Patent EA-003873-B1 (EA)
Title: System and method for multiple site biphasic stimulation to revert ventricular arrhythmias
IPC: A61N1/368
Filed: 1999-03-04
Abstract: 1. A method for biphasic myocardial stimulation, comprising applying multiple site biphasic stimulation which comprises: (a) at least two electrodes administering a first stimulation phase having a first phase polarity, and a second stimulation phase having a second phase polarity, a second phase amplitude is greater than the a phase amplitude after applying two stimulation phases fibrillation is sensed and repeating the above actions if fibrillation is sensed. 2. The method for biphasic myocardial stimulation according to claim 1, wherein the fibrillation is sensed by a sensor. 3. The method for biphasic myocardial stimulation according to claim 1, wherein the first phase amplitude is at a maximum subthreshold amplitude. 4. The method for biphasic myocardial stimulation according to claim 3, where the maximum subthreshold amplitude is about 0.5 volt to about 3.5 volts. 5. The method for biphasic myocardial stimulation according to claim 1, where the first phase shape is ramped from a baseline value to a second value. 6. The method for biphasic myocardial stimulation according to claim 1, where the first phase duration is about one millisecond to about nine milliseconds. 7. The method for biphasic myocardial stimulation according to claim 1, where the second phase amplitude is about two volts to about twenty volts. 8. The method for biphasic myocardial stimulation according to claim 1, where the second phase duration is about 0.2 millisecond to about 1.5 milliseconds. 9. The method for biphasic myocardial stimulation according to claim 1, where the first stimulation phase further comprises a series of stimulating pulses of a predetermined amplitude and duration, and a series of rest periods. 10. The method for biphasic myocardial stimulation according to claim 9, where applying the first stimulation phase further comprises applying a rest period after at least one stimulating pulse. 11. The method for biphasic myocardial stimulation according to claim 9, where the predetermined duration is about 0.2 millisecond to about 1.5 milliseconds. 12. The method for biphasic myocardial stimulation according to claim 9, where the rest period is about 0.2 millisecond to about 1.2 milliseconds. 13. The method for biphasic myocardial stimulation according to claim 1, where the first phase shape is selected from the group consisting of square wave pulse, ramped pulse, and series of short duration square wave pulses. 14. The method for biphasic myocardial stimulation according to claim 1, where at least one of the electrodes is applied to an inner ventricular wall via the vena cava. 15. The method for biphasic myocardial stimulation according to claim 1, where at least one of the electrodes is applied to an exterior ventricular wall. 16. The method for biphasic myocardial stimulation according to claim 5, where the second value is not more than a maximum subthreshold amplitude. 17. The method for biphasic myocardial stimulation according to claim 1, where the stimulation is applied to the electrodes progressively in a manner that mimics the normal flow of electrical depolarization in a heart. 18. The method for biphasic myocardial stimulation according to claim 17, where: the electrodes closest to the A-V node are the first to be fired; the electrodes farthest from the A-V node, following the normal intrinsic conduction paths, are the last to be fired; and the electrodes intermediate between the electrodes closest to the A-V node and the electrodes farthest from the A-V node are fired at an intermediate time that is proportional to their intermediate position, following the normal intrinsic conduction paths. 19. The method for biphasic myocardial stimulation according to claim 18, where the electrodes are ordered by class according to their distance from the A-V node, following the normal intrinsic conduction paths. 20. The method for biphasic myocardial stimulation according to claim 19, where the number of classes is between two and about thirty. 21. A method for reverting ventricular arrhythmias comprising: at least two electrodes administering a first stimulation phase having a positive polarity, a subthreshold amplitude, a duration of about one millisecond to about nine milliseconds, and a shape, wherein the shape is selected from the group consisting of square wave pulse, ramped pulse, and series of short duration square wave pulses; and the at least two electrodes administering a second stimulation phase having a negative polarity, an amplitude of about two volts to about twenty volts, where the second phase amplitude is larger in absolute value than the first phase amplitude. and a duration of about 0.2 millisecond to about 1.5 milliseconds.