheria
authors.affiliation: Division of Cardiovascular Diseases, Rochester, Minnesota, USA.|Department of Pediatric and Adolescent Medicine, Mayo Clinic Rochester, Minnesota, USA.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Asirvatham
authors.affiliation: Division of Cardiovascular Diseases, Rochester, Minnesota, USA.|Department of Pediatric and Adolescent Medicine, Mayo Clinic Rochester, Minnesota, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Ackerman
mesh_terms: D000200:Action Potentials; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015716:Electrocardiography, Ambulatory; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D008133:Long QT Syndrome / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D012984:Software; D013562:Sympathectomy / Q000009:adverse effects / Q000379:methods*; D020775:Thoracic Surgery, Video-Assisted / Q000009:adverse effects / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
keywords: ICD; QTc; arrhythmia; left cardiac sympathetic denervation; long-QT syndrome; sudden cardiac death; syncope