Abstract 14219: Clinical and Electrocardiographic Characteristics in Relation to Ryanodine Receptor (RyR2) Gene Mutations in Patients with Catecholaminergic Polymorphic Ventricular Tachycardia Multi Center Study
Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare arrhythmogenic disorder characterized by exercise or emotional-induced polymorphic ventricular tachycardia, syncope, or sudden death. Two genetic variants of CPVT have been identified and cardiac ryanodine receptor (RyR2) mutations, transmitted as autosomal dominant traits, were found in 40-70% of probands with CPVT. The aim of this study was to assess the clinical features and prognosis of patients with CPVT.
Methods: Eighteen patients (pts) with CPVT (13 males, 8-42, 25.6±15.1 years) in whom ventricular fibrillation (VF) or bidirectional/polymorphic ventricular tachycardia (VT) was documented during physical or emotional stress and 25 family members from 9 families with RyR2 mutations were studied. The clinical characteristics and prognosis were compared between the RyR2 positive group probands and RyR2 negative group probands. To assess the oral medication therapy, exercise stress testing and Holter ECGs were performed after initiation of the therapy.
Results: RyR2 mutations were identified in 11 probands (61%) and 5 family members. Among the 11 mutations identified, 5 mutations have previously been reported and 6 mutations were de novo mutations. The CPVT probands with RyR2 mutations had their first symptom at a younger age than the probands without RyR2 mutations (9.6±6.7 years vs. 22.8±16.3 years p=0.020). Even under appropriate medical therapy with beta-blockers, calcium channel blockers and flecainide, 91% of the patients with RyR2 positive CPVT developed ventricular arrhythmias during exercise. Under appropriate medication therapy, all cardiac events occurred in patients younger than 15 years old.
Conclusions: CPVT probands with RyR2 mutations experienced their first cardiac event at a younger age. Even under maximum tolerated dose of oral drug therapy, strict restriction of their exercise during a young age plays an important role in preventing sudden cardiac death in the patients with CPVT.
- © 2011 by American Heart Association, Inc.