What is claimed is:1. An electrochemical cell comprising a first electrode comprising a first electrode active material and a second electrode electrically associated with the first electrode to provide a first region having a first effective interelectrode surface area between the first and second electrodes and to provide a second, jellyroll region having a second effective interelectrode surface area between the first and second electrodes, and wherein the first region provides the cell dischargeable at a relatively low electrical current of about 1 microampere to about 100 milliamperes corresponding to a C-rate of about C/2,300,000 to about C/23, and wherein the second region provides the cell dischargeable at a relatively high electrical current of about 1 to about 4 amperes corresponding to a C-rate of about C/2.3 to about C/0.575.2. The electrochemical cell of claim 1 wherein the first region contributes greater than 10% of the total energy density provided by the second electrode and the first region has less than 50% of the total surface area provided by the second electrode.3. The electrochemical cell of claim 1 wherein the first electrode is the anode and the second electrode is the cathode.4. The electrochemical cell of claim 1 wherein the portion of the second electrode providing the first region has greater than 10% of the total energy density provided by the second electrode but less than 30% of the total surface area.5. The electrochemical cell of claim 1 including a conductive casing serving as a terminal for the first electrode and wherein the first region of the second electrode is connected to a first terminal lead and the second region of the second electrode is connected to a second terminal lead.6. The electrochemical cell of claim 1 wherein the first region and the second region each contribute about 50% of the total cell capacity and a ratio of the capacity (Qa) of the first electrode to the capacity (Qc) of the second electrode is greater than about 0.75:1.0.7. The electrochemical cell of claim 1 wherein a capacity ratio of the first region to the second region is about 0.5:0.5.8. The electrochemical cell of claim 7 wherein a ratio of the capacity of the first electrode to the capacity of the first region of the second electrode is about 1.1:1.0 and a ratio of the capacity of the first electrode to the capacity of the second region of the second electrode is about 0.4:1.0, and wherein a ratio of the total capacity of the first electrode to the total capacity of the second electrode is about 0.75:1.0.9. The electrochemical cell of claim 1 wherein a capacity ratio of the first region to the second region is about 0.6:0.4.10. The electrochemical cell of claim 9 wherein a ratio of the capacity of the first electrode to the capacity of the first region of the second electrode is about 1.1:1.0 and a ratio of the capacity of the first electrode to the capacity of the second region of the second electrode is about 0.4:1.0, and wherein a ratio of the total capacity of the first electrode to the total capacity of the second electrode is about 0.82:1.0.11. The electrochemical cell of claim 1 wherein a capacity ratio of the first region to the second region is about 1.1:1.0 to about 0.8:1.0.12. The electrochemical cell of claim 1 wherein the first region is provided by at least one structure of a second electrode active material of the second electrode and wherein the second region of the second electrode is provided by at least one structure of a third electrode active material.13. The electrochemical cell of claim 12 wherein the second and third electrode active materials are the same.14. The electrochemical cell of claim 12 wherein the second and third electrode active materials are dissimilar.15. The electrochemical cell of claim 1 wherein the first electrode is associated with the second region of the second electrode in a jellyroll wound configuration and wherein the first electrode is associated with the first region of the second electrode in a face-to-face, prismatic relationship.16. The electrochemical cell of claim 15 wherein at least one second electrode structure comprising the first region is disposed in a face-to-face, prismatic position centered in the jellyroll wound configuration of the first electrode and the second region of the second electrode and wherein at least one second electrode structure comprising the first region is associated with the first electrode in a face-to-face, prismatic relationship spaced outwardly farther than the second region of the second electrode associated with the first electrode in the jellyroll wound configuration.17. An electrochemical cell capable of delivering electrical current in a first range of currents and which is independently and simultaneously capable of delivering electrical current in a second range of currents greater than the first range and wherein the second range of electrical current is provided by a portion of the electrodes comprising the cell disposed in a jellyroll configuration.18. The electrochemical cell of claim 17 wherein the first range of currents is about 1 microampere to about 100 milliamperes corresponding to a C-rate of about C/2,300,000 to about C/23, and wherein the second range of current is about 1 ampere to about 4 amperes corresponding to a C-rate of about C/2.3 to about C/0.575.19. In combination with an implantable medical device requiring electrical power for a monitoring function and for a device operating function, an electrochemical cell which is capable of providing an electrical current of about 1 microamperes to about 100 milliamperes corresponding to a C-rate of about C/2,300,000 to about C/23 for the monitoring function, and wherein the electrochemical cell is independently and simultaneously capable of delivering electrical pulse currents of about 1 ampere to about 4 amperes corresponding to a C-rate of about C/2.3 to about C/0.575 for the device operating function and wherein the electrical pulse currents for the device operating function are provided by a portion of the electrodes of the electrochemical cell disposed in a jellyroll configuration.20. In combination with an implantable medical device requiring electrical power for a monitoring function and a device operating function, an electrochemical cell comprising:a) a medium rate, constant dischargeable or constant drain electrochemical couple for providing low level currents for the monitoring function;b) a high rate, pulse dischargeable electrochemical couple provided in a jellyroll configuration for providing high level current for the operating function; andc) a single casing means containing both couples wherein the medium rate, constant drain couple and the high rate, pulse dischargeable couple share the same anode.21. The combination of claim 20 wherein the casing has a prismatic shape.