The invention relates to a pacemaker system comprising: - a control unit which includes an energy source, an electronic controller and a first electrical contact surface, - a first probe to be disposed in or on a first ventricle； characterised by - a first mounting arrangement that can be inserted in a blood vessel, - a mounting element for detachably securing the control unit to the mounting arrangement, and - a first electrical contact element which is electrically connected to the first probe and is in electrical contact with the first contact surface when the control unit is secured to the mounting arrangement.
