Dual-electrogram based control of cardiac resynchronization therapy

A system for controlling delivery of cardiac resynchronization therapy (CRT) to a patient, the system comprising:

• a plurality of electrodes;
• an implantable medical device configured to deliver ventricular pacing to the patient;
• sensing circuitry configured to sense electrical activity of the heart via the plurality of electrodes;
• and
• processing circuitry configured to:
• control the implantable medical device to deliver ventricular pacing according to a sequence of different values of a CRT parameter;
• acquire, via the sensing circuitry and during the delivery of ventricular pacing according to the sequence, a first electrogram and a second electrogram from respective ones of a first vector formed from the plurality of electrodes and a second vector formed from the plurality of electrodes;
• determine, for each of the different values of the CRT parameter, a first activation interval between an occurrence of a first fiducial of a cardiac cycle and a second fiducial of a cardiac cycle detected in the first electrogram and a second activation interval between the occurrence of the first fiducial of the cardiac cycle and the second fiducial of a cardiac cycle detected in the second electrogram;
• determine, for each of the different values of the CRT parameter, a value of a metric of comparison of the first activation interval to the second activation interval, wherein the metric of comparison comprises one or more of a ratio of the first and second activation intervals and a time difference between the first and second activation intervals;
• determine an updated value of the CRT parameter using the metric of comparison;
• and
• control the implantable medical device to deliver the ventricular pacing with the updated value of the CRT parameter.

A system for controlling delivery of cardiac resynchronization therapy (CRT) to a patient, the system comprising:

• a plurality of electrodes;
• an implantable medical device configured to deliver ventricular pacing to the patient;
• sensing circuitry configured to sense electrical activity of the heart via the plurality of electrodes;
• and
• processing circuitry configured to:
• control the implantable medical device to deliver ventricular pacing according to a sequence of different values of an A-V delay;
• acquire, via the sensing circuitry and during the delivery of ventricular pacing according to the sequence, a first electrogram and a second electrogram from respective ones of a first vector formed from the plurality of electrodes and a second vector formed from the plurality of electrodes;
• determine, for each of the different values of the A-V delay, a first activation interval between an occurrence of a first fiducial of a cardiac cycle and a second fiducial of the cardiac cycle detected in the first electrogram and a second activation interval between the occurrence of the first fiducial of the cardiac cycle and the second fiducial of the cardiac cycle detected in the second electrogram;
• determine, for each of the different values of the A-V delay, one or more of a ratio of the first activation interval and the second activation interval and a time difference between the first activation interval and the second activation interval;
• identify one or more of a minimum value of the time difference and a value of the ratio that is closest to a value of 1;
• determine an updated value of the A-V delay based on the identified one or more of the minimum value of the time delay and the value of the ratio that is closest to a value of 1;
• and
• control the implantable medical device to deliver the ventricular pacing with the updated value of the A-V delay to provide CRT.

A non-transitory computer-readable medium storing instructions for causing processing circuitry to perform a method for controlling delivery of cardiac resynchronization therapy (CRT) using a medical device system, the medical device system comprising the processing circuitry, a plurality of electrodes, an implantable medical device configured for implantation within a patient and comprising at least one electrode of the plurality of electrodes, and sensing circuitry configured to sense electrical activity of the heart via the plurality of electrodes, the method comprising:

• controlling the implantable medical device to deliver ventricular pacing according to a sequence of different values of a CRT parameter;
• acquiring, during the delivery of ventricular pacing according to the sequence, a first electrogram and a second electrogram from respective ones of a first vector formed from the plurality of electrodes and a second vector formed from the plurality of electrodes;
• determining, for each of the different values of the CRT parameter, a first activation interval between an occurrence of a first fiducial of a cardiac cycle and a second fiducial of the cardiac cycle determined in the first electrogram and a second activation interval between the occurrence of the first fiducial of the cardiac cycle and the second fiducial of the cardiac cycle determined in the second electrogram;
• determining, for each of the different values of the CRT parameter, a value of a metric of comparison of the first activation interval to the second activation interval;
• identifying a target value of the metric of comparison of the first activation interval to the second activation interval;
• determining an updated value of the CRT parameter based on the identified target value;
• and
• controlling the implantable medical device to deliver the ventricular pacing at the updated value of the CRT parameter to provide CRT.