PREDICTORS FOR SUCCESSFUL ABLATION OF RIGHT-SIDED AND LEFT-SIDED IDIOPATHIC VENTRICULAR-TACHYCARDIA

This study reports on predictors for successful radiofrequency (RF) ab lation of idiopathic ventricular tachycardia (VT) in 48 patients-35 wi th right ventricular (BV) outflow tract and 13 with left ventricular V T. In RV outflow tract idiopathic VT, RF ablation was successful in 29 of 35 patients (83%), The following information allowed differentiati on between patients with and without a successful RF ablation: >1 indu ced VT morphology (0 vs 3); presence of delta wave-like beginning of t he QRS (2 vs 3) and greater than or equal to 11 of 12 leads showing a ''match'' between the clinical VT and the pacemap (28 vs 1). Endocardi al activation times were not different between both groups (-15 +/- 18 vs -4 +/- 5 ms). In left ventricle idiopathic VT, RF ablation was suc cessful in 12 of 13 patients (92%). In patients who underwent successf ul ablation, 1 VT morphology was induced and no delta wave-like beginn ing of the QRS was present; a correlation between clinical VT and the pacemap greater than or equal to 11 of 12 leads was found and the endo cardial activation time preceded the QRS (range of -5 to -58 ms [mean -30 +/- 14]). Purkinje activity was observed in 5 of 7 patients with a n idiopathic VT originating from the inferoposterior region but not fr om the inferoapical region of the left ventricle. Four patients (14%) with RV outflow tract idiopathic VT had recurrence during a mean follo w-up of 2 to 50 months (mean 30 +/- 12). Thus, (1) in RV outflow tract idiopathic VT a goad pacemap was more important than an early endocar dial activation time; (2) an optimal pacemap as well as an early endoc ardial activation time were important predictors for successful ablati on of the left ventricle idiopathic VT; (3) Purkinje activity was reco rded in VTs arising in the inferoposterior region of the left ventricl e; and (4) factors for unsuccessful ablation for idiopathic VT were >1 induced VT morphology, a delta wave-like beginning of the QRS, and a VT/pacemap correlation <11 of 12 leads. Idiopathic VT can be successfu lly ablated with both immediate and long-term success. (C) 1997 by Exc erpta Medica, Inc.