Abstract: An electrical therapy device for a heart has a hemodynamic sensor (1), an electrostimulation device (2) and a control unit (30). The hemodynamic sensor (1) is adapted to detect a peripheral blood flow. In this arrangement, the control unit (30) has a tachyarrhythmia evaluation device (3) and a telemetry receiver (6). The control unit (30) controls the electrostimulation device (2) for stimulating and defibrillating the heart in dependence on the peripheral blood flow which is detected by the hemodynamic sensor (1). In addition a tachyarrhythmia and/or the peripheral hemodynamic effects thereof is detected, wherein the peripheral hemodynamic effects of the tachyarrhythmia are determined on the basis of the peripheral blood flow which is detected by a peripheral hemodynamic sensor (1). The results of detecting a tachyarrhythmia and/or the peripheral hemodynamic effects thereof can be used to defibrillate or stimulate the heart by means of the electrostimulation device (2).