Feasibility of Targeting Catheter Ablation to the Markedly Low-Voltage Area Surrounding Infarct Scars in Patients With Post-Infarction Ventricular Tachycardia

摘要

Background In routine substrate mapping of the left ventricle, an abnormal area is defined as having an amplitude <1.5mV. However, that is usually too large for catheter ablation in post-infarction ventricular tachycardia (VT) and the use of strict voltage criteria may produce better outcomes.Methods and Results Twenty patients with post-infarction VT underwent substrate mapping using an elec-troanatomic mapping system. Strict voltage criteria were defined as: non-arrhythmogenic area, >0.6mV; low-voltage area (LVA), >0.1 to <0.6mV; scar, <0.1 mV. Radiofrequency applications targeted the LVA only, which was 48 +- 26cm~2, 55% smaller than that of the generally targeted area with an amplitude <1.5 mV. The prevalence of delayed electrograms (duration >150ms) was significantly higher in the LVAs than in the border areas with an amplitude of >0.6 to <= 1.5mV (33.2% vs 3.7%, p<0.001). With the exception of 2 instances of peri-mitral VT, all VT isthmuses resided within the LVA. During follow-up of 24 +- 13 months, 16 patients (80%) have been free of any VT episodes.Conclusions Catheter ablation targeting LVAs with an amplitude <0.6 mV appears to be useful for efficient and effective treatment of post-infarction VT.