EFFICACY OF RADIOFREQUENCY CATHETER ABLATION FOR VENTRICULAR-TACHYCARDIA IN HEALED MYOCARDIAL-INFARCTION

Radiofrequency catheter ablation has been useful in the treatment of v entricular tachycardia (VT) in selected patients with healed myocardia l infarction. Previous studies have demonstrated success rates of 60% to 96% for targeted VT morphologies; however, these studies included p atients only after they have had successful mapping procedures and hav e received radiofrequency lesions, All patients referred for VT ablati on from July 1992 to November 1996 were included in this analysis on a n intention-to-treat basis. Ninety-five procedures were performed in 6 6 patients for 77 distinct presentations with tolerated, sustained VT, Fifty-five procedures were successful (58%) and 40 procedures failed. Reasons for procedural failure included failed radiofrequency applica tion despite adequate WT mapping (21 procedures), no tolerated VT indu ced (12), and aborted procedures due to complications or technical dif ficulties (7), Fifty-five patients (71%) eventually had a successful V T ablation, although 10 required > 1 procedure. This analysis revealed factors that contribute to failure of VT ablation procedures in addit ion to inadequate mapping and lesion formation. Procedural difficultie s, particularly the inability to induce tolerated VT, frequently preve nt successful catheter ablation in patients who present with tolerated , sustained VT. (C) 1998 by Excerpta Medica, Inc.