Antitachycardiac stimulator

1. 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.

2. The implantable cardiac stimulator according to claim 1 , wherein the analyzer unit ( 200 ) is configured to generate the ATP response signal that indicates the supraventricular tachycardia SVT when the comparison of the atrial rhythm pattern reveals that an atrial rhythm remains uninfluenced by the ventricular ATP.

3. The implantable cardiac stimulator according to claim 1 , wherein the analyzer unit ( 200 ) is configured to confirm the ventricular tachycardia VT and to generate the ATP response signal that indicates the ventricular tachycardia VT when the comparison of the atrial rhythm pattern reveals that an atrial rhythm is modulated by the ventricular ATP.

4. The implantable cardiac stimulator according to claim 1 , wherein the ventricular sensing unit ( 58 ; 66 ) is connected or connectable to a left ventricular or right ventricular sensing electrode and is configured to detect electric potentials of a respective heart chamber and analyze the electric potentials with respect to the chamber contraction.

5. The implantable cardiac stimulator according to claim 1 , wherein the atrial sensing unit ( 62 ) is connected or connectable to an atrial sensing electrode and is configured to detect electric potentials of an atrium or a right atrium of the heart.

6. The implantable cardiac stimulator according to claim 1 , wherein the tachycardia detection unit ( 170 ) is configured to assign a current ventricular rhythm to at least one VT zone and one VF zone.

7. The implantable cardiac stimulator according to claim 1 , further comprising a defibrillation shock generator ( 50 ), which is connected or connectable to a defibrillation shock electrode ( 38 ) and is configured to generate and deliver a defibrillation shock for defibrillation of at least one chamber.

8. The implantable cardiac stimulator according to claim 7 , wherein the treatment control unit ( 190 ) is configured to inhibit delivery of the defibrillation shock when the ATP response signal indicates occurrence of the supraventricular tachycardia SVT.

9. The implantable cardiac stimulator according to claim 7 , wherein the treatment control unit ( 190 ) is configured to inhibit delivery of a defibrillation shock when the ATP response signal indicates occurrence of the supraventricular tachycardia SVT and a respective ventricular heart rate is in the at least one VT zone.

10. The implantable cardiac stimulator according to claim 1 , wherein the analyzer unit ( 200 ) is configured to analyze an atrial rhythm immediately after the antitachycardiac stimulation ATP compared with the atrial rhythm immediately before the antitachycardiac stimulation ATP.

11. The implantable cardiac stimulator according to claim 1 , wherein the treatment control unit ( 190 ) is configured to inhibit a subsequent antitachycardiac treatment with the function of the ATP response signal.

12. The implantable cardiac stimulator according to claim 1 , wherein the treatment control unit ( 190 ) is configured to continue a subsequent antitachycardiac treatment with the function of the ATP response signal.

13. The implantable cardiac stimulator according to claim 1 , wherein the treatment control unit ( 190 ) is configured to replace a subsequent antitachycardiac ventricular therapy with the function of the ATP response signal by an atrial antitachycardiac therapy.

14. The implantable cardiac stimulator according to claim 1 , wherein the treatment control unit ( 190 ) is configured to first start a new VT/SVT classification with the function of the ATP response signal.

15. The implantable cardiac stimulator according to claim 1 , wherein the treatment control unit ( 190 ) is configured to adapt a subsequent antitachycardiac treatment with the function of the ATP response signal based on parameters of a ventricular antitachycardiac therapy.