Abstract
The mortality of patients with congestive heart failure is high despite advences in medical therapy. Implantable devices can prevent some of the complications of heart failure, in selected cases even the pathomechanism can be altered. Implantable cardioverter-defibrillators are remarkably efficient in the prevention of sudden cardiac death caused by malignant tachyarrhythmias. Cardiac resynchronization therapy beneficially affects the hemodynamics by correcting the intraventricular conduction disorder. The effects of the implantable devices are additive to the optimal medical therapy. In some cases, such as chronic right ventricular stimulation during conventional pacemaker therapy, the harmful effects have been recognized. The results of the new clinical studies lead to the expansion of indications of device-based heart failure therapy, a rise in the number of implantations can be expected.