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 post-surgery, and at follow up ≥3 months. Results 72 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.

ArrhythmoGenoPharmacoTherapy

“…The left cardiac sympathetic denervation was also proposed as a useful therapy for LQTS including CPVT (De Ferrari et al, 2015;Desimone et al, 2015;Sgro et al, 2019) in addition to the application of anti-arrhythmic agents and implantable cardioverter defibrillators. Thus, the combination of these interventions can significantly improve the final outcome of the clinical management of LQTS including CPVT in patients, and the prevention of sudden cardiac death.…”

Implantable cardioverter-defibrillator explantation for overdiagnosed or overtreated congenital long QT syndrome

“…3,7 In high-risk patients, however, more invasive measures, including left cardiac sympathetic denervation (LCSD) or an implantable cardioverter defibrillator (ICD), may be warranted. 8 Difficulties in making the LQTS diagnosis accompanied by the possible dire outcomes of a missed diagnosis sometimes lead to overdiagnosis of the disease and possibly overaggressive treatment, including overzealous implantation of an ICD. This decision also introduces the potential for device-related complications, including infection, malfunction, inappropriate shocks, and possible anxiety.…”

Effect of Left Cardiac Sympathetic Denervation on the Electromechanical Window in Patients with either Type 1 or Type 2 Long QT Syndrome: A Pilot Study

“…Our early results of this pilot study, noting a trend toward improvement and normalization of EMW in 10/13 (77%) post-LCSD LQTS patients, raises the possibility that denervation's protective effect may be conferred in part by restoring electromechanical order rather than attenuation of the QTc. 6,15 Congenital LQTS is a disease that manifests phenotypically with abnormal dispersion of electrical depolarization, as evidenced by QT prolongation on an ECG, and mechanical dispersion which has been well documented using M-mode techniques, strain imaging, as well as tissue Doppler evaluation. [16][17][18][19][20] Although electromechanical heterogeneity is present in healthy individuals, it is more significantly pronounced in patients with LQTS and likely underlies the torsadogenic propensity in this particular population.…”

“…5 Given the therapeutic and comorbidity gap between pharmacological and ICD therapy, there has been a renewed interest in LCSD, a minimally invasive procedure that reduces arrhythmia burden and attenuates corrected QT interval (QTc) in symptomatic patients. [6][7][8][9][10][11] Given the nature of the disease and possible occurrence of rare, but potentially lethal arrhythmias, clinicians must determine which patients necessitate more aggressive, and often invasive, therapeutic interventions based on perceived risk for future LQTS-triggered cardiac events. Risk assignment is usually based on a personal history of syncope, seizures, or sudden cardiac arrest, family history of LQTS or sudden cardiac arrest, as well as patient age, gender, genotype, and QTc on ECG.…”