RESUMEN
The safety and effectiveness of catheter ablation in coronary sinus using radiofre-quency energy was studied in 16 dogs. Radiofrequency energy(1229?711 J) was applied between electrode catheter placed inside coronary sinus and a chest wall patch. Thirteen dogs were killed approximately half an hour after ablation and three 3 to 4 weeks. Lesion of abltion area were 3. 2?1. 8mm in length, 2. 2?1. 7mm in width and 2. 1?1. 0mm in depth. Microscopic examination showed well circumscribed area of coagultion necrosis (acute period)and fibrosis (chronic period). The coronary atery and mitral apparatus were not involved,nor was the endocadium. No arrhyth-mias except occationally atrial or ventricular premature beats were observed. No hemodynamic changes and rupture of coronary sinus occurred in any dog. Large amount of radiofrequency energy can be safely applied to the coronary sinus. The location of the lesions produced suggests that this technique may be useful for interruption of left-sided atioventricular pathways of patients.