Effects on Repolarization Using Dynamic QT Interval Monitoring in Long-QT Patients Following Left Cardiac Sympathetic Denervation

Dynamic QT Interval Monitoring Post-LCSD BackgroundVideoscopic 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. MethodsWe 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. ResultsSeventy-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. ConclusionsAlthough 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.