Electrical devices, Cardiac Resynchronization Therapy (CRT) pacemakers, the Implantable Cardiac Defibrillator (ICD) and a combination of both, constitute an important line of treatment in the therapy of moderate to severe chronic heart failure. The effectiveness of these devices in the treatment of acute decompensated heart failure has yet to be systematically evaluated. However, the beneficial clinical effects of CRT translate into a marked reduction of heart failure-related hospitalization. Devices also offer unique diagnostic applications by continuous measurement of clinically useful physiological parameters over time. Of particular interest, monitoring of intrathoracic impedance and right ventricular pressures allows to detect changes in volume load in an early stage prior to the development of clinical symptoms. This information could be helpful to stop further progression to acute cardiac decompensation and to avoid hospitalization and acute clinical events. Using modern telecommunication technology, patients can also be remotely monitored in their daily living environment. In consequence, the incorporation of device technology into heart failure management programs calls for a close cooperation between heart failure specialists and electrophysiologists. This review addresses therapeutic and diagnostic aspects of device therapies in the context of acute heart failure.