Implantable pacemaker including means and method of terminating a pacemaker-mediated tachycardia during rate adaptive pacing
First Claim
1. An implantable pacemaker including means for terminating a pacemaker-mediated tachycardia (PMT) comprising:
- detection means within said implantable pacemaker for detecting heart rate and for detecting P-waves and V-pulses and for detecting a prescribed sequence of cardiac cycles, each cardiac cycle of said prescribed sequence comprising a P-wave followed by a V-pulse, the time interval between said P-wave and said V-pulse of each cardiac cycle comprising a P-V interval (PVI), a time interval between successive V-pulses comprising a V-V interval, the detection means further comprising means for timing a timed atrial pulse from a detected P-wave occurring in a corresponding one of the cycles in the sequence of cardiac cycles; and
stimulation means responsive to the detection means for stimulating the atrium by said timed atrial pulse for terminating a PMT.
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Accused Products
Abstract
An atrial tracking dual-chamber pacemaker and method of use thereof for terminating a pacemaker-mediated tachycardia (PMT). The pacemaker includes means for determining whether the present heart rate exceeds a tachycardia reference rate, and if so, whether a PMT-indicating sequence of a tracked P-wave, including a retrograde P-wave followed by a V-pulse, occurs repetitiously for at least a predetermined number of cardiac cycles. The pacemaker includes means for measuring the interval between a P-wave and a V-pulse (PVI) and sets the PVI to 250 milliseconds when the measured value is less than 250 milliseconds. The pacemaker issues a PMT-terminating timed atrial pulse which is timed from a retrograde P-wave by a time equal to the PVI, plus a delay of about 25-100 milliseconds. In the event the atrial pulse fails to terminate the PMT, the process is repeated after a fixed number of cardiac cycles has occurred. An alternate embodiment includes determining a ventricular escape interval (VEI) which is equal to the AEI plus the PVI. Upon the delivery of the timed atrial pulse, the pacemaker changes to the VDD mode of operation, and immediately upon the occurrence of the following V-pulse which is a VEI displaced from the prior pulse, the pacemaker reverts to the DDD mode of operation.
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Citations
42 Claims
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1. An implantable pacemaker including means for terminating a pacemaker-mediated tachycardia (PMT) comprising:
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detection means within said implantable pacemaker for detecting heart rate and for detecting P-waves and V-pulses and for detecting a prescribed sequence of cardiac cycles, each cardiac cycle of said prescribed sequence comprising a P-wave followed by a V-pulse, the time interval between said P-wave and said V-pulse of each cardiac cycle comprising a P-V interval (PVI), a time interval between successive V-pulses comprising a V-V interval, the detection means further comprising means for timing a timed atrial pulse from a detected P-wave occurring in a corresponding one of the cycles in the sequence of cardiac cycles; and stimulation means responsive to the detection means for stimulating the atrium by said timed atrial pulse for terminating a PMT. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An implantable pacemaker for terminating a pacemaker-mediated tachycardia (PMT) in a patient comprising:
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detection means within the implantable pacemaker for detecting P-waves and V-pulses, the P-waves including retrograde P-waves, and for detecting a prescribed sequence of cardiac cycles, each cardiac cycle of the prescribed sequence comprising a P-wave followed by a V-pulse, the time interval between the P-wave and the V-pulse of each cardiac cycle comprising a P-V interval (PVI), said PVI also being adjustable to at least an original value and a prescribed value, the time interval between successive V-pulses comprising a V-V interval, said detection means further comprising means for timing a timed atrial pulse from a detected retrograde P-wave occurring in the sequence of cardiac cycles; means for determining the duration of the PVI and for adjusting the PVI to the prescribed value when the PVI is less than the prescribed value; and stimulation means responsive to the detection means for stimulating the atrium by said timed atrial pulse for terminating a PMT. - View Dependent Claims (14, 15, 16, 17, 18)
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19. An implantable pacemaker for terminating a pacemaker-mediated tachycardia (PMT) in a patient, wherein the pacemaker includes DDD and VDD modes of operation, the pacemaker comprising:
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detection means within the implantable pacemaker for detecting P-waves and V-pulses, the P-waves including retrograde P-waves and for detecting a prescribed sequence of cardiac cycles, each cardiac cycle of the prescribed sequence comprising a P-wave followed by a V-pulse, the time interval between the P-wave and the V-pulse of each cardiac cycle comprising a P-V interval (PVI), the time interval between successive V-pulses comprising a V-V interval, the time interval between successive V-V pulses with an A-pulse therebetween comprising a VEI interval, the time interval between a V-pulse and the following retrograde P-wave comprising an atrial escape interval (AEI); the prescribed sequence of cardiac cycles includes at least four cycles comprising a first, a second, a third and a fourth cycle, the four cycles occurring successively, wherein the detection means measures the V-V interval in the first and second cycles for comparison to a tachycardia recognition rate (TRR), and further measures the PVI in the second cycle for comparison to a prescribed value; and stimulation means responsive to the detection means for stimulating the atrium by said timed atrial pulse, for terminating a PMT. - View Dependent Claims (20, 21, 22, 23, 24)
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25. An implantable pacemaker for terminating a pacemaker-mediated tachycardia (PMT) in a patient comprising:
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detection means within the implantable pacemaker for detecting P-waves and V-pulses, the P-waves including retrograde P-waves, and for detecting a prescribed sequence of cardiac cycles, each cardiac cycle of the prescribed sequence comprising a P-wave followed by a V-pulse, the time interval between the P-wave and the V-pulse of each cardiac cycle comprising a P-V interval (PVI), the time interval between successive V-pulses comprising a V-V interval, the time interval between successive V-V pulses with an A-pulse therebetween comprising a VEI interval, the time interval between a V-pulse and the following retrograde P-wave comprising an atrial escape interval (AEI), the detection means further comprising means for timing a timed atrial pulse from a detected retrograde P-wave occurring in the sequence of cardiac cycles and for detecting the value of the AEI and the PVI in one cycle of the sequence of cardiac cycles and for timing a timed atrial pulse from a retrograde P-wave occurring in another one of the cycles in the sequence, and stimulation means responsive to the detection means for stimulating the atrium by said timed atrial pulse in still another one of the cycles in the sequence for terminating a PMT.
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26. A method for terminating a PMT in a patient having an implanted pacemaker, said method comprising the steps of:
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(a) sensing a V-pulse followed by a P-wave in a plurality of successive cardiac cycles to thereby sense an atrial escape interval AEI; (b) sensing a P-wave followed by a V-pulse in a plurality of successive cardiac cycles to thereby sense a PVI; (c) sensing a first V-pulse followed by a second V-pulse in a plurality of successive cardiac cycles to thereby sense a V-V interval, the V-V interval comprising the elapsed time between the first V-pulse and the second V-pulse; (d) sensing if the plurality of successive cardiac cycles sensed in step (c) occurs at a rate in excess of a tachycardia reference rate (TRR); (e) sensing if the sequence of a P-wave followed by a V-pulse sensed in step (b) or a V-pulse followed by a P-wave sensed in step (a) continues repetitiously for a prescribed number of sequences; (f) sensing if the number of V-V intervals exceeds a prescribed number wherein the rate sensed in step (d) exceeds the TRR and wherein the sequence of P-waves and V-pulses sensed in step (e) continues repetitiously; (g) sensing if the PVI is less than a prescribed value and adjusting the PVI to the prescribed value when the PVI is less than the prescribed value; (h) stimulating the atrium with an atrial pulse timed from a P-wave, a prescribed delay, the delay comprising the PVI of step (g) plus a delay interval, the delay interval comprising a range of approximately 25-100 milliseconds. - View Dependent Claims (27, 28, 29, 30, 31, 32, 33, 34)
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35. An implantable pacemaker including means for terminating a pacemaker-mediated tachycardia (PMT) comprising:
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detection means within said implantable pacemaker for detecting heart rate and for detecting P-waves and V-pulses and for detecting a prescribed sequence of cardiac cycles, each cardiac cycle of said prescribed sequence comprising a P-wave followed by a V-pulse, the time interval between said P-wave and said V-pulse of each cardiac cycle comprising a P-V interval (PVI), a time interval between successive V-pulses comprising a V-V interval, the detection means further comprises means for timing a timed atrial pulse from a detected P-wave occurring in a corresponding one of the cycles in the sequence of cardiac cycles; and stimulation means responsive to the detection means for stimulating the atrium by said timed atrial pulse for terminating a PMT when the heart rate exceeds approximately 100 pulses per minute.
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36. An implantable pacemaker including means for terminating a pacemaker-mediated tachycardia (PMT) comprising:
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detection means within said implantable pacemaker for detecting heart rate and for detecting P-waves and V-pulses and for detecting a prescribed sequence of cardiac cycles, each cardiac cycle of said prescribed sequence comprising a P-wave followed by a V-pulse, the time interval between said P-wave and said V-pulse of each cardiac cycle comprising a P-V interval (PVI), a time interval between successive V-pulses comprising a V-V interval, the detection means further comprises means for timing a timed atrial pulse from a detected P-wave occurring in a corresponding one of the cycles in the sequence of cardiac cycles; and stimulation means responsive to the detection means for stimulating the atrium by said timed atrial pulse for terminating a PMT when the number of successive V-V intervals in the sequence of cardiac cycles comprises a number ranging from 2-20.
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37. An implantable pacemaker for terminating a pacemaker-mediated tachycardia (PMT) in a patient comprising:
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detection means within the implantable pacemaker for detecting P-waves and V-pulses, the P-waves including retrograde P-waves, and for detecting a prescribed sequence of cardiac cycles, each cardiac cycle of the prescribed sequence comprising a P-wave followed by a V-pulse, the time interval between the P-wave and the V-pulse of each cardiac cycle comprising a P-V interval (PVI), said PVI also being adjustable to at least a first prescribed value and a second prescribed value, the time interval between successive V-pulses comprising a V-V interval; means for timing a timed atrial pulse a prescribed delay from a detected P-wave occurring in the sequence of cardiac cycles; means for determining the duration of the PVI and for adjusting the PVI to the first prescribed value when the PVI is less than the first prescribed value; and stimulation means responsive to the detection means for stimulating the atrium by atrial pulses, such atrial pulses comprising at least said timed atrial pulse, the time interval between a V-pulse followed by the atrial pulse which immediately follows the timed atrial pulse comprising an atrial escape interval (AEI), said AEI also being adjustable to a third prescribed value, and means for adjusting the PVI to the second prescribed value and for adjusting the AEI to the third prescribed value for maintaining the V-V interval. - View Dependent Claims (38, 39, 40, 41, 42)
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Specification