Linear ablation of postinfarction ventricular tachycardia substrate duringsinus rhythm

Objective. Radiofrequency ablation of ventricular tachycardia requires good tachycardia tolerance during mapping and entrainment, and this limits its application. We present our initial experience with ventricular tachycardia ablation during sinus rhythm in 7 patients with previous inferior myocardi al infarction. Methods. Seven men, 56-70 years old (mean +/- SD, 65 +/- 4,5) were included in the study. Ventricular tachycardia was unstable in 6 and in 1 it was in duced non-sustained. The scar was localized by recording low-voltage, fragm ented electrograms (< 2 mV). Ventricular tachycardia <<exit>> was localized by pace-mapping in sinus rhythm. Radiofrequency lines were made radially, point by point, from normal to scarred tissue. One of the lines crossed the exit area. The objective was to achieve non-inducibility. Results. Sustained clinical ventricular tachycardia was induced in 6 and no n-sustained in 1. Two-four lines were performed per patient with 11-28 (21 +/- 5.4) radio frequency applications. The procedure duration was of 130-28 0 min (230 +/- 61) and being 49-75 min (63 +/- 7.9) for fluoroscopy. There were no complications. Clinical ventricular tachycardia became non-inducibl e in 6, although in 4 a rapid (cycle less than or equal to 250 ms), non-cli nical ventricular tachycardia remained inducible. Defibrillators were impla nted in the patient remaining inducible for clinical ventricular tachycardi a and another with > 60 tachycardia episodes the previous week. During 3-22 months (13.8 +/- 5.9) of follow-up, 1 patient died of heart failure at 20 months and another received 3 defibrillator shocks for VT at 13 months. The re were no other episodes of ventricular tachycardia, syncope or sudden dea th. Conclusions. This preliminary experience suggests that radiofrequency ablat ion of post-infarction ventricular tachycardia substrate is possible during sinus rhythm, suggesting that radiofrequency ablation may be applicable in a large proportion of patients with post-infarction sustained ventricular tachycardia.