Abstract: A defibrillator comprising an implantable housing (10) and an implantable electrode set which includes at least a right-ventricular electrode (2) and a coronary sinus electrode (3), wherein arranged in the housing (10) is a control device (11) for the electrodes of the electrode set wherein the housing (10) is conducting and is connected as an electrode.

Abstract: A device for determining tachycardial heart rhythm disturbances, comprising: a stimulation pulse generator; a ventricular stimulation electrode; an electrode line; one sensor electrode each in the atrium and ventricle of a heart; an atrial action detecting device; a ventricular action detecting device; a timer; an atrial interval detecting device; a ventricular interval detecting device; a comparator unit which compares the chronological spacings of successive atrial actions and successive ventricular actions and outputs a stimulation inducing signal; an evaluation device for detecting and evaluating changes, caused by the ventricular stimulation pulse in the atrial intervals and for outputting a tachycardia classification signal that characterizes the outcome of the evaluation; and a stimulation control device connected on the output side to the stimulation pulse generator, for controlling the output of a train of stimulation pulses at such intervals as occur between the stimulation pulses of a plurality of