Complete data concerning long-term results of transcatheter electrical ablation of the atrioventricular junction is not available. At the request of the French Cardiac Arrhythmia Working group we undertook an inquiry in October 1983. All centers potentially able to perform such procedures were asked to report their experience. Eight centers have performed one case or more, over a period of 3 years, for a total of 91 patients. The mean follow-up completed in all patients in April 1986 was 12 +/- 10 months. The procedure was indicated for a supraventricular arrhythmia resistant to a mean of 3.9 +/- 1.3 classes of antiarrhythmic agents. Atrial flutter or fibrillation in 54 (59%) and atrioventricular nodal reentry in 17 (18%) were the most common arrhythmias. A mean of 2.6 +/- 2.3 electrical shocks (range 1-14 shocks) with a stored energy of 130-400 joules was delivered during 1-5 sessions. Complete heart block was obtained in 83 patients and persisted at the time of discharge from the hospital in 46 patients (50.5%). The immediate complication (within 24 hours after the procedure) included ventricular fibrillation successfully converted (one patient) and nonsustained ventricular tachycardia (three patients). Late complications included one death 3 days after the procedure, in a patient in whom sustained ventricular tachycardia was documented, nonsustained ventricular tachycardia in two patients, sepsis in three patients and pericardial effusion in one patient. At the time of the follow-up, there were three additional deaths related to sepsis due to pacemaker pocket infection in one patient and to preexisting congestive heart failure in two patients.(ABSTRACT TRUNCATED AT 250 WORDS)