| 摘要 |
1. An implantable cardiac stimulator comprising: plural electrodes adapted to applying pacing stimuli to the heart; and pulse generating circuitry connected to the plural electrodes and adapted to generate electrical pulses, wherein a series of pacing stimuli are applied to at least one ventricle having an initial pacing rate, being slightly greater than the intrinsic atrial firing rate, wherein the pacing rate is decreased over time from the initial pacing rate to a minimum pacing rate that is slightly less than the intrinsic atrial firing rate. 2. The cardiac stimulator according to claim 1, further comprising physiological parameter sensor to determine if additional cardiac pacing is needed. 3. The cardiac stimulator according to claim 2, wherein the sensor is adapted to measuring physiological parameters selected from the group consisting of A-V interval, atrial entrainment of left and right ventricles, length of QRS complex, magnitude of QRS complex, arterial blood pressure, venous blood pressure, heart rate, ventricular fibrillation, atrial fibrillation, and probability density function. 4. The cardiac stimulator according to claim 1, wherein said cardiac stimulator is adapted to applying the pacing stimuli and decreasing the pacing rate repeated in a cyclic pattern. 5. The cardiac stimulator according to claim 1, wherein a protocol for decreasing the pacing rate over time is selected from the group consisting of linear, curvilinear, exponential, and combinations thereof. 6. The cardiac stimulator according to claim 5, wherein a protocol for decreasing the pacing rate includes one or more periods of time in which the pacing rate is held constant. 7. The cardiac stimulator according to claim 1, wherein a protocol for decreasing the pacing rate includes one or more periods of time in which the pacing rate is held constant. 8. The cardiac stimulator according to claim 1, wherein the initial pacing rate minus the intrinsic atrial firing rate is greater than the intrinsic atrial firing rate minus the minimum pacing rate. 9. The cardiac stimulator according to claim 1, wherein the initial pacing rate minus the intrinsic atrial firing rate is equal to the intrinsic atrial firing rate minus the minimum pacing rate. 10. The cardiac stimulator according to claim 1, wherein the initial pacing rate minus the intrinsic atrial firing rate is slightly less then the intrinsic atrial firing rate minus the minimum pacing rate. 11. The cardiac stimulator according to claim 1, wherein the pacing stimuli are selected from the group consisting of monophasic stimulation and biphasic stimulation. 12. The cardiac stimulator according to claim 11, wherein the monophasic stimulation is selected from the group consisting of cathodal stimulation and anodal stimulation. 13. The cardiac stimulator according to claim 11, wherein the biphasic stimulation comprises an anodal stimulation phase followed by a cathodal stimulation phase. 14. The cardiac stimulator according to claim 13, wherein the anodal stimulation phase has a magnitude equal to or less than a maximum subthreshold amplitude; and has an approximate shape selected from the group consisting of square wave, increasing ramp, and series of short duration square waves. 15. The cardiac stimulator according to claim 1, wherein the pacing stimuli are applied via multiple electrodes to at least one ventricle. 16. An implantable cardiac stimulator to perform pacing of a heart, the heart having an intrinsic atrial firing rate, the cardiac stimulator comprising: plural electrodes adapted to applying pacing stimuli to the heart; and pulse generating circuitry connected to the plural electrodes and adapted to generate electrical pulses, wherein a series of pacing stimuli are applied to at least one ventricle having an initial pacing rate, the initial pacing rate being slightly greater than the intrinsic atrial firing rate, and wherein the pacing rate is decreased over time from the initial pacing rate to a minimum pacing rate that is slightly less than the intrinsic atrial firing rate. 17. The cardiac stimulator according to claim 16, wherein said cardiac stimulator is adapted to applying the pacing stimuli and decreasing the pacing rate repeated in a cyclic pattern. 18. The cardiac stimulator according to claim 16, wherein a protocol for decreasing the pacing rate over time is selected from the group consisting of linear, curvilinear, exponential, and combinations thereof. 19. The cardiac stimulator according to claim 18, wherein a protocol for decreasing the pacing rate includes one or more periods of time in which the pacing rate is held constant. 20. The cardiac stimulator according to claim 16, wherein a protocol for decreasing the pacing rate includes one or more periods of time in which the pacing rate is held constant. 21. The cardiac stimulator according to claim 16, wherein the initial pacing rate minus the intrinsic atrial firing rate is greater than the intrinsic atrial firing rate minus the minimum pacing rate. 22. The cardiac stimulator according to claim 16, wherein the initial pacing rate minus the intrinsic atrial firing rate is equal to the intrinsic atrial firing rate minus the minimum pacing rate. 23. The cardiac stimulator according to claim 16, wherein the initial pacing rate minus the intrinsic atrial firing rate is slightly less then the intrinsic atrial firing rate minus the minimum pacing rate. 24. The cardiac stimulator according to claim 16, wherein the pacing stimuli are selected from the group consisting of monophasic stimulation and biphasic stimulation. 25. The cardiac stimulator according to claim 24, wherein the monophasic stimulation is selected from the group consisting of cathodal stimulation and anodal stimulation. 26. The cardiac stimulator according to claim 24, wherein the biphasic stimulation comprises an anodal stimulation phase followed by a cathodal stimulation phase. 27. The cardiac stimulator according to claim 26, wherein the anodal stimulation phase has a magnitude equal to or less than a maximum subthreshold amplitude; and has an approximate shape selected from the group consisting of square wave, increasing ramp, and series of short duration square waves. 28. The cardiac stimulator according to claim 16, wherein the pacing stimuli are applied via multiple electrodes to at least one ventricle.
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