Standard Ablation Versus Magnetic Resonance Imaging-Guided Ablation in the Treatment of Ventricular Tachycardia

Radiofrequency ablation is an effective treatment strategy for ischemic and nonischemic cardiomyopathy-related ventricular tachycardia (VT). The role of substrate-guided ablation, performed using electrogram characteristics (low amplitude, fractionated or isolated potentials) as scar surrogates, is expanding because of frequent hemodynamic instability during entrainment mapping of scarrelated VT. Late gadolinium-enhancement on cardiac magnetic resonance imaging (LGE-MRI) can accurately characterize the transmural extent, location, and configuration of ventricular scar.(1) Integration of LGE-MRI into electroanatomical mapping during VT ablation was shown, in preliminary studies, to be feasible and to provide accurate localization of VT substrate and reentry circuits. 2-4 However, studies to date examining the impact of MRI scar integration on procedural outcomes have lacked control groups, precluding any comparisons with standard practice. We performed a study to (1) demonstrate the feasibility in clinical practice of integrating MRI-derived scar for guidance of VT ablation; (2) report on the periprocedural performance of LGE-MRI in identifying the arrhythmogenic substrate; and (3) examine the impact of MRI-guided ablation on procedural length and acute and long-term outcomes.