Catheter Ablation of Ventricular Tachycardia in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

ABSTRACT

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is predominantly an inherited cardiomyopathy with typical histopathological characteristics of fibro-fatty infiltration mainly involving the right ventricular (RV) inflow tract, RV outflow tract, and RV apex in the majority of patients. The above pathologic evolution frequently brings patients with ARVD/C to medical attention owing to the manifestation of syncope, sudden cardiac death (SCD), ventricular arrhythmogenesis, or heart failure. To prevent future or recurrent SCD, an implantable cardiac defibrillator (ICD) is highly desirable in patients with ARVD/C who had experienced unexplained syncope, hemodynamically intolerable ventricular tachycardia (VT), ventricular fibrillation, and/or aborted SCD. Notably, the management of frequent ventricular tachyarrhythmias in ARVD/C is challenging, and the use of antiarrhythmic drugs could be unsatisfactory or limited by the unfavorable side effects. Therefore, radiofrequency catheter ablation (RFCA) has been implemented to treat the drug-refractory VT in ARVD/C for decades. However, the initial understanding of the link between fibro-fatty pathogenesis and ventricular arrhythmogenesis in ARVD/C is scarce, the efficacy and prognosis of endocardial RFCA alone were limited and disappointing. The electrophysiologists had broken through this frontier after better illustration of epicardial substrates and broadly application of epicardial approaches in ARVD/C. In recent works of literature, the application of epicardial ablation also successfully results in higher procedural success and decreases VT recurrences in patients with ARVD/C who are refractory to the endocardial approach during long-term follow-up. In this article, we review the important evolution on the delineation of arrhythmogenic substrates, ablation strategies, and ablation outcome of VT in patients with ARVD/C.