Between October 1982 and May 1986, 12 patients were implanted with an automatic defibrillator AID-B; 7 had coronary artery disease, 2 had dilated cardiomyopathies and 3 had torsades de pointe with or without long QT intervals. Five patients had a thoracic approach with a left ventricular patch and implantation of a right atrial endocavitary electrode. Thereafter a subcostal approach was used with 2 patch electrodes. Two of the first 5 patients rejected the device, but this complication was not observed in the remaining 7 cases. The threshold of defibrillation was greater than 25 joules in 1 case out of 5 with a patch and endocavitary electrode. This threshold was less than 25 joules in all patients with 2 patch electrodes. The AID-B was triggered in less than 20 seconds. One patient died of pulmonary embolism 8 days after implantation; 2 others had a temporary aggravation of their arrhythmias. There were no cases of inappropriate activation of the AID-B device during follow up: 5 patients had no arrhythmia or defibrillation. The 6 others had 2 to 35 defibrillations with documented arrhythmias before or after defibrillation. One patient suffered a sudden death after exhaustion of the device which had functioned on two occasions but had not been replaced for economic reasons. The technique of implantation has been simplified, so limiting local complications. This device is reliable and represents an effective palliative treatment of sudden death due to ventricular arrhythmias.