Changing the Way We “See” Scar: How Multimodality Imaging Fits in the Electrophysiology Laboratory

Substrate characterization is the mainstay of ablation for ventricular tachycardia (VT). Although the use of electroanatomic voltage mapping (EAVM) in the electrophysiology (EP) laboratory has enabled real-time approximation of myocardial scar, it has limitations. This is related to the subjective and tedious nature of voltage mapping and the challenges of defining the transmurality of scar. Various noninvasive methods of scar assessment have emerged, with magnetic resonance imaging (MRI) being the most accurate. Integrated MRI and electroanatomic voltage mapping studies demonstrate good correlation. Nonetheless, MRI has advantages. These include (1) preprocedure identification of epicardial and intramural scar, (2) assessment of ablative lesion formation after unsuccessful ablations, (3) identification of heterogeneous regions of scar, where critical conducting channels are likely to occur, and (4) predictive value in the assessment of sudden cardiac death (SCD). Integration of scar imaging in ventricular tachycardia ablation and risk stratification has great potential to advance the practice of arrhythmia management.