Elimination of Local Abnormal Ventricular Activities

Abstract

Background-Catheter ablation of ventricular tachycardia (VT) is effective and particularly useful in patients with frequent defibrillator interventions. Various substrate modification techniques have been described for unmappable or hemodynamically intolerable VT. Noninducibility is the most frequently used end point but is associated with significant limitations, so the optimal end point remains unclear. We hypothesized that elimination of local abnormal ventricular activities (LAVAs) during sinus rhythm or ventricular pacing would be a useful and effective end point for substrate-based VT ablation. As an adjunct to this strategy, we used a new high-density mapping catheter and frequently used epicardial mapping. Methods and Results-Seventy patients (age, 67Ϯ11 years; 7 female) with VT and structurally abnormal ventricle(s) were prospectively enrolled. Conventional mapping was performed in sinus rhythm in all, and a high-density Pentaray mapping catheter was used in the endocardium (nϭ35)

Correlation of Scar in Cardiac MRI and High‐Resolution Contact Mapping of Left Ventricle in a Chronic Infarct Model

“…ILPs, which represent delayed activation of surviving muscle bundles within scarred myocardium, are now considered the most suitable targets for ablation of critical isthmuses of the circuits for reentrant tachycardias 4, 6, 7, 9. In clinical practice, these low‐amplitude late potentials are sought in and around low‐voltage areas.…”

“…Substrate mapping to identify the abnormal low‐voltage areas and the critical components of possible VT circuits (surviving myocardial bundles) is an effective strategy and often the only method available. Although several approaches have been utilized for substrate mapping,3, 4, 5, 6 one of the simplest and most direct is to record the isolated late potentials (ILPs) generated by the late activation of the isolated myocardial bundles during sinus rhythm5, 7, 8, 9 or ventricular pacing. This approach has two limitations.…”

Atrial tachycardia related to local abnormal atrial activity

“…LAVA has been described as exhibiting sharp high‐frequency ventricular potentials, and the elimination of that LAVA is associated with a superior ventricular tachycardia (VT)‐free survival 1. The interval between the local systolic electrogram and LAATA increased (Figure 1A), and the delay was associated with the induction of the AT.…”

“…The focal AT origin is identified using a three‐dimensional electro‐anatomical mapping system. Substrate‐based ablation has been used for ventricular tachycardia, and late potentials (LPs) and local abnormal ventricular activity (LAVA) should be eliminated during those substrate‐based strategies 1, 2. However, LPs and local abnormal activity have not been described in the field of AT.…”

Catheter ablation of hemodynamically unstable ventricular tachycardia in ischemic cardiomyopathy using high‐resolution mapping

“…In consequence, a substrate‐based ablation was performed using an antegrade approach with a 7F, 3.5 mm irrigated‐tip catheter (Thermocool SF ® , Biosense Webster, Diamond Bar, CA) and up to 32 W 8. In total, 19 RF applications (total duration of 2694 sec) were performed targeting LAVAs and late potentials in the crucial scar areas that were detected by the activation and voltage map 9. The signals acquired with the ablation catheter showed high consistency compared to those acquired with the basket‐catheter.…”