Catheter ablation of ventricular tachycardia in patients with structural heart disease using cooled radiofrequency energy - Results of a prospective multicenter study

OBJECTIVES The purpose of this multicenter study was to evaluate the safety and efficacy of a radiofrequency (RF) catheter ablation system with intern al saline irrigation. BACKGROUND Catheter ablation of ventricular tachycardia (VT) associated wit h structural heart disease is more difficult than ablation of idiopathic VT . The larger size of responsible reentrant circuits contributes to the diff iculty in achieving an adequate ablation lesion with conventional technique s. Recently, cooling of the ablation electrode by saline irrigation has bee n shown to increase RF lesion size. METHODS The patient population included 146 patients who participated in th e Cooled RF Ablation System clinical trial and underwent an attempt at abla tion of VT occurring in the presence of structural heart disease. The durat ion of follow-up was 243 +/- 153 days. RESULTS Catheter ablation was acutely successful, as defined by elimination of all mappable VTs, in 106 patients (75%). In 59 patients (41%), no VT of any type was inducible after ablation. Twelve patients (8%) experienced a major complication. lifter catheter ablation, 66 patients (46%) developed o ne or more episodes of a sustained ventricular arrhythmia. CONCLUSIONS The results of this study demonstrate that catheter ablation of all mappable forms of sustained VT can be performed with high initial succ ess and a moderate incidence of major complications (8%). (J Am Coll Cardio l 2000;35:1905-14) (C) 2000 by the American College of Cardiology.