US5690689A — Dual-chamber implantable stimulation device havin…

Claim 1

Independent Claim 149 words

A method of treating cardiomyopathy using an implanted dual-chamber pacemaker to provide preemptive ventricular pacing, the pacemaker having an atrial channel and a ventricular channel, means for sensing atrial activity in the atrial channel and natural ventricular activity (an R-wave) in the ventricular channel, a pulse generator that generates a ventricular stimulation pulse (V-pulse) in the ventricular channel at the conclusion of an AV/PV interval that commences with atrial activity and is reset with a sensed R-wave, said method comprising: (a) measuring a natural conduction time interval as the elapsed time between atrial activity and an R-wave in a given cardiac cycle; (b) automatically setting the AV/PV interval of the pacemaker to a prescribed amount less than the natural conduction time determined in step (a); and (c) generating the V-pulse at the conclusion of the AV/PV interval to preemptively stimulate the ventricular channel before natural ventricular activity can occur.

Claim 2

Independent Claim 149 words

A method of treating cardiomyopathy using an implanted dual-chamber pacemaker to provide preemptive ventricular pacing, the pacemaker having an atrial channel and a ventricular channel, means for sensing atrial activity in the atrial channel and natural ventricular activity (an R-wave) in the ventricular channel, a pulse generator that generates a ventricular stimulation pulse (V-pulse) in the ventricular channel at the conclusion of an AV/PV interval that commences with atrial activity and is reset with a sensed R-wave, said method comprising: (a) measuring a natural conduction time interval as the elapsed time between atrial activity and an R-wave in a given cardiac cycle; (b) automatically setting the AV/PV interval of the pacemaker to a prescribed amount less than the natural conduction time determined in step (a); and (c) generating the V-pulse at the conclusion of the AV/PV interval to preemptively stimulate the ventricular channel before natural ventricular activity can occur.

Claim 3

Dependent Claim 29 words

The method of claim 1, wherein step (a) comprises periodically measuring the natural conduction time interval every x cardiac cycles, where x is an integer between 10 and 2048.

Claim 4

Dependent Claim 38 words

The method of claim 1, wherein step (a) comprises measuring the natural conduction time interval for y consecutive cardiac cycles and computing an average of the natural conduction time interval measurements thus made, where y is an integer.

Claim 5

Dependent Claim 30 words

The method of claim 1, wherein step (b) comprises setting the AV/PV interval of the pacemaker to a value that is from 1-100 msec less than the natural conduction time.

Claim 6

Dependent Claim 37 words

The method of claim 1, wherein step (c) comprises applying the V-pulse through the ventricular channel to a ventricular location adapted to create a mechanical contraction sequence different from the contraction sequence resulting from natural ventricular activity.

Claim 7

Independent Claim 191 words

A method of operating a dual-chamber implantable pacemaker in order to maximize cardiac output of a patient by pacing in the ventricle, if needed, at a time in a cardiac cycle that is near the patient's natural conduction time, the pacemaker having a PV/AV interval that defines the maximum time permitted by the pacemaker after atrial activity before a ventricular stimulation pulse (V-pulse) is generated, comprising: (a) measuring a PR/AR interval as the time interval between atrial activity and a natural ventricular depolarization (R-wave), where atrial activity comprises either a natural atrial depolarization (P-wave) or an atrial stimulation pulse (A-pulse), whichever occurs first in a given cardiac cycle; (b) setting the PV/AV interval of the pacemaker to be equal to the measured PR/AR interval ±Δ, where Δ is a prescribed time increment; and (c) repeating steps (a) and (b) in accordance with a prescribed schedule so that the PV/AV interval of the pacemaker tracks the measured PR/AR interval within ±Δ, and so that a V-pulse is generated and applied to the patient's ventricle at the conclusion of the PV/AV interval in each cardiac cycle in which an R-wave does not occur.

Claim 8

Independent Claim 191 words

A method of operating a dual-chamber implantable pacemaker in order to maximize cardiac output of a patient by pacing in the ventricle, if needed, at a time in a cardiac cycle that is near the patient's natural conduction time, the pacemaker having a PV/AV interval that defines the maximum time permitted by the pacemaker after atrial activity before a ventricular stimulation pulse (V-pulse) is generated, comprising: (a) measuring a PR/AR interval as the time interval between atrial activity and a natural ventricular depolarization (R-wave), where atrial activity comprises either a natural atrial depolarization (P-wave) or an atrial stimulation pulse (A-pulse), whichever occurs first in a given cardiac cycle; (b) setting the PV/AV interval of the pacemaker to be equal to the measured PR/AR interval ±Δ, where Δ is a prescribed time increment; and (c) repeating steps (a) and (b) in accordance with a prescribed schedule so that the PV/AV interval of the pacemaker tracks the measured PR/AR interval within ±Δ, and so that a V-pulse is generated and applied to the patient's ventricle at the conclusion of the PV/AV interval in each cardiac cycle in which an R-wave does not occur.

Claim 9

Dependent Claim 33 words

The method of claim 6, wherein the prescribed schedule of step (c) comprises periodically measuring the natural conduction time interval every x cardiac cycles, where x is an integer between 10 and 2048.

Claim 10

Dependent Claim 28 words

The method of claim 6 wherein the prescribed schedule of step (c) comprises periodically measuring the natural conduction time interval every k seconds, where k is an integer.

Claim 11

Dependent Claim 12 words

The method of claim 8, wherein k is at least 30 seconds.

Claim 12

Dependent Claim 64 words

The method of claim 6, wherein the prescribed schedule of step (c) comprises measuring the natural conduction time interval whenever either: (1) n consecutive cardiac cycles occur without an R-wave being sensed, where n is a first prescribed integer; or (2) m consecutive cardiac cycles occur with an R-wave being sensed in each cycle, where m is a second prescribed integer, whichever occurs first.

Claim 13

Dependent Claim 13 words

The method of claim 10, wherein n and m are at least five.

Claim 14

Independent Claim 130 words

A method of treating cardiomyopathy using an implanted dual-chamber pacemaker, the pacemaker having means for sensing atrial and ventricular events, and means for generating a ventricular stimulation pulse (V-pulse) and delivering the V-pulse to a prescribed ventricular location, said method comprising: (a) determining a natural conduction time as the difference between an atrial event and a natural ventricular event within a given cardiac cycle; and (b) generating and delivering the V-pulse to the prescribed ventricular location at a time, following an atrial event in each cardiac cycle, that is less than the natural conduction time determined in step (a), whereby the V-pulse preempts a natural ventricular event in the presence of a substantially constant natural conduction time, the V-pulse thus delivered triggering a mechanical contraction sequence that improves cardiac output.

Claim 15

Independent Claim 130 words

A method of treating cardiomyopathy using an implanted dual-chamber pacemaker, the pacemaker having means for sensing atrial and ventricular events, and means for generating a ventricular stimulation pulse (V-pulse) and delivering the V-pulse to a prescribed ventricular location, said method comprising: (a) determining a natural conduction time as the difference between an atrial event and a natural ventricular event within a given cardiac cycle; and (b) generating and delivering the V-pulse to the prescribed ventricular location at a time, following an atrial event in each cardiac cycle, that is less than the natural conduction time determined in step (a), whereby the V-pulse preempts a natural ventricular event in the presence of a substantially constant natural conduction time, the V-pulse thus delivered triggering a mechanical contraction sequence that improves cardiac output.

Claim 16

Dependent Claim 40 words

The method of claim 12, further including repeating step (a) pursuant to a prescribed schedule so that in the presence of a changing natural conduction time, preemptive ventricular pacing continues to trigger the mechanical contraction sequence that improves cardiac output.

Claim 17

Dependent Claim 43 words

The method of claim 12, wherein step (b) includes delivering the V-pulse to the prescribed ventricular location at a time in the cardiac cycle that is less than the natural conduction time by an amount Δ, where Δ is 1 to 100 msec.

Claim 18

Dependent Claim 43 words

The method of claim 14 wherein the step of determining the natural conduction time comprises measuring the natural conduction time for y consecutive cardiac cycles, where y is an integer, and computing an average of the natural conduction time interval measurements thus made.

Claim 19

Independent Claim 117 words

A method of treating a patient's heart suffering from cardiomyopathy, comprising: (a) monitoring a plurality of cardiac cycles of the patient's heart to determine a natural conduction time, where the natural conduction time commences with an atrial event and terminates with a natural ventricular event within a given cardiac cycle; and (b) applying an electrical stimulus to a prescribed ventricular location at a time, following an atrial event in each cardiac cycle, that is less than the natural conduction time determined in step (a), whereby the electrical stimulus preempts a natural ventricular event in the presence of a substantially constant natural conduction time, the electrical stimulus thus delivered triggering a mechanical contraction sequence that improves cardiac output.

Claim 20

Independent Claim 117 words

A method of treating a patient's heart suffering from cardiomyopathy, comprising: (a) monitoring a plurality of cardiac cycles of the patient's heart to determine a natural conduction time, where the natural conduction time commences with an atrial event and terminates with a natural ventricular event within a given cardiac cycle; and (b) applying an electrical stimulus to a prescribed ventricular location at a time, following an atrial event in each cardiac cycle, that is less than the natural conduction time determined in step (a), whereby the electrical stimulus preempts a natural ventricular event in the presence of a substantially constant natural conduction time, the electrical stimulus thus delivered triggering a mechanical contraction sequence that improves cardiac output.

Claim 21

Dependent Claim 53 words

The method of claim 16, further including applying the electrical stimulus to the prescribed ventricular location at a time in the cardiac cycle that is 1 to 100 msec before the termination of the natural conduction time, and hence 1 to 100 msec before a natural ventricular event occurs in the cardiac cycle.

Claim 22

Dependent Claim 41 words

The method of claim 17, further including applying the electrical stimulus to a ventricular location adapted to cause a mechanical contraction sequence of the heart that differs from a natural contraction sequence of the type that follows a natural ventricular event.

Claim 23

Dependent Claim 219 words

A dual-chamber pacemaker for controlling ventricular pacing in order to increase cardiac output in a patient suffering from cardiomyopathy by preemptively stimulating a ventricle of the patient's heart, comprising: an atrial lead having an electrode in contact with one of the atria of the heart, and a ventricular lead having an electrode in contact with one of the ventricles of the heart; means for sensing a natural conduction time interval of the patient through the electrodes of the atrial and ventricular leads, the natural conduction time interval comprising the time interval between atrial activity, whether sensed or paced, and a natural ventricular depolarization (R-wave); pulse generator means for generating a ventricular stimulation pulse (V-pulse) upon the timing out of an AV time interval and applying the V-pulse to the electrode of the ventricular lead; and timing means, coupled to the pulse generator means, for defining the AV time interval to begin with atrial activity, and for setting the AV time interval to a value that, for ventricular pacing, is always less than the natural conduction time interval by a prescribed amount; whereby the V-pulse is generated by the pulse generator means and applied to one of the ventricles of the heart prior to the occurrence of natural ventricular activity for preemptively stimulating the ventricle to thereby increase cardiac output.

Claim 24

Dependent Claim 219 words

A dual-chamber pacemaker for controlling ventricular pacing in order to increase cardiac output in a patient suffering from cardiomyopathy by preemptively stimulating a ventricle of the patient's heart, comprising: an atrial lead having an electrode in contact with one of the atria of the heart, and a ventricular lead having an electrode in contact with one of the ventricles of the heart; means for sensing a natural conduction time interval of the patient through the electrodes of the atrial and ventricular leads, the natural conduction time interval comprising the time interval between atrial activity, whether sensed or paced, and a natural ventricular depolarization (R-wave); pulse generator means for generating a ventricular stimulation pulse (V-pulse) upon the timing out of an AV time interval and applying the V-pulse to the electrode of the ventricular lead; and timing means, coupled to the pulse generator means, for defining the AV time interval to begin with atrial activity, and for setting the AV time interval to a value that, for ventricular pacing, is always less than the natural conduction time interval by a prescribed amount; whereby the V-pulse is generated by the pulse generator means and applied to one of the ventricles of the heart prior to the occurrence of natural ventricular activity for preemptively stimulating the ventricle to thereby increase cardiac output.

Claim 25

Independent Claim 108 words

A method of treating cardiomyopathy using an implanted dual-chamber pacemaker, the pacemaker including means for sensing atrial and ventricular events, means for generating a ventricular stimulation pulse (V-pulse), and means for delivering the V-pulse to an apex of the ventricle, said method comprising: measuring a natural conduction time as the difference between an atrial event and a natural ventricular event within a given cardiac cycle; and generating and delivering the V-pulse to the ventricular apex at a time that is less than the measured natural conduction time; whereby the V-pulse preempts a natural ventricular event, the V-pulse thereby triggering an apical mechanical contraction sequence that improves cardiac output.

Claim 26

Independent Claim 108 words

A method of treating cardiomyopathy using an implanted dual-chamber pacemaker, the pacemaker including means for sensing atrial and ventricular events, means for generating a ventricular stimulation pulse (V-pulse), and means for delivering the V-pulse to an apex of the ventricle, said method comprising: measuring a natural conduction time as the difference between an atrial event and a natural ventricular event within a given cardiac cycle; and generating and delivering the V-pulse to the ventricular apex at a time that is less than the measured natural conduction time; whereby the V-pulse preempts a natural ventricular event, the V-pulse thereby triggering an apical mechanical contraction sequence that improves cardiac output.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-11-24	2001-05-26	2001-11-25	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-11-24	2005-05-26	2005-11-25	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-11-24	2009-05-26	2009-11-25	$7700.00	Window Closed / Lapsed

Dual-chamber implantable stimulation device having adaptive AV intervall and method for treating cardiomyopathy thereof

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