THE IMPLANTABLE DEFIBRILLATOR OR ATRIOVERTOR - INITIAL RESULTS

The atrial defibrillator is a new non-pharmacological treatment of atr ial fibrillation (AF) for restoration of sinus rhythm. This device has two programmable modes : automatic or activated by the physician or p atient. In the automatic mode, the device delivers a shock synchronous with the R wave to restore sinus rhythm when AF is detected. Two pati ents with paroxysmal AF resistant to pharmacological therapy were incl uded in a study to assess the efficacy and safety of the atrial defibr illator in the mode activated by the physician. The device implanted i n the pectoral region is connected to 3 electrodes, two for atrial def ibrillation and sensing positioned in the coronary sinus and right atr ium respectively and a sensing and pacing electrode in the right ventr icle. The right ventricle is paced if a post-shock pause is detected. It is possible to interrogate the device with a programmer using its H olter function and so determine the number of episodes of AF sensed an d treated. The number, intensity and energy of the shocks and the para meters of ventricular stimulation are programmable. In these two patie nts, the atrial defibrillator effectively reduced prolonged episodes o f AF with a follow-up of 12 and 7 months. No pro-arrhythmic effects we re observed. Further clinical evaluation is under way to assess this n ew mode of treatment, including the mode activated by the patient, saf ety and tolerance of the shocks. In our two patients, the treatment of prolonged episodes of AF was followed by reduction of many short or a symptomatic episodes.