Systems, devices and methods relating to endocardial pacing for resynchronization
Tools and methods are particularly suited for certain cardiac conditions advantaged by pacing of the right and left ventricles from a lead in the right ventricle, e.g., to facilitate mechanically and/or electrically synchronous contractions for resynchronization. Certain aspects involve pacing and/or mapping by delivering pulses to a cardiac site useful for improving heart function as measured, e.g., by QRS width, fractionation, late LV activation timing, mechanical synchronicity of free wall and septal wall, effective throughput/pressure, or a combination thereof. Other specific aspects include: determining a pacing threshold, beyond the capture threshold, to improve heart function; delivering pulses of opposite polarity to achieve such heart-function improvement; bi-ventricular pacing from a lead in the right ventricle for such improved heart function; delivering pulses of opposite polarity at a site near the His bundle; electrode-based His-pacing, without penetrating the myocardium; generating and/or delivering multiple pacing profiles including a pacing profile that delivers pulses of opposite polarity and another pacing profile; delivering a pacing profile to generate a synchronous contraction of the septal wall and free wall of the LV from a RV pacing location; and treating one or more of distal LBBB and/or diffuse LBBB by pacing at a site near the His bundle.
1. A method for pacing the left and right ventricles of a heart, the method comprising:
delivering at least one pacing profile via a lead including a distal portion located in the right ventricle and including first and second electrodes, wherein the first electrode is located on a septum near a His bundle of a patient and the second electrode is located less than about 5 to 6 millimeters away from the first electrode, to pace the right and left ventricles and resynchronize at least one of the ventricles and, wherein the step of delivering at least one pacing profile includes concurrently delivering pulses that are of opposite polarity to each other.
2. The method of claim 1 , wherein the step of delivering further involves delivering pulses to a cardiac site to improve heart function as indicated by monitoring one or more of: QRS width, fractionation, late LV activation timing, mechanical synchronicity of free wall and septal wall, and effective throughput/pressure.
3. The method of claim 2 , comprising moving the lead so as to deliver the pulses to different cardiac sites to select a pacing site by monitoring one or more of: QRS width, fractionation, late LV activation timing, mechanical synchronicity of free wall and septal wall, effective throughput/pressure, and by any combination thereof.
4. The method of claim 3 , comprising determining a pacing (voltage) threshold, beyond a capture threshold, to improve heart function as determined by the monitoring.
5. The method of claim 3 , wherein the monitoring comprises monitoring QRS width.
6. The method of claim 2 , wherein the monitoring comprises sensing from a location associated with a left ventricle.
7. The method of claim 6 , wherein the location is within a coronary sinus.
8. The method of claim 1 , wherein the step of delivering at least one pacing profile includes delivering pulses that at least partially overlap in time.
9. The method of claim 1 , wherein the step of delivering at least one pacing profile includes delivering pulses that are substantially identical in time and duration.
10. The method of claim 1 , wherein the first electrode is located at a tip of the lead and wherein the second electrode is located more proximal on the lead than the first electrode and wherein the first and second electrodes are separated by less than about 5-6 mm in distance.
11. The method of claim 1 , wherein said at least one pacing profile includes pulses that are out of phase with one another.
12. The method of claim 1 , wherein said at least one pacing profile includes pulses that do not overlap in time.
13. The method of claim 1 , further including at least one of:
using a pacing voltage threshold to improve heart function relative to a capture at a voltage below the pacing voltage threshold;
delivering pulses of opposite polarity to achieve such heart-function improvement;
bi-ventricular pacing from a lead in the right ventricle for improved heart function;
delivering pulses of opposite polarity at a site near the His bundle;
electrode based His-pacing, without penetrating the myocardium with an electrode used to deliver the pulses of opposite polarity;
generating and/or delivering multiple pacing profiles including a pacing profile that delivers pulses of opposite polarity and another pacing profile;
delivering a pacing profile to generate a synchronous contraction of the septal wall and free wall of the LV from a RV (right-ventricle) pacing location; and
treating one or more of distal LBBB (left bundle branch block) and/or diffuse LBBB by pacing at a site near the His bundle.
14. The method of claim 1 , including using a pacing voltage threshold to improve heart function relative to a capture at a voltage below the pacing voltage threshold.
15. The method of claim 14 , including delivering pulses of opposite polarity to achieve such heart-function improvement.
16. The method of claim 1 , wherein the first and second electrodes are configured without penetrating the myocardium to at least partially concurrently deliver pulses of opposite polarity.
17. The method of claim 1 , comprising synchronizing contraction of a septal wall of the left ventricle and free wall of the left ventricle by the delivering of the at least one pacing profile.
18. The method of claim 1 , comprising delivering the at least one pacing profile in a subject having distal LBBB (left bundle branch block).
19. The method of claim 1 , comprising delivering the at least one pacing profile in a subject having diffuse LBBB (left bundle branch block).
20. The method of claim 1 , comprising adjusting a phase relationship between two electrostimulation pulse phases of opposite polarity delivered to elicit a single biventricular heart contraction, the adjusting based upon information obtained by monitoring one or more of: QRS width, fractionation, late LV activation timing, mechanical synchronicity of free wall and septal wall, effective throughput/pressure, and by any combination thereof.
21. The method of claim 1 , comprising, for eliciting the same heart contraction, also delivering another pacing profile via a lead including at least one electrode located in association with a left ventricle.
22. A method for pacing the left and right ventricles of a heart, the method comprising:
delivering at least one pacing profile, including at least partially concurrent opposite polarity pulses, via a lead including a distal portion located in the right ventricle and including first and second electrodes, wherein the first electrode is located on a septum near a His bundle of a patient and the second electrode is located less than about 5 to 6 millimeters away from the first electrode, to pace the right and left ventricles and resynchronize at least one of the ventricles; and
adjusting the delivering, in response to monitoring one or more of: QRS width, fractionation, late LV activation timing, mechanical synchronicity of free wall and septal wall, and effective throughput/pressure.