An implantable direct-current electrode assembly (20, 120) has two implantable electrodes (30； 40) and a control circuit (50), to which the first and the second electrodes (30； 40) are electrically connected. The control circuit (50) is designed to establish a potential difference between the two electrodes (30； 40), so that a direct current (55) can flow between the two electrodes (30； 40). One of the electrodes (30) is a coil electrode with a maximum length that is pre-determined by the distance between the tricuspid valve and the end of the right ventricle lying opposite the tricuspid valve and the pulmonary valve. The counter-electrode (40) can be a coil electrode for the coronary sinus, or a plate electrode that can be attached to the exterior of the left ventricle.
