Demonstrating the deceleration zone associated with epicardial conduction using isochronal late activation mapping during right ventricular apex pacing

Substrate-based approaches for ventricular tachycardia (VT) ablation aim to ablate the channels that serve as the substrate for VT propagation without the requirement to map them during VT. Isochronal latest activation mapping (ILAM)1,2 is a method by which the chamber of interest is mapped using a consistent wavefront and is useful for detecting the VT’s critical zone. A previous study has shown that conduction-slowing areas such as deceleration zones (DZs) during sinus rhythm identified by ILAM are related to the exit site of the VT isthmus.