Multi-beat integration for cardiac mapping
A non-contact cardiac mapping method is disclosed that includes: (i) inserting a catheter into a heart cavity having an endocardium surface, the catheter including multiple, spatially distributed electrodes; (ii) measuring signals at the catheter electrodes in response to electrical activity in the heart cavity with the catheter spaced from the endocardium surface; and (iii) determining physiological information at multiple locations of the endocardium surface based on the measured signals and positions of the electrodes with respect to the endocardium surface. Related systems and computer programs are also disclosed.
1. A method comprising:
inserting a catheter into a heart cavity having an endocardium surface, the catheter comprising multiple, spatially distributed electrodes;
measuring signals at the catheter electrodes in response to electrical activity in the heart cavity;
integrating information derived from the signals for common phases of the electrical heart beat cycles;
determining physiological information at multiple locations of the endocardium surface based on the measured signals and positions of the electrodes with respect to the endocardium surface; and
displaying at least a portion of the determined physiological information;
wherein the signals are measured during multiple different portions of a heart beat cycle and wherein the physiological information is determined, at least in part, by accounting for changes in the location of the catheter electrodes with respect to the endocardium surface during the multiple different portions of a heart beat cycle.
2. The method of claim 1 , further comprising:
for each of the multiple different portions of a heart beat cycle, determining a position of the catheter electrodes with respect to the endocardium surface and measuring signals at the catheter electrodes in response to electrical activity in the heart cavity,
wherein the determination of the physiological information at the multiple locations of the endocardium surface is based further on the positions of the catheter electrodes and the measured signals at the different catheter positions.
3. The method of claim 1 , wherein accounting for changes in the location of the catheter electrodes with respect to the endocardium surface during the multiple different portions of a heart beat cycle comprises accounting for changes in the shape of the endocardium surface during the multiple different portions of a heart beat cycle.
4. The method of claim 1 , wherein integrating information derived from the signals for common phases of the electrical heart beat cycles comprises separately integrating information derived from the signals for systole and end diastole phases of the heart beat cycle.
5. The method of claim 1 , wherein the determined physiological information includes at least one of:
electrical potential values at the multiple locations of endocardium surface at each of one or more different phases of the heart beat cycle,
a maximum voltage amplitude for one or more heart beat cycles at different ones of the endocardium surface locations,
a frequency representation of electrical activity at multiple locations of the endocardium surface during the heart beat cycle, wherein the frequency representation is computed based on electrical potential values at the multiple locations of endocardium surface at different phases of the heart beat cycle, and
an activation time for each of different locations of the endocardium surface.
6. The method of claim 1 , wherein displaying at least a portion of the determined physiological information comprises displaying separate representations for the endocardium surface at multiple phases in the cardiac cycle.
7. The method of claim 1 wherein determining the physiological information comprises determining the physiological information based at least in part on a mathematical operator approximating Laplace's equation.
8. A method comprising:
inserting multiple catheters into a heart cavity having an endocardium surface, each of the multiple catheters comprising one or more electrodes;
measuring signals at the electrodes on the multiple catheters in response to electrical activity in the heart cavity;
integrating information derived from the signals for common phases of the electrical heart beat cycles;
determining physiological information at multiple locations of the endocardium surface based on the measured signals and positions of the electrodes on the multiple catheters with respect to the endocardium surface; and
displaying at least a portion of the determined physiological information.
9. The method of claim 8 , further comprising:
moving at least one of the multiple catheters to each of multiple, different positions in the heart cavity; and
for each of the different catheter positions, determining the positions of the catheter electrodes with respect to the endocardium surface and measuring signals at the catheter electrodes in response to electrical activity in the heart cavity,
wherein the determination of the physiological information at the multiple locations of the endocardium surface is based further on the positions of the catheter electrodes and the measured signals at the different catheter positions.
10. The method of claim 9 , wherein determination of the physiological information at the multiple locations of the endocardium surface is further based at least in part on a mathematical operator approximating Laplace's equation.
11. The method of claim 8 , wherein integrating information derived from the signals for common phases of the electrical heart beat cycles comprises separately integrating information derived from the signals for systole and end diastole phases of the heart beat cycle.
12. The method of claim 8 , wherein the integrated information comprises integrated electric potentials on the endocardium surface for common phases of the multiple electrical heart cycle.
13. The method of claim 8 , wherein the information derived from the signals for different heart beat cycles comprises a maximum voltage amplitude for each of the different heart beat cycles at different ones of the endocardium surface locations.
14. The method of claim 13 , wherein the combining comprises averaging together the maximum voltage amplitudes for the different heart beat cycles.
15. The method of claim 14 , wherein the averaging is a weighted averaging.
16. The method of claim 8 , wherein the determined physiological information includes at least one of:
electrical potential values at the multiple locations of endocardium surface at each of one or more different phases of the heart beat cycle,
a maximum voltage amplitude for one or more heart beat cycles at different ones of the endocardium surface locations,
a frequency representation of electrical activity at multiple locations of the endocardium surface during the heart beat cycle, wherein the frequency representation is computed based on electrical potential values at the multiple locations of endocardium surface at different phases of the heart beat cycle, and
an activation time for each of different locations of the endocardium surface.
17. The method of claim 16 , wherein displaying at least a portion of the determined physiological information comprises displaying separate representations for the endocardium surface at multiple phases in the cardiac cycle.
18. The method of claim 8 wherein determining the physiological information comprises determining the physiological information based at least in part on a mathematical operator approximating Laplace's equation.
19. A method comprising:
inserting a catheter into a heart cavity having an endocardium surface, the catheter comprising multiple, spatially distributed electrodes and being configured to assume multiple different shapes;
measuring signals at the catheter electrodes in response to electrical activity in the heart cavity with the catheter;
integrating information derived from the signals for common phases of the electrical heart beat cycles;
determining physiological information at multiple locations of the endocardium surface based on the measured signals, positions of the electrodes with respect to the endocardium surface, and a current shape of the catheter; and
displaying at least a portion of the determined physiological information.
20. The method of claim 19 , further comprising:
moving the catheter to each of multiple, different positions in the heart cavity; and
for each of the different catheter positions, determining the positions of the catheter electrodes with respect to the endocardium surface and measuring signals at the catheter electrodes in response to electrical activity in the heart cavity,
wherein the determination of the physiological information at the multiple locations of the endocardium surface is based further on the positions of the catheter electrodes and the measured signals at the different catheter positions.
21. The method of claim 20 , wherein determination of the physiological information at the multiple locations of the endocardium surface is further based at least in part on a mathematical operator approximating Laplace's equation.
22. The method of claim 19 , wherein integrating information derived from the signals for common phases of the electrical heart beat cycles comprises separately integrating information derived from the signals for systole and end diastole phases of the heart beat cycle.
23. The method of claim 19 , wherein the integrated information comprises integrated electric potentials on the endocardium surface for common phases of the multiple electrical heart cycle.
24. The method of claim 19 , wherein the information derived from the signals for different heart beat cycles comprises a maximum voltage amplitude for each of the different heart beat cycles at different ones of the endocardium surface locations.
25. The method of claim 24 , wherein the combining comprises averaging together the maximum voltage amplitudes for the different heart beat cycles.
26. The method of claim 25 , wherein the averaging is a weighted averaging.
27. The method of claim 19 , wherein the determined physiological information includes at least one of:
electrical potential values at the multiple locations of endocardium surface at each of one or more different phases of the heart beat cycle,
a maximum voltage amplitude for one or more heart beat cycles at different ones of the endocardium surface locations,
a frequency representation of electrical activity at multiple locations of the endocardium surface during the heart beat cycle, wherein the frequency representation is computed based on electrical potential values at the multiple locations of endocardium surface at different phases of the heart beat cycle, and
an activation time for each of different locations of the endocardium surface.
28. The method of claim 27 , wherein displaying at least a portion of the determined physiological information comprises displaying separate representations for the endocardium surface at multiple phases in the cardiac cycle.
29. The method of claim 19 wherein determining the physiological information comprises determining the physiological information based at least in part on a mathematical operator approximating Laplace's equation.