RADIOFREQUENCY CATHETER ABLATION OF VENTR ICULAR-TACHYCARDIA

Radiofrequency energy was used for the ablation of chronic recurrent v entricular tachycardia (VT) in 58 patients who were divided into two g roups: 44 cases with structural myocardial disease (36 men and 8 women : mean age 55 years; range : 14 to 85 years) with an average left ven tricular ejection fraction of 38% (range: 15 to 80%) : these patients had myocardial infarction (28 cases), arrythmogenic right ventricular dysplasia (11 cases), idiopathic dilated cardiomyopathy (2 cases), ope rated congenital heart disease (2 cases) and operated valvular heart d isease (1 case). The clinical success rate after the first session of radiofrequency ablation was 34%. When (according to our modified proto col of fulguration) 160 joule cathodal shocks were delivered to the sa me catheter previously used for RF ablation during the same session or secondarily (13 cases), the success rate increased to 76%. The averag e follow-up period of the 37 survivors was 16.7 months. The second gro up consists of 14 cases without structural myocardial disease (10 men and 4 women, mean age 41 years, range 14 to 69 years) with an average left ventricular ejection fraction of 61%. These patients had idiopath ic ventricular tachycardia(10 cases) and verapamil-sensitive ventricul ar tachycardia (4 cases). The primary success of radiofrequency ablati on alone was 43%. When combined with fulguration during the same of ra diofrequency ablation alone was 43%. When combined fulguration during the same of at a later session, the success rate increased to 71.3%. T he average follow-up period of the 13 survivors was 19 months (range 0 .3 to 39 months). No significant difference was observed between the g roups with or without structural myocardial disease after radiofrequen cy or fulguration ablation, not only with respect to global results bu t also after analysis of subgroups with, for example, post-infarction ventricular tachycardia or arrhythmogenic right ventricular dysplasia. However, clinical success was obtained after a single session of radi ofrequency ablation alone in 8 of the 9 cases of incessant ventricular tachycardia in patients with structural myocardial disease.