Moir, Christopher

Introduction: Long QT Syndrome (LQTS) is a potentially lethal, but highly treatable cardiac channelopathy. Current treatment options include pharmacotherapy (mostly beta blockers), device therapy (mostly implantable cardioverter defibrillators (ICDs)), and/or left cardiac sympathetic denervation (LCSD) with the majority of patients requiring only beta blocker therapy. However, beta blockers are not without side effects and beta blocker intolerance can have a profoundly negative effect on a patient's quality of life. Heretofore, a prophylactic ICD has been utilized for the patient with LQTS who can not tolerate high dose beta blocker therapy. Here we examined the role of a prophylactic LCSD rather than an ICD for the LQTS patient with beta blocker intolerance. Methods: In this IRB-approved study, we retrospectively reviewed the electronic medical record for 58 patients (28 male (48%), mean age at diagnosis 9.6 ± 9 years (yrs), mean baseline QTc 524 ± 73 ms, 93% genotype positive) with LQTS who underwent LCSD at our institution from November 2005 through May 2011 (mean age at LCSD 14.0 ± 9.8 yrs). Results: Out of 58, 19 patients (33%; 15 female (79%) had LCSD as primary prevention because of beta blocker intolerance and were older at LQTS diagnosis (15.1 ± 8 vs 7.0 ± 9 yrs;.p=0.001), older at LCSD (20.5 ± 8 vs 10.9 ± 9 yrs; p<0.001), and had a shorter baseline QTc (493 ± 32 vs 539 ± 82 ms; p = 0.004) compared to the other 38 patients. Post-LCSD, 5/19 (26 %) had QTc-shortening of >30ms. With an average follow-up of 1.3 ± 0.8 yrs, none of these patients have experienced a post-LCSD cardiac event even though 7/19 (37%) had at least 1 LQTS-associated cardiac event. Qualitatively, there has been a dramatic improvement in quality of life following LCSD with subsequent decrease in beta blocker dose in 13 or discontinuation of beta blockers altogether in 5. Conclusions: Prophylactic LCSD may provide a beta blocker-reducing or even sparing strategy without increasing risk in carefully selected patients. However, LCSD should not be viewed as curative or an ICD-alternative for high-risk patients. Among appropriately selected patients who are failing to tolerate beta blocker therapy, LCSD may be an acceptable, quality of life improving alternative to an ICD and its associated comorbidities.

Background: Videoscopic left cardiac sympathetic denervation (LCSD) is an effective antifibrillatory, minimally invasive therapy for patients with potentially life-threatening arrhythmia syndromes like long QT syndrome (LQTS). Although initially used primarily for treatment intensification following documented LQTS-associated breakthrough cardiac events while on beta-blockers, LCSD as 1-time monotherapy for certain patients with LQTS requires further evaluation. We are presenting our early experience with LCSD monotherapy for carefully selected patients with LQTS. Methods: Among the 1400 patients evaluated and treated for LQTS, a retrospective review was performed on the 204 patients with LQTS who underwent LCSD at our institution since 2005 to identify the patients where the LCSD served as stand-alone, monotherapy. Clinical data on symptomatic status before diagnosis, clinical, and genetic diagnosis, and breakthrough cardiac events after diagnosis were analyzed to determine efficacy of LCSD monotherapy. Result: Overall, 64 of 204 patients (31%) were treated with LCSD alone (37 [58%] female, mean QTc 466±30 ms, 16 [25%] patients were symptomatic before diagnosis with a mean age at diagnosis 17.3±11.8 years, 5 had [8%] ≥1 breakthrough cardiac event after diagnosis, and mean age at LCSD was 21.1±11.4 years). The primary motivation for LCSD monotherapy was an unacceptable quality of life stemming from beta-blocker related side effects (ie, beta-blocker intolerance) in 56/64 patients (88%). The underlying LQTS genotype was LQT1 in 36 (56%) and LQT2 in 20 (31%). There were no significant LCSD-related surgical complications. With a mean follow-up of 2.7±2.4 years so far, only 3 patients have experienced a nonlethal, post-LCSD breakthrough cardiac event in 180 patient-years. Conclusions: LCSD may be a safe and effective stand-alone therapy for select patients who do not tolerate beta-blockers. However, LCSD is not curative and patient selection will be critical when potentially considering LCSD as monotherapy.