Patent ID: 7983752

Claim:
An implantable cardiac stimulator, comprising a chamber stimulation unit ( 56 ; 64 ), which is connected or connectable to a left ventricular or right ventricular stimulation electrode to generate and deliver chamber stimulation pulses for stimulation of a ventricle of a heart; a ventricular sensing unit ( 58 ; 66 ), which is configured to detect a respective chamber contraction and to deliver a ventricular sensing signal when a chamber contraction is detected; an atrial sensing unit ( 62 ), which is configured to detect an atrial contraction and to deliver an atrial sensing signal that indicates a respective atrial event when the atrial contraction is detected; a tachycardia detection unit ( 170 ), which is connected to at least one ventricular sensing unit comprising said ventricular sensing unit and is configured to detect a tachycardia and to categorize the tachycardia as a ventricular tachycardia VT or as a supraventricular tachycardia SVT; a treatment control unit ( 190 ), which is configured to trigger at least the chamber stimulation unit ( 56 ; 64 ) to deliver antitachycardiac stimulation ATP; and, an analyzer unit ( 200 ), which is connected to the atrial sensing unit ( 62 ) and to the treatment control unit wherein the analyzer unit is configured to analyze atrial events detected by the atrial sensing unit ( 62 ) before, during and after delivery of the antitachycardiac stimulation ATP with regard to an atrial rhythm pattern during ventricular ATP by comparison with the atrial rhythm pattern immediately before ATP and to trigger the treatment control unit ( 190 ) as a function of an ATP response signal that represents a result of the comparison for selection of a following antitachycardiac treatment.