[Atrial defibrillator: dream or reality?].

The experience acquired with the use of automatic ventricular cardiovertor-defibrillator led to the idea of developing an atrial device capable of automatically detecting and reducing atrial fibrillation. The large group of patients with paroxysmal atrial fibrillation not responding to pharmacological therapy makes this a particularly relevant question. The first problem is to define the need of this type of device. There is only one group of patients with resistant and/or poorly tolerated paroxysmal atrial fibrillation in whom non-pharmacological therapy is considered, for example ablation of the AV node with implantation of a pacemaker or surgery. The second problem concerns the technical feasibility of an atrial defibrillator with the difficulty related to the detection of the arrhythmia and atrial defibrillation. The recognition of atrial fibrillation may be envisaged from endocavitary signals with satisfactory specificity and sensitivity. The problems related to atrial defibrillation with low energy shocks have not yet been solved clinically, although experimental studies have given promising results. The possible dangers are dominated by a pro-arrhythmic effect and the risk of ventricular fibrillation, but they could be avoided by synchronizing the atrial shock with ventricular activation based on results also obtained in the animal. Before the dream becomes reality, trials are necessary to develop a safe and effective automatic device. Intermediary stages of evaluation of such a device could include a device activated by the physician.