Cardiac resynchronization therapy optimization using vector measurements obtained from realtime electrode position tracking
An exemplary method includes selecting a first pair of electrodes to define a first vector and selecting a second pair of electrodes to define a second vector; acquiring position information during one or more cardiac cycles for the first and second pairs of electrodes wherein the acquiring comprises using each of the electrodes for measuring one or more electrical potentials in an electrical localization field established in the patient; and determining a dyssynchrony index by applying a cross-covariance technique to the position information for the first and the second vectors. Another method includes determining a phase shift based on the acquired position information for the first and the second vectors; and determining an interventricular delay based at least in part on the phase shift.
1. A method comprising:
selecting a first pair of electrodes to define a first vector and selecting a second pair of electrodes to define a second vector;
for each of the first and second pairs of electrodes, acquiring coordinate position information at each of a plurality of fiducials within a cardiac cycle, wherein the acquiring comprises establishing an electrical localization field in the patent and using each of the electrodes for measuring one or more electrical potentials in the electrical localization field; and
determining a first vector metric based on the acquired coordinate position information for the first pair of electrodes, and determining a second vector metric based on the acquired coordinate position information for the second pair of electrodes.
2. The method of claim 1 wherein the first and second vector metrics comprise a measure of vector magnitude as a function of time during at least a portion of the cardiac cycle.
3. The method of claim 1 wherein the first and second vector metrics comprise a measure of vector angle as a function of time during at least a portion of the cardiac cycle.
4. The method of claim 2 wherein the measure of vector magnitude comprises a waveform plot of vector magnitude as a function of time.
5. The method of claim 3 wherein the measure of vector angle comprises a waveform plot of vector angles as a function of time.
6. The method of claim 1 wherein each of the first vector and the second vector originates with respect to a first chamber of a heart and terminates with respect to a respective second chamber of the heart different from the first chamber.
7. The method of claim 6 wherein the first chamber is a right atrium.
8. The method of claim 7 wherein the second chamber of the first vector is a right ventricle and the second chamber of the second vector is a left ventricle.
9. The method of claim 6 wherein the first chamber is a right ventricle.
10. The method of claim 9 wherein the second chamber of the first vector is a right atrium and the second chamber of the second vector is a left ventricle.
11. The method of claim 6 wherein the first chamber is a left ventricle.
12. The method of claim 11 wherein the second chamber of the first vector is a right atrium and the second chamber of the second vector is a right ventricle.
13. The method of claim 1 further comprising determining a dyssynchrony index based on the first vector metric and the second vector metric.
14. The method of claim 13 wherein the first and second vector metrics comprise a measure of vector magnitude as a function of time during at least a portion of the cardiac cycle, and determining a dyssynchrony index comprises at least one of:
determining a peak-to-peak value;
determining a maximum; and
determining an average slope.
15. The method of claim 13 wherein the first and second vector metrics comprise a waveform plot of vector magnitude as a function of time during at least a portion of the cardiac cycle, and determining a dyssynchrony index further comprises:
calculating an area under the vector magnitude waveform; and
calculating at least one of a difference between the two areas or a quotient of the two areas.
16. The method of claim 1 wherein the first pair of electrodes and the second pair of electrodes include a same electrode.
17. One or more non-transitory computer-readable storage media comprising processor-executable instructions to configure a computing device to:
select a first pair of electrodes to define a first vector and selecting a second pair of electrodes to define a second vector;
for each of the first and second pairs of electrodes, acquire coordinate position information at each of a plurality of fiducial points within a cardiac cycle, wherein the acquiring comprises establishing an electrical localization field in the patent and using each of the electrodes for measuring one or more electrical potentials in the electrical localization field; and
determine a first vector metric based on the acquired coordinate position information for the first pair of electrodes, and determining a second vector metric based on the acquired coordinate position information for the second pair of electrodes.
18. The media of claim 17 wherein each of the first vector and the second vector originates with respect to a first chamber of a heart and terminates with respect to a respective second chamber of the heart different from the first chamber.