Ablation of ventricular arrhythmic substrate: When the whole is more than the sum of its parts

Ablation of ventricular tachycardia (VT) is just one example in interventional electrophysiology in which treatment has shifted from focal ablation of the tachycardia exit point or circuit to wider ablation of the arrhythmic substrate which underlies the origin of the arrhythmia.Other examples of substrate ablation are known.I am specifically referring to the ablation of atrial fibrillation or atypical atrial flutter.Haissaguerre and colleagues began by ablating arrhythmogenic foci within the pulmonary veins, but, given the increased risk of complications associated with this strategy (such as pulmonary vein stenosis), they moved from this approach to the segmental isolation of the pulmonary veins.This subsequently gave rise to antral ablation, which eliminates an important substrate that can trigger and allow the perpetuation of atrial fibrillation. 1---3 In a similar fashion, ablation of the VT substrate destroys tissue that may be responsible for the appearance of potentially fatal arrhythmias in patients with significant left ventricular systolic dysfunction who do not tolerate the induction of such arrhythmias in the electrophysiology laboratory.