[Atrial defibrillators]

The promising results achieved with low-energy, internal atrial cardioversion have stimulated the development of an implantable atrial defibrillator. Initial clinical experience with the Metrix system in a group of highly selected patients with refractory atrial fibrillation (AF) suggests that atrial defibrillation can be performed effectively and safely by using a stand-alone device. The extension of this therapy will depend on the results of further prospective studies comparing this new therapeutic option with other new non-pharmacological methods to treat AF. Internal atrial cardioversion is feasible at low energies with current endocardial transvenous lead configurations primarily designed for ventricular defibrillation. As AF is a frequent arrhythmia in implantable cardioverter defibrillator recipients, the capability for atrial defibrillation has recently been incorporated in a newly designed dual chamber defibrillator (Jewel AF system). Initial clinical experience with this device that combines both detection and treatment in the atrium as well as in the ventricle indicates a significant improvement in the management of patients with both supraventricular and ventricular tachyarrhythmias.