Eleven patients with sustained ventricular tachycardia (VT) refractory to antiarrhythmic drugs due to right ventricular disease shown by angiography underwent fulguration. Seven patients always had VT with the same morphology, and 4 had clinical VT with 2 or 3 different QRS waveforms. Five patients underwent a single fulguration and the other 6 underwent from 2 to 5 procedures; 2 to 14 shocks (mean 6) of 150 to 250 J were used. No serious complications occurred. At 31.5 +/- 9 months of follow-up, the arrhythmia was controlled in 8 patients, with continuation of previously ineffective antiarrhythmic drug therapy in 6 of 8. The number of VT episodes the year before and after fulguration was 0.5 +/- 0.7 vs 3.5 +/- 1.7 (p less than 0.001). There was no statistically significant difference between the success rate and the degree of prematurity of the onset of the local electrogram during VT: -36 +/- 31 ms for successes and -38 +/- 13 ms for failures. In 7 patients with monomorphic VT, there were 6 successes and 1 failure, and in 4 patients with several morphologies of VT, there were 2 successes and 2 failures (1 due to the appearance of a "new" VT). Thus, electrical fulguration of VT in patients with right ventricular disease is safe and most often effective, particularly in patients with monomorphic VT, when combined with antiarrhythmic drugs. In these patients, the usually recommended endocardial mapping criteria for the determination of the optimal fulguration site were not predictive of outcome. Further studies are necessary to better define the optimal site for fulguration.