Recovery of cardiac event sensing and rhythm detection following electrical stimulation pulse delivery

1. A method comprising:

determining a pre-shock cardiac event amplitude;

delivering an electrical shock to a heart of a patient, wherein the electrical shock is delivered to the heart via a plurality of electrodes; and

adjusting, by a medical device and responsive to delivering the electrical shock, a cardiac sensing threshold to decay from an initial amplitude at a post-shock decay rate, wherein the post-shock decay rate is based on the pre-shock cardiac event amplitude.

2. The method of claim 1 , wherein adjusting the cardiac sensing threshold includes:

setting the initial amplitude of the cardiac sensing threshold.

3. The method of claim 2 , wherein the initial amplitude is based on the pre-shock cardiac event amplitude.

4. The method of claim 1 , the method further comprising:

identifying, prior to delivering the electrical shock and based on the cardiac sensing threshold, pre-shock cardiac events during a pre-shock drop interval.

5. The method of claim 4 , wherein delivering the electrical shock to the heart of the patient includes:

delivering the electrical shock in response to the pre-shock cardiac events satisfying a therapy delivery criterion.

6. The method of claim 4 , further comprising:

adjusting, by the medical device and prior to delivering the electrical shock, the cardiac sensing threshold to decay at a pre-shock decay rate during the pre-shock drop interval.

7. The method of claim 4 , wherein the post-shock decay rate is a first post-shock decay rate, wherein the cardiac sensing threshold decays at the first post-shock decay rate during a first post-shock drop interval, and wherein adjusting the cardiac sensing threshold includes:

adjusting the cardiac sensing threshold to decay at a second post-shock decay rate during a second post-shock drop interval that follows the first post-shock drop interval.

8. The method of claim 7 , wherein the second post-shock decay rate is based on the pre-shock cardiac event amplitude.

9. The method of claim 7 , wherein the second post-shock drop interval is longer than the first post-shock drop interval and shorter than the pre-shock drop interval.

10. The method of claim 1 , wherein the post-shock decay rate is a first post-shock decay rate, the method further comprising:

identifying, by the medical device and based on the cardiac sensing threshold, post-shock cardiac events, including at least one post-shock cardiac electrical signal crossing the cardiac sensing threshold; and

adjusting, by the medical device and in response to identifying the post-shock cardiac events, the cardiac sensing threshold to decay at a second post-shock decay rate.

11. The method of claim 10 , wherein the second post-shock decay rate is based on the pre-shock cardiac event amplitude.

12. The method of claim 1 , wherein the electrical shock is at least 10 Joules.

13. A medical device comprising:

sensing circuitry configured to detect cardiac events of a heart of a patient using a cardiac sensing threshold;

therapy delivery circuitry configured to deliver an electrical shock to the heart via a plurality of electrodes coupled to the medical device; and

processing circuitry configured to perform operations comprising:

determining a pre-shock cardiac event amplitude; and

responsive to delivering the electrical shock, adjusting the cardiac sensing threshold to decay from an initial amplitude at a post-shock decay rate, wherein the post-shock decay rate is based on the pre-shock cardiac event amplitude.

14. The medical device of claim 13 , wherein adjusting the cardiac sensing threshold includes:

setting the initial amplitude of the cardiac sensing threshold.

15. The medical device of claim 14 , wherein the initial amplitude is based on the pre-shock cardiac event amplitude.

16. The medical device of claim 13 , wherein the processing circuitry is further configured to perform operations comprising:

identifying, prior to delivering the electrical shock and based on the cardiac sensing threshold, pre-shock cardiac events during a pre-shock drop interval.

17. The medical device of claim 16 , wherein the processing circuitry is further configured to perform operations comprising:

controlling the therapy delivery circuitry to deliver the electrical shock in response to the pre-shock cardiac events satisfying a therapy delivery criterion.

18. The medical device of claim 16 , wherein the processing circuitry is further configured to perform operations comprising:

adjusting, prior to the delivery of the electrical shock, the cardiac sensing threshold to decay at a pre-shock decay rate during the pre-shock drop interval.

19. The medical device of claim 16 , wherein the post-shock decay rate is a first post-shock decay rate, wherein the cardiac sensing threshold decays at the first post-shock decay rate during a first post-shock drop interval, and wherein adjusting the cardiac sensing threshold includes:

adjusting the cardiac sensing threshold to decay at a second post-shock decay rate during a second post-shock drop interval that follows the first post-shock drop interval.

20. A non-transitory computer-readable storage medium comprising instructions that, when executed, configure processing circuitry of a medical device to:

determine a pre-shock cardiac event amplitude;

sense delivery of an electrical shock to a heart of a patient; and

adjust, responsive to delivering the electrical shock, a cardiac sensing threshold to decay from an initial amplitude at a post-shock decay rate, wherein the post-shock decay rate is based on the pre-shock cardiac event amplitude.