Sympathetic Denervation for Catecholaminergic Polymorphic Ventricular Tachycardia | Journal Scan

Study Questions:

What is the role of left cardiac sympathetic denervation (LCSD) for patients with refractory catecholaminergic polymorphic ventricular tachycardia (CPVT)?

Methods:

This multinational, observational study included 63 patients (recruited from 1988-2014) who underwent LCSD either as secondary (n = 54) or primary prevention (n = 9) of arrhythmic syncope, aborted cardiac arrest, or implantable cardioverter-defibrillator (ICD) shocks, i.e., major cardiac events (MCEs). The median age of onset of symptoms was 9 years. Optimal medical therapy consisted of maximally tolerated beta-blocker medications and/or flecainide.

Results:

Genotyping was available in 50 patients: mutations in the ryanodine receptor (RYR2) in 43, and calsequestrin (CASQ2) gene in 5 patients. Almost all patients were prescribed beta-blockers. Overall, the proportion of patients with MCEs decreased from 86% to 21% following LCSD (p < 0.001). Over a median follow-up of 39 months following LCSD, the prevalence of symptomatic patients decreased from 100% to 32%, and the mean annual event rate decreased by 92% per patient. Among the 37 patients (59%) who had received an ICD, there was a significant decrease in the rate of appropriate ICD discharges. Patients with incomplete denervation (7%) were more likely to experience MCEs.

Conclusions:

LCSD seems to be a potent antiarrhythmic intervention in patients with refractory CPVT.

Perspective:

CPVT is a potentially lethal genetic disorder that is notable for development of ventricular arrhythmias in the setting of high sympathetic tone, such as exercise. Mutations in RYR2 or CASQ2 alter calcium hemostasis leading to ventricular arrhythmias. First-line treatment consists of beta-blockers, which are effective in most patients. Patients with refractory symptoms are often treated with an ICD. However, device therapy may be ineffective, and is often associated with adverse events, especially in young patients. LCSD seems to be quite effective even in patients who are highly symptomatic despite medical therapy. The authors’ recommendation that patients with syncope despite medical therapy be first referred for LCSD as opposed to an ICD seems reasonable.

Clinical Topics: Arrhythmias and Clinical EP, Dyslipidemia, Prevention, Implantable Devices, EP Basic Science, Genetic Arrhythmic Conditions, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Lipid Metabolism

Keywords: Adrenergic beta-Antagonists, Anti-Arrhythmia Agents, Arrhythmias, Cardiac, Calsequestrin, Defibrillators, Implantable, Flecainide, Follow-Up Studies, Genotype, Heart Arrest, Hemostasis, Mutation, Prevalence, Primary Prevention, Ryanodine Receptor Calcium Release Channel, Secondary Prevention, Sympathectomy, Sympathetic Nervous System, Syncope, Tachycardia, Ventricular


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