الفهرس 
Ventricular Tachycardia: An OverviewOnly 14 pages are availabe for public view
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Abstract
Over the last few decades, catheter ablation of scar-related ventricular tachycardia (VT) has witnessed remarkable evolution and has gained much credit as a cornerstone in VT management, as per the 2022 ESC guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death.
The vast majority of scar-related ventricular tachycardias pose significant hemodynamic burden on patients presenting for catheter ablation of VT. This limits the role of activation and entrainment mapping for identification of ablation targets, given the necessity of induction of sustained VT. Moreover, the critical isthmus of VT is often difficult to identify, a single patient may have multiple scars and a single scar may house multiple reentrant circuits into the bargain. Substrate mapping has emerged as a feasible strategy to overcome such challenges, by identifying and targeting low voltage areas as well as regions with split, fractionated or late local potentials during intrinsic rhythm.
Notably, substrate-based strategies entail extensive ablation of abnormal potentials, although a substantial number of these may not be incorporated in reentry circuits. Further, it has been demonstrated that abnormal potentials may be buried within the QRS complex in sinus rhythm and manifest only with premature stimulation when tissue conduction properties are at stake. This led to the hypothesis that dynamic functional substrate mapping during ventricular extrastimulation might permit better identification of ablation targets with limited number of ablation lesions.
Several functional substrate mapping approaches have been proposed, including Decrement-evoked potential (DEEP) mapping, evoked delayed potential (EDP) mapping, hidden slow conduction (HSC) mapping, isochronal late activation mapping (ILAM), sense protocol (SP) mapping and paced electrogram feature analysis (PEFA). Despite proving feasibility in the clinical setting, none of these strategies have been compared to fixed-substrate mapping strategies as regards short and long term outcomes.