Patients with Scar-Related Right Ventricular Tachycardia: Determinants of Long-Term Outcome

Introduction: Patients with established arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) based on task force (TF) criteria and ventricular tachycardia (VT) are at risk of VT recurrence and sudden death. Data on patients with VT due to right ventricular (RV) scar not fulfilling TF criteria are lacking. The purpose of this study was to assess the long-term arrhythmia recurrence rate and outcome in patients with scar-related right VT with and without a diagnosis of ARVC/D.
Methods: Sixty-four patients (age 43.5 ± 15 years, 49 males) presenting with nonischemic scar-related VT of RV origin were studied. Scar was identified by electroanatomical mapping, contrast echocardiography, and/or magnetic resonance imaging (MRI). Patients were evaluated and treated according to a standard institute protocol.
Results: Twenty-nine (45%) patients were diagnosed with ARVC/D according to TF criteria (TF+) and 35 (55%) with RV scar of undetermined origin (TF–) at the end of follow-up (64 ± 42 months). Patients were treated with antiarrhythmic drugs, radiofrequency catheter ablation, and/or implantable cardioverter-defibrillator (ICD) implantation. VT recurrence-free survival for TF+ and TF– was 76% versus 74% at 1 year and 45% versus 50% at 4 years (P = ns). Patients with fast index VT (cycle length CL]≤ 250 ms, n = 31) were more likely to experience a fast VT during follow-up than patients with a slow index VT (CL > 250 ms, n = 33) (61% vs 3%, P < 0.001).
Conclusions: Scar-related RV VTs have a high recurrence rate in TF+ and TF– patients. Patients presenting with a fast index VT are at high risk for fast VT recurrence and may benefit most from ICD therapy.