A combination cardiac stimulator for CRT stimulation and CCM stimulation, which is connected to a rhythm evaluation unit which can either detect a sinus rhythm that is present, or classify an atrial arrhythmia, and which comprises an additional therapy selection unit, wherein the therapy selection unit selects the delivery of either CRT therapy or CCM therapy on the basis of the classification of the atrial rhythm such that CRT therapy is preferred in the case of sinus rhythm, and CCM therapy is delivered in the case of atrial arrhythmia.
