Sympathectomy for CPVT Patients: Should We Have the Nerve?
Since the early descriptions almost four decades ago1, 2, there has been considerable expansion in the knowledge base for catecholaminergic polymorphic ventricular tachycardia (CPVT), with identification of underlying genetic mutations3, 4 and a better understanding of mechanisms leading to ventricular arrhythmias5, 6. However, as a malignant entity predisposing mostly young, apparently healthy individuals to sudden cardiac arrest (SCA), CPVT continues to pose a management challenge to the clinical cardiologist, often compounded by emotionally fraught situations. Risk stratification for CPVT remains problematic, particularly since long-term follow-up data in adequate numbers of patients is hard to obtain in this rare entity; yet clinical experience suggests fairly high event rates in diagnosed subjects7. The therapeutic approach to CPVT relies mainly on countering sympathetic stimulation as the key trigger of arrhythmia in this syndrome. Beta blockers have conventionally been the cornerstone of management with sizeable reductions in arrhythmia burden; unfortunately breakthrough events despite beta blocker therapy are not uncommon8. Side effects such as lethargy related to beta-blockade also result in non-compliance in this young population9. Calcium channel blockers such as verapamil have limited efficacy10 and the class Ic agent flecainide has shown some promise11 though long-term data are lacking. At the present time, implantable cardioverter defibrillators (ICDs) are advocated for those with sustained VT/syncope or aborted cardiac arrest despite beta blockers12. However, concerns have been raised about the possibility of VT storm and death due to the sympathetic surge following ICD shocks13 as well as the relatively high rate of inappropriate shocks and device complications in these young patients14. Left cardiac sympathetic denervation (LCSD) has emerged as an alternative approach to sympathetic blockade and has been effectively used in other inherited arrhythmia syndromes such as the long QT syndrome15. While scattered reports of the success of LCSD in abolishing arrhythmia in CPVT exist16, 17, recommendation for its adoption as standard therapy has been hampered by lack of data on long-term efficacy.
- Received May 20, 2015.
- Accepted May 21, 2015.