Targeting Noninducible Clinical Ventricular Tachycardias in Patients With Prior Myocardial Infarctions Based on Stored Electrograms

Background: Ablation of postinfarction ventricular tachycardia (VT) has been shown to reduce VT recurrence and decrease mortality. However, VT recurrence can occur despite extensive ablation procedures. The lack of inducibility of clinical VTs during ablation procedures remains problematic and may be in part responsible for VT recurrences. In this prospective study, we targeted documented but noninducible clinical VTs based on stored implantable cardioverter-defibrillator (ICD) electrograms. Methods: Radiofrequency ablation was performed in a consecutive group of 66 postinfarction patients (mean age, 67.5 +/- 9.2 years; men, 61; mean left ventricular ejection fraction, 25.1 +/- 10.8%) in whom clinical VTs were not inducible during an ablation procedure. In the first 33 patients (control group), only inducible VTs were targeted, and in the second 33 patients, noninducible clinical VTs were also targeted by pace-mapping based on stored ICD-electrograms (ICD-electrogram-guided ablation group). Procedural and clinical outcomes were compared at 24 months post-ablation. Results: VT recurred in 5 patients (15%) in whom the ICD-electrogram-guided approach was performed and in 13 patients (39%) in the control group. Freedom from recurrent VT was higher (log-rank P=0.04) in the ICD-electrogram-guided group, but there was no difference in ventricular fibrillation or in total mortality between both groups. Conclusions: Ablation guided by pace-mapping of noninducible postinfarction clinical VTs based on ICD-electrograms is feasible and reduces the risk of recurrent VT.