Pacemaker mediated tachycardia response for VDD and VDDR modalities
First Claim
1. In a patient having an implanted pacemaker, a method for detecting and suppressing a pacemaker mediated tachycardia (PMT), the pacemaker including:
- sensing means for sensing P-waves;
pulse generation means for generating a V-pulse; and
timing means for defining a PV delay that begins upon sensing a P-wave, after which a V-pulse is generated, whereby sensed P-waves are tracked with a V-pulse that occurs one PV delay thereafter, and a post ventricular atrial refractory period (PVARP) that begins following a V-pulse, and during which P-waves are not tracked, said method comprising the steps of;
detecting a PMT; and
suppressing the PMT in response to the detecting of the PMT, by;
increasing the PVARP of the pacemaker from an initial PVARP to an extended PVARP;
sensing if a P-wave occurs following the extended PVARP within at least one of a plurality of subsequent cardiac cycles; and
maintaining the PVARP at the extended PVARP in the absence of a P-wave being sensed following the extended PVARP;
restoring the PVARP to its initial PVARP in response to a P-wave being sensed following the extended PVARP within the at least one of the plurality of subsequent cardiac cycles.
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Accused Products
Abstract
A pacemaker mediated tachycardia (PMT) is detected and suppressed in an implantable pacemaker operating in the VDD or VDDR modality. Such suppression is effectuated by extending the post ventricular atrial refractory period (PVARP) of the pacemaker to an extended PVARP that prevents retrograde P-waves from being tracked, thereby suppressing the PMT. The extended PVARP includes a retrograde window portion, following an absolute refractory portion. P-waves that occur during the retrograde window portion of the extended PVARP are deemed to be retrograde P-waves. The extended PVARP is returned to its original value whenever: (1) a P-wave is sensed following the extended PVARP, which P-wave is deemed to be a sinus P-wave, or (2) whenever a sufficient number of cardiac cycles elapse without the occurrence of a retrograde P-wave.
53 Citations
24 Claims
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1. In a patient having an implanted pacemaker, a method for detecting and suppressing a pacemaker mediated tachycardia (PMT), the pacemaker including:
- sensing means for sensing P-waves;
pulse generation means for generating a V-pulse; and
timing means for defining a PV delay that begins upon sensing a P-wave, after which a V-pulse is generated, whereby sensed P-waves are tracked with a V-pulse that occurs one PV delay thereafter, and a post ventricular atrial refractory period (PVARP) that begins following a V-pulse, and during which P-waves are not tracked, said method comprising the steps of;detecting a PMT; and suppressing the PMT in response to the detecting of the PMT, by; increasing the PVARP of the pacemaker from an initial PVARP to an extended PVARP; sensing if a P-wave occurs following the extended PVARP within at least one of a plurality of subsequent cardiac cycles; and maintaining the PVARP at the extended PVARP in the absence of a P-wave being sensed following the extended PVARP; restoring the PVARP to its initial PVARP in response to a P-wave being sensed following the extended PVARP within the at least one of the plurality of subsequent cardiac cycles. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- sensing means for sensing P-waves;
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8. In a patient having an implanted dual chamber pacemaker, a method for detecting and suppressing a pacemaker mediated tachycardia (PMT), the pacemaker including:
- sensing means for sensing P-waves;
pulse generation means for generating a V-pulse; and
timing means for defining a PV delay that begins upon sensing a P-wave, after which a V-pulse is generated, whereby sensed P-waves are tracked by generating a V-pulse one PV delay thereafter, and a post ventricular atrial refractory period (PVARP) that begins following a V-pulse, and during which P-waves are not tracked, said method comprising the steps of;determining if a PMT is present; and suppressing the PMT by; extending the PVARP of the pacemaker from an initial value to an extended value, whereby an extended PVARP is generated; sensing the occurrence of a P-wave;
maintaining the PVARP at the extended PVARP in the absence of a P-wave being sensed following the extended PVARP;restoring the PVARP to its initial value if;
(1) a P-wave is sensed following the extended PVARP within at least one of the plurality of subsequent cardiac cycles, or (2) a prescribed number of subsequent cardiac cycles elapse without a P-wave being sensed during the extended PVARP, whichever occurs first. - View Dependent Claims (9, 10, 11, 12, 13)
- sensing means for sensing P-waves;
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14. In a pacemaker having sensing and timing circuits, a method for detecting and suppressing a pacemaker mediated tachycardia (PMT), said method comprising the steps of:
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detecting a PMT using the sensing and timing circuits of the pacemaker; and suppressing the PMT once detected by; increasing a post ventricular atrial refractory period (PVARP) of the pacemaker from an initial value to an extended PVARP; sensing a P-wave during the extended PVARP within at least one of a plurality of subsequent cardiac cycles; resetting a no-sensed-P-event (NSPE) count in response to the sensing of a P-wave during the extended PVARP within the at least one of the plurality of subsequent cardiac cycles; incrementing the NSPE count in response to an extended PVARP interval, within the plurality of subsequent cardiac cycles, during which a P-wave is not sensed; determining whether the NSPE count reaches a predefined terminal count; restoring the PVARP to its initial value in response to determining that the NSPE count has reached the terminal count. - View Dependent Claims (15, 16, 17, 18)
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19. An implantable dual-chamber pacemaker for detecting and suppressing a pacemaker mediated tachycardia (PMT) comprising:
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detecting means for detecting a PMT; and suppressing means for suppressing the PMT once detected, the suppressing means including; PVARP extension means responsive to the PMT detecting means for extending a post ventricular atrial refractory period (PVARP) of the pacemaker from an initial value to an extended value, thereby creating an extended PVARP; first sensing means for sensing a P-wave following the extended PVARP within at least one of a plurality of subsequent cardiac cycles; and maintaining means for maintaining the PVARP at the extended PVARP in the absence of a P-wave being sensed following the extended PVARP; restoring means for restoring the PVARP to its initial value in response to a P-wave being sensed by the first sensing means; whereby a PMT is detected, suppressed and the PVARP is restored to its initial value. - View Dependent Claims (20, 21, 22)
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23. An implantable pacemaker for detecting and suppressing a pacemaker mediated tachycardia (PMT), said pacemaker comprising:
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detecting means for detecting a PMT; and PMT suppressing means responsive to the detecting means for suppressing the PMT, the PMT suppressing means including; extension means for increasing a PVARP of the pacemaker from an initial value to an extended value, thereby creating an extended PVARP; sensing means for sensing a P-wave during the extended PVARP within at least one of a plurality of subsequent cardiac cycles; an incrementable counter coupled to the sensing means, the counter being incremented in response to an extended PVARP interval, within the plurality of subsequent cardiac cycles, during which a P-wave is not sensed by the sensing means; reset means coupled to the counter for resetting the counter in response to the sensing of a P-wave during the extended PVARP within the at least one of the plurality of subsequent cardiac cycles; processing means coupled to the counter and reset means for determining whether the counter reaches a terminal count; restoring means for restoring the PVARP to its initial value in response to the processor means determining that the counter has reached a terminal count. - View Dependent Claims (24)
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Specification