Abstract 17344: The Efficacy of Catheter Ablation of Chatechomalinergic Polymorphic Ventricular Tachycardia with RyR2 Mutations
Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal arrhythmia characterized by bidirectional or polymorphic ventricular tachycardia (VT) leading to ventricular fibrillation (VF) and sudden cardiac death (SCD) with exercise or emotionally exciting situation. The generally accepted therapy for CPVT has been β-blockers. The implantable cardioverter-defibrillator (ICD) is considered to be the definitive therapy for the prevention of SCD; however, failure to prevent SCD has been reported in several cases with ICD, because ICD shock delivery might lead to catecholamine release, resulting in an electric storm. So, certain strategy to prevent SCD in CPVT has not been established. Therefore, we investigated the efficacy of catheter ablation for CPVT with mutation in the ryanodine receptor gene (RyR2).
Methods and results: There were 5 patients of CPVT with RyR2 mutation, who had experienced syncope episodes and/or cardiopulmonary arrest. Either bidirectional VT, Polymorphic VT and VF had been detected clinically, and had induced with electrophysiological study in all patients. The number of origins of bidirectional VT triggering VF were 11, including left bundle anterior branch area (n=3, 27%), left bundle posterior branch area (n=2, 18%), left ventricular outflow tract (n=3, 27%), right ventricular outflow tract (n=2, 18%) and other (n=1, 9%). Catheter ablations for all these origins were attempted resulting in non-inducibility of each ventricular arrhythmia in acute phase. With follow up period of 2.0±2.5 years, 4 patients of study subjects (80%) had not experienced any episode of syncope, PVT or VF except 1 patient who had non-sustained VF at the time of East Japan Earthquake.
Conclusion: These results suggested that catheter ablation for bidirectional VT’s triggering into VF is effective to prevent lethal ventricular arrhythmias in CPVT. The effect of catheter ablation for the substrate of genetic mutation related arrhythmias has not been established; however, catheter ablation could become one of the adjunctive therapies to avoid syncope, ICD shock deliver and SCD in patients with CPVT.
- © 2012 by American Heart Association, Inc.