Delivery of left ventricular pacing therapy during cardiac resynchronization therapy in a cardiac medical device and medical device system

1. A method of delivering left ventricular pacing in a medical device system, comprising:

sensing a subcutaneous cardiac signal and emitting a trigger signal in response to the sensed cardiac signal;

delivering the left ventricular pacing in response to the emitted trigger signal;

employing the device system to determine whether the medical device system is in one of a VVD mode wherein the sensed subcutaneous cardiac signal is associated with both an atrial and a ventricular signal and a VVI mode wherein the sensed subcutaneous cardiac signal is associated with only a ventricular signal;

employing the device system to determine whether the delivered left ventricular pacing captures the left ventricle;

employing the device system to determine whether to adjust a pacing parameter in response to the determination of whether the device system is in one of the VVD mode and the VVI mode and the determination of whether the delivered left ventricular pacing captures the left ventricle; and

delivering the left ventricular pacing in response to determining whether to adjust the pacing parameter; and further comprising:

comparing a beat of a subcutaneous cardiac signal sensed in response to the left ventricular pacing to a baseline intrinsic template associated with a non-paced beat; and

adjusting an atrioventricular delay of the left ventricular pacing in response to the comparing; and further comprising:

employing the device system to determine a correlation between the beat and a baseline intrinsic template;

employing the device system to determine whether the correlation is greater than a correlation threshold;

employing the device system to determine whether the atrial ventricular delay is greater than an atrioventricular delay threshold;

adjusting the atrioventricular delay of the ventricular pacing therapy in response to both the correlation being greater than the correlation threshold and the atrial ventricular delay being greater than the atrioventricular delay threshold;

delivering the adjusted left ventricular pacing; and

wherein adjusting the atrioventricular delay comprises decreasing the atrioventricular delay.

2. A method of delivering left ventricular pacing in a medical device system, comprising:

sensing a subcutaneous cardiac signal and emitting a trigger signal in response to the sensed cardiac signal;

delivering the left ventricular pacing in response to the emitted trigger signal;

employing the device system to determine whether the medical device system is in one of a VVD mode wherein the sensed subcutaneous cardiac signal is associated with both an atrial and a ventricular signal and a VVI mode wherein the sensed subcutaneous cardiac signal is associated with only a ventricular signal;

employing the device system to determine whether the delivered left ventricular pacing captures the left ventricle;

employing the device system to determine whether to adjust a pacing parameter in response to the determination of whether the device system is in one of the VVD mode and the VVI mode and the determination of whether the delivered left ventricular pacing captures the left ventricle; and

delivering the left ventricular pacing in response to determining whether to adjust the pacing parameter; and further comprising:

comparing a beat of a subcutaneous cardiac signal sensed in response to the left ventricular pacing to a baseline intrinsic template associated with a non-paced beat; and

adjusting an atrioventricular delay of the left ventricular pacing in response to the comparing; and further comprising:

employing the device system to determine a correlation between the beat and a baseline intrinsic template;

employing the device system to determine whether the correlation is greater than a correlation threshold;

employing the device system to determine whether the atrial ventricular delay is greater than an atrioventricular delay threshold;

adjusting the atrioventricular delay of the ventricular pacing therapy in response to both the correlation being greater than the correlation threshold and the atrial ventricular delay being greater than the atrioventricular delay threshold;

delivering the adjusted left ventricular pacing;

employing the device system to determine, in response to response to the correlation being greater than the correlation threshold and the atrial ventricular delay not being greater than the atrioventricular delay threshold, whether subsequently delivered left ventricular pacing captures the left ventricle; and

adjusting a pacing output of the left ventricular pacing in response to the subsequently delivered ventricular pacing capturing the left ventricle.

3. A medical device system for delivery ventricular pacing, comprising:

a subcutaneous sensing device comprising a subcutaneous electrode to sense a subcutaneous cardiac signal and an emitting device to emit a trigger signal in response to the sensed cardiac signal;

an intracardiac therapy delivery device to deliver the left ventricular pacing in response to the emitted trigger signal; and

a processor configured to determine whether the medical device system is in one of a VVD mode wherein the sensed subcutaneous cardiac signal is associated with both an atrial and a ventricular signal and a VVI mode wherein the sensed subcutaneous cardiac signal is associated with only a ventricular signal, determine whether the delivered left ventricular pacing captures the left ventricle, determine whether to adjust a pacing parameter in response to the determination of whether the device system is in one of the VVD pacing mode and the VVI pacing mode and the determination of whether the delivered left ventricular pacing captures the left ventricle, and deliver the left ventricular pacing in response to determining whether to adjust the pacing parameter;

wherein the processor is configured to compare a beat of a subcutaneous cardiac signal sensed in response to the left ventricular pacing to a baseline intrinsic template associated with a non-paced beat, and adjust an atrioventricular delay of the left ventricular pacing in response to the comparing: wherein the processor is configured to determine a correlation between the beat and a baseline intrinsic template, determine whether the correlation is greater than a correlation threshold, determine whether the atrial ventricular delay is greater than an atrioventricular delay threshold, adjust the atrioventricular delay of the ventricular pacing therapy in response to both the correlation being greater than the correlation threshold and the atrial ventricular delay being greater than the atrioventricular delay threshold, and deliver the adjusted left ventricular pacing; and

wherein the processor is configured to determine, in response to response to the correlation being greater than the correlation threshold and the atrial ventricular delay not being greater than the atrioventricular delay threshold, whether subsequently delivered left ventricular pacing captures the left ventricle, and adjust a pacing output of the left ventricular pacing in response to the subsequently delivered ventricular pacing capturing the left ventricle.

4. The medical device system of claim 3 , wherein the processor is configured to compare a beat of a subcutaneous cardiac signal sensed in response to the left ventricular pacing to a baseline intrinsic template associated with a non-paced beat and decrease the atrioventricular delay in response to the correlation being greater than a correlation threshold.

5. A medical device system for delivery ventricular pacing, comprising:

a subcutaneous sensing device comprising a subcutaneous electrode to sense a subcutaneous cardiac signal and an emitting device to emit a trigger signal in response to the sensed cardiac signal;

an intracardiac therapy delivery device to deliver the left ventricular pacing in response to the emitted trigger signal; and

a processor configured to determine whether the medical device system is in one of a VVD mode-wherein the sensed subcutaneous cardiac signal is associated with both an atrial and a ventricular signal and a VVI mode wherein the sensed subcutaneous cardiac signal is associated with only a ventricular signal, determine whether the delivered left ventricular pacing captures the left ventricle, determine whether to adjust a pacing parameter in response to the determination of whether the device system is in one of the VVD pacing mode and the VVI pacing mode and the determination of whether the delivered left ventricular pacing captures the left ventricle, and deliver the left ventricular pacing in response to determining whether to adjust the pacing parameter;

wherein the processor is configured to compare a beat of a subcutaneous cardiac signal sensed subsequent to the left ventricular pacing to a baseline intrinsic template associated with a non-paced beat, and adjust a pacing rate of the left ventricular pacing in response to the comparing;

wherein the processor is configured to determine a correlation between the beat and a baseline intrinsic template, perform a first adjusting of the pacing rate in response to the correlation being greater than a correlation threshold, and perform a second adjusting of the pacing rate, different from the first adjusting, in response to the correlation being greater than the correlation threshold; and

wherein the processor is configured to determine, in response to the correlation being greater than the correlation threshold, whether a pacing rate of the ventricular pacing is greater than a minimum pacing rate threshold, and decrease the pacing rate in response to the pacing rate being greater than the minimum pacing rate threshold.

6. The medical device system of claim 5 , wherein the processor is configured to determine, in response to both the correlation not being greater than the correlation threshold and the pacing rate being greater than the maximum pacing rate threshold, whether subsequently delivered left ventricular pacing captures the left ventricle, and adjust a pacing output of the left ventricular pacing in response to the subsequently delivered ventricular pacing capturing the left ventricle.

7. The medical device system of claim 5 , wherein the processor is configured to determine, in response to the correlation not being greater than the correlation threshold, whether a pacing rate of the ventricular pacing is greater than a maximum pacing rate threshold, and increase the pacing rate in response to the pacing rate not being greater than the maximum pacing rate threshold.

8. A subcutaneous medical device for delivering left ventricular pacing therapy, comprising:

a subcutaneous sensing device comprising a subcutaneous electrode to sense a subcutaneous cardiac signal and an emitting device to emit a trigger signal in response to the sensed cardiac signal; and

a processor configured to determine whether the medical device system is in one of a VVD mode wherein the sensed subcutaneous cardiac signal is associated with both an atrial and a ventricular signal and a VVI mode wherein the sensed subcutaneous cardiac signal is associated with only a ventricular signal, determine whether the delivered left ventricular pacing captures the left ventricle, determine whether to adjust a pacing parameter in response to the determination of whether the device system is in one of the VVD mode and the VVI mode and the determination of whether the delivered left ventricular pacing captures the left ventricle, and emit the trigger signal to deliver the left ventricular pacing in response to determining whether to adjust the pacing parameter wherein the processor is configured to compare a beat of a subcutaneous cardiac signal sensed subsequent to the left ventricular pacing to a baseline intrinsic template associated with a non-paced beat, and adjust a pacing rate of the left ventricular pacing in response to the comparing;

wherein the processor is configured to determine a correlation between the beat and a baseline intrinsic template, perform a first adjusting of the pacing rate in response to the correlation being greater than a correlation threshold, and perform a second adjusting of the pacing rate, different from the first adjusting, in response to the correlation being greater than the correlation threshold; and

wherein the processor is configured to determine, in response to the correlation being greater than the correlation threshold, whether a pacing rate of the ventricular pacing is greater than a minimum pacing rate threshold, and decrease the pacing rate in response to the pacing rate being greater than the minimum pacing rate threshold.

9. The subcutaneous medical device of claim 8 , wherein the processor is configured to determine, in response to both the correlation not being greater than the correlation threshold and the pacing rate being greater than the maximum pacing rate threshold, whether subsequently delivered left ventricular pacing captures the left ventricle, and adjust a pacing output of the left ventricular pacing in response to the subsequently delivered ventricular pacing capturing the left ventricle.

10. The subcutaneous medical device of claim 8 , wherein the processor is configured to determine, in response to the correlation not being greater than the correlation threshold, whether a pacing rate of the ventricular pacing is greater than a maximum pacing rate threshold, and increase the pacing rate in response to the pacing rate not being greater than the maximum pacing rate threshold.

11. A medical device system for delivery ventricular pacing, comprising:

a subcutaneous sensing device comprising a subcutaneous electrode to sense a subcutaneous cardiac signal and an emitting device to emit a trigger signal in response to the sensed cardiac signal;

an intracardiac therapy delivery device to deliver the left ventricular pacing in response to the emitted trigger signal; and

a processor configured to determine whether the medical device system is in one of a VVD mode-wherein the sensed subcutaneous cardiac signal is associated with both an atrial and a ventricular signal and a VVI mode wherein the sensed subcutaneous cardiac signal is associated with only a ventricular signal, determine whether the delivered left ventricular pacing captures the left ventricle, determine whether to adjust a pacing parameter in response to the determination of whether the device system is in one of the VVD pacing mode and the VVI pacing mode and the determination of whether the delivered left ventricular pacing captures the left ventricle, and deliver the left ventricular pacing in response to determining whether to adjust the pacing parameter;

wherein the processor is configured to compare a beat of a subcutaneous cardiac signal sensed subsequent to the left ventricular pacing to a baseline intrinsic template associated with a non-paced beat, and adjust a pacing rate of the left ventricular pacing in response to the comparing;

wherein the processor is configured to determine a correlation between the beat and a baseline intrinsic template, perform a first adjusting of the pacing rate in response to the correlation being greater than a correlation threshold, and perform a second adjusting of the pacing rate, different from the first adjusting, in response to the correlation being greater than the correlation threshold; and

wherein the processor is configured to determine, in response to the correlation not being greater than the correlation threshold, whether a pacing rate of the ventricular pacing is greater than a maximum pacing rate threshold, and increase the pacing rate in response to the pacing rate not being greater than the maximum pacing rate threshold.

12. A subcutaneous medical device for delivering left ventricular pacing therapy, comprising:

a subcutaneous sensing device comprising a subcutaneous electrode to sense a subcutaneous cardiac signal and an emitting device to emit a trigger signal in response to the sensed cardiac signal; and

a processor configured to determine whether the medical device system is in one of a VVD mode wherein the sensed subcutaneous cardiac signal is associated with both an atrial and a ventricular signal and a VVI mode wherein the sensed subcutaneous cardiac signal is associated with only a ventricular signal, determine whether the delivered left ventricular pacing captures the left ventricle, determine whether to adjust a pacing parameter in response to the determination of whether the device system is in one of the VVD mode and the VVI mode and the determination of whether the delivered left ventricular pacing captures the left ventricle, and emit the trigger signal to deliver the left ventricular pacing in response to determining whether to adjust the pacing parameter; and

wherein the processor is configured to determine a correlation between the beat and a baseline intrinsic template, determine whether the correlation is greater than a correlation threshold, determine whether the atrial ventricular delay is greater than an atrioventricular delay threshold, adjust the atrioventricular delay of the ventricular pacing therapy in response to both the correlation being greater than the correlation threshold and the atrial ventricular delay being greater than the atrioventricular delay threshold, and deliver the adjusted left ventricular pacing; and

wherein the processor is configured to determine, in response to response to the correlation being greater than the correlation threshold and the atrial ventricular delay not being greater than the atrioventricular delay threshold, whether subsequently delivered left ventricular pacing captures the left ventricle, and adjust a pacing output of the left ventricular pacing in response to the subsequently delivered ventricular pacing capturing the left ventricle.

13. A subcutaneous medical device for delivering left ventricular pacing therapy, comprising:

a subcutaneous sensing device comprising a subcutaneous electrode to sense a subcutaneous cardiac signal and an emitting device to emit a trigger signal in response to the sensed cardiac signal; and

a processor configured to determine whether the medical device system is in one of a VVD mode wherein the sensed subcutaneous cardiac signal is associated with both an atrial and a ventricular signal and a VVI mode wherein the sensed subcutaneous cardiac signal is associated with only a ventricular signal, determine whether the delivered left ventricular pacing captures the left ventricle, determine whether to adjust a pacing parameter in response to the determination of whether the device system is in one of the VVD mode and the VVI mode and the determination of whether the delivered left ventricular pacing captures the left ventricle, and emit the trigger signal to deliver the left ventricular pacing in response to determining whether to adjust the pacing parameter wherein the processor is configured to compare a beat of a subcutaneous cardiac signal sensed subsequent to the left ventricular pacing to a baseline intrinsic template associated with a non-paced beat, and adjust a pacing rate of the left ventricular pacing in response to the comparing;

wherein the processor is configured to determine a correlation between the beat and a baseline intrinsic template, perform a first adjusting of the pacing rate in response to the correlation being greater than a correlation threshold, and perform a second adjusting of the pacing rate, different from the first adjusting, in response to the correlation being greater than the correlation threshold; and

wherein the processor is configured to determine, in response to the correlation not being greater than the correlation threshold, whether a pacing rate of the ventricular pacing is greater than a maximum pacing rate threshold, and increase the pacing rate in response to the pacing rate not being greater than the maximum pacing rate threshold.