Impact of substrate-based ablation for ventricular tachycardia in patients with frequent appropriate implantable cardioverter-defibrillator therapy and dilated cardiomyopathy: Long-term experience with high-density mapping Mário Oliveira; Pedro Cunha; Bruno Valente; Guilherme Portugal; Ana Lousinha; Mariana Pereira; Manuel Braz; Ana Delgado; Rui C. Ferreira;