Substrate ablation for ventricular tachycardia in structural heart disease

Ventricular arrhythmias are a recurrent cause of mortality in patients with ischemic cardiomyopathy and non-ischemic cardiomyopathy. Scar-related reentry represents the most common arrhythmia substrate in patients with recurrent episodes of sustained ventricular tachycardia (VT). This chapter describes the existing evidence from different approaches and endpoints for substrate-based ablation of VT. To explore the hypothesis of superiority among substrate-based ablation compared to standard ablation of VT, the authors implemented an exploratory pooled analysis of studies comparing substrate-based versus standard ablation of VT in patients with structural heart disease. The detected improved arrhythmia-free survival goes along with the available evidence, but also provides novel evidence suggesting a mortality benefit in patients undergoing substrate-based ablation. Further studies, particularly randomized trials, are required to corroborate these interpretations. The chapter focuses on the specific strategies available for substrate-based ablation of VT. The substrate-based strategies include targeting late potentials, local abnormal ventricular activities, scar dechanneling, core isolation, and homogenization of the scar.