Intracardiac electrode catheter ablation of arrhythmogenic foci, using cumulative high energy, was attempted in 29 patients (mean age 57 +/- 15 years) presenting with ventricular tachycardia (VT) refractory to antiarrhythmic drugs. A heart disease, present in 25 patients, was responsible for severe heart failure in 10 of them; 13 patients had myocardial infarction, 7 had arrhythmogenic dysplasia of the right ventricle, 5 had cardiomyopathy (dilated in 4, hypertrophic in 1). The myocardium was apparently normal in 4 patients, 2 of whom had mitral valve prolapse. Morphologically, VT was single in 20 cases, double in 4 cases and more than triple in 5 cases; arrhythmia was continual or occurred several times a day in 17 cases. In one (20 patients) or several (9 patients) catheter ablation sessions, 1 to 16 cathodic shocks of 160 to 240 Joules (1.180 +/- 1.062 J) were delivered after mapping and focal stimulation without irreversible adverse reaction. The cumulative energy delivered was 840 +/- 558 J in the right ventricle (11 patients) and 1.390 +/- 1.244 J in the left ventricle (18 patients). During a 23.4 +/- 12 months follow-up period, 4 patients died (2 of heart failure, 1 of a hitherto undocumented VT, 1 suddenly of bradycardia-asystole). VT was regarded as being controlled in 23/27 patients, 15 of whom were not taking antiarrhythmic agents. The presystolic potential during VT was -5 + 5 ms in the 4 failure cases versus -41 + 29 ms in the successful cases (p less than 0.05). It is concluded that electrode catheter ablation is an effective curative treatment of VT.(ABSTRACT TRUNCATED AT 250 WORDS)