Criteria for determination of local tissue latency near pacing electrode

1. A cardiac pacemaker, comprising:

(a) a pulse generator configured to deliver a pacing pulse to a patient's ventricle at an atrioventricular (AV) delay following a preceding atrial event;

(b) a sensing circuitry configured to sense a signal from the patient's ventricle following delivery of a said pacing pulse;

(c) a processing circuitry coupled to the pulse generator and the sensing circuitry and configured to control the pulse generator, the processing circuitry further configured to:

(1) acquire from the sensed signal a set of features comprising minimum amplitude, a minimum time (Tmin) associated with the minimum amplitude (Minamp), maximum amplitude, a maximum time (Tmax) associated with the maximum amplitude (Maxamp);

(2) determine whether the ventricular pacing pulse effectively captures the patient's ventricle using the set of features;

(3) determine whether one or more tissue latency conditions are present, the latency conditions comprising:

a) |Maxamp−Minamp|/|Tmax−Tmin) is less than a predetermined ratio; and

b.) |Minamp| is less than a predetermined threshold and effective capture is present;

(4) adjust one or more pacing pulse parameters, in response to determining that tissue latency is present, the pacing pulse parameters being one or more of AV delay, inter-ventricular (VV) delay, pacing vector, and pacing output; and

(5) control the pulse generator to thereafter deliver pacing pulses having the adjusted one or more pacing pulse parameters.

2. A cardiac pacemaker according to claim 1 wherein the predetermined ratio is about 0.1 mV/ms.

3. A cardiac pacemaker according to claim 1 wherein a multipolar lead is employed to deliver pacing stimulus to a left ventricle.

4. A cardiac pacemaker according to claim 3 wherein a lead is employed to deliver pacing stimulus to a right ventricle.

5. A cardiac pacemaker according to claim 4 wherein the multipolar lead comprises four or more electrodes.

6. A cardiac pacemaker according to claim 4 wherein the processing circuitry is further configured to determine presence of tissue latency in response to delivery of pacing stimulus, wherein the Minamp is less than a prespecified amplitude threshold.

7. A cardiac pacemaker according to claim 4 wherein the processing circuitry further configured to determine presence of tissue latency in response to delivery of pacing stimulus, wherein the ratio of (|Maxamp−Minamp|/|Tmax−Tmin|) is less than a predetermined ratio.

8. A cardiac pacemaker according to claim 7 further comprising:

a graphical user interface for displaying presence of tissue latency at a LV electrode in response to delivery of pacing stimulus.

9. A cardiac pacemaker according to claim 3 wherein the multipolar lead comprises four or more left ventricular (LV) electrodes, each electrode is paced at a short AV delay less (<) than or equal 60 milliseconds (ms) with sufficient energy for LV capture while non-paced LV electrodes can be used for sensing a response to the delivered pace.

10. A cardiac pacemaker of claim 9 wherein the AV delay decreased by a prespecified level being one of 5 ms, 10 ms, 15 ms, 20 ms, 25 ms, 30 ms, 35 ms, and 50 ms.

11. A cardiac pacemaker of claim 3 wherein the AV delay is shortened to a short AV delay in response to determining that the

(|Maxamp−Minamp|/|Tmax−Tmin|) is less than a predetermined ratio.

12. A cardiac pacemaker of claim 3 wherein the AV delay is shortened to be less than or equal to 80 ms.

13. A cardiac pacemaker of claim 1 wherein a processing circuitry is configured for determining local tissue latency exists in response to determining that the (|Maxamp−Minamp|/|Tmax−Tmin|) is less than a predetermined ratio.

14. A cardiac pacemaker of claim 1 , wherein acquiring the signal comprises selecting a sensing vector comprising a left ventricular electrode and a right ventricular coil electrode.

15. A cardiac pacemaker of claim 1 , wherein the signal generator is configured to deliver a biventricular pacing at the short AV delay.

16. A cardiac pacemaker of claim 1 , wherein the processing circuitry further configured to adjust the VV delay so that the left ventricular pacing stimulus is delivered ahead of the right ventricular pacing stimulus.

17. A cardiac pacemaker of claim 1 , wherein the left ventricular pacing stimulus is delivered ahead of the right ventricular pacing stimulus in about 5 ms or more, 10 ms or more, 15 ms or more, 20 ms or more, 25 ms or more, 30 ms or more, 35 ms or more, and 40 ms or more.

18. A non-transitory, computer-readable storage medium comprising instructions that, when executed, cause a processor included in a medical device system to:

(a) deliver a left ventricular pacing stimulus at a short atrioventricular (AV) delay equal to or less than 60 ms;

(b) sense a signal in response to the ventricular pacing stimulus;

(c) determine from the signal a minimum time (Tmin) associated with the minimum amplitude (Minamp) determining from the signal a minimum amplitude, a minimum time (Tmin) associated with the minimum amplitude, maximum amplitude, a maximum time (Tmax) associated with the maximum amplitude (Maxamp);

(d) determine whether (|Maxamp−Minamp|/|Tmax−Tmin|) is less than a predetermined ratio; and

(e) determine whether to adjust one or more control pacing parameters, in response to determining whether

(|Maxamp−Minamp|/|Tmax−Tmin|) is less than the predetermined ratio, wherein the control pacing parameters being one of AV delay, inter-ventricular (VV) delay, pacing vector, and pacing output.

19. A method of using an implantable pacemaker, comprising:

(a) delivering, with the pacemaker, a pacing pulse to a patient's ventricle at an atrioventricular (AV) delay following a preceding atrial event;

(b) sensing, with the pacemaker, a signal from the patient's ventricle following delivery of a said pacing pulse;

(c) acquiring from the sensed signal, with the pacemaker, a set of features comprising minimum amplitude, a minimum time (Tmin) associated with the minimum amplitude (Minamp), maximum amplitude, a maximum time (Tmax) associated with the maximum amplitude (Maxamp);

(d) determining, with the pacemaker, whether the ventricular pacing pulse effectively captures the patient's ventricle using the set of features;

(e) determining, with the pacemaker, whether one or more tissue latency conditions are present, the latency conditions comprising:

a) |Maxamp−Minamp|/|Tmax−Tmin) is less than a predetermined ratio; and

b.) |Minamp| is less than a predetermined threshold and effective capture is present;

(f) adjusting, with the pacemaker, one or more pacing pulse parameters, in response to determining that tissue latency is present, the pacing pulse parameters being one or more of AV delay, inter-ventricular (VV) delay, pacing vector, and pacing output; and

(g) controlling, with the pacemaker, the pulse generator to thereafter deliver pacing pulses having the adjusted one or more pacing pulse parameters.

20. A medical device system configured to perform the method of claim 19 .

21. A computer-readable storage medium comprising instructions that, when executed by processing circuitry of a medical device system, cause the processing circuitry to perform the method of claim 19 .