Effects on repolarization using dynamic QT interval monitoring in long-QT patients following left cardiac sympathetic denervation

J Cardiovasc Electrophysiol. 2015 Apr;26(4):434-439. doi: 10.1111/jce.12609. Epub 2015 Feb 8.

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.

Keywords: ICD; QTc; arrhythmia; left cardiac sympathetic denervation; long-QT syndrome; sudden cardiac death; syncope.

MeSH terms

  • Action Potentials
  • Adolescent
  • Child
  • Child, Preschool
  • Electrocardiography, Ambulatory*
  • Female
  • Heart / innervation*
  • Heart Rate*
  • Humans
  • Long QT Syndrome / diagnosis
  • Long QT Syndrome / physiopathology
  • Long QT Syndrome / surgery*
  • Male
  • Predictive Value of Tests
  • Retrospective Studies
  • Signal Processing, Computer-Assisted
  • Software
  • Sympathectomy / adverse effects
  • Sympathectomy / methods*
  • Thoracic Surgery, Video-Assisted / adverse effects
  • Thoracic Surgery, Video-Assisted / methods*
  • Time Factors
  • Treatment Outcome
  • Young Adult