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WO1995009661A2 - Procede et appareil preferentiels pour rapport au rythme sinusal, destines a des stimulateurs cardiaques - Google Patents

Procede et appareil preferentiels pour rapport au rythme sinusal, destines a des stimulateurs cardiaques Download PDF

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Publication number
WO1995009661A2
WO1995009661A2 PCT/US1994/010158 US9410158W WO9509661A2 WO 1995009661 A2 WO1995009661 A2 WO 1995009661A2 US 9410158 W US9410158 W US 9410158W WO 9509661 A2 WO9509661 A2 WO 9509661A2
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WO
WIPO (PCT)
Prior art keywords
escape intervals
intervals
rate
heart
sinus
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US1994/010158
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English (en)
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WO1995009661A3 (fr
Inventor
John C. Stroebel
H. Toby Markowitz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Medtronic Inc
Original Assignee
Medtronic Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Medtronic Inc filed Critical Medtronic Inc
Priority to AU78714/94A priority Critical patent/AU7871494A/en
Publication of WO1995009661A2 publication Critical patent/WO1995009661A2/fr
Publication of WO1995009661A3 publication Critical patent/WO1995009661A3/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/18—Applying electric currents by contact electrodes
    • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
    • A61N1/362—Heart stimulators
    • A61N1/365—Heart stimulators controlled by a physiological parameter, e.g. heart potential
    • A61N1/368—Heart stimulators controlled by a physiological parameter, e.g. heart potential comprising more than one electrode co-operating with different heart regions
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/18—Applying electric currents by contact electrodes
    • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
    • A61N1/362—Heart stimulators
    • A61N1/365—Heart stimulators controlled by a physiological parameter, e.g. heart potential
    • A61N1/36585—Heart stimulators controlled by a physiological parameter, e.g. heart potential controlled by two or more physical parameters

Definitions

  • the present invention relates to dual chamber, rate- responsive pacemakers. 2. Description of the Prior Art
  • Dual chamber pacing modes have been widely adopted for 0 pacing therapy.
  • the dual chamber operating modes is the "DDD" mode, which can pace an atrium and a ventricle, senses both the atrium and the ventricle, and can either inhibit or trigger pacing stimuli for both chambers.
  • This mode has a sensor augmented variant mode called “DDDR", 5 where the "R” stands for rate-adaptive or rate modulation.
  • a DDD pacemaker includes an atrial sense amplifier to detect atrial depolarizations of the heart, and a ventricular sense amplifier to detect ventricular depolarizations of the heart. If the atrium of the heart fails to beat within a predefined time interval (atrial escape interval) , the pacemaker supplies an atrial stimulus to the atrium through an appropriate lead system.
  • the pacemaker supplies a ventricular pacing stimulus to the ventricle through an appropriate lead system, if the ventricle fails to depolarize on its own.
  • Pacemakers which perform this function have the capability of tracking the patient's natural sinus rhythm and preserving the hemodynamic contribution of the atrial contraction over a wide range of heart rates.
  • SA sinoatrial
  • SSS Sick Sinus Syndrome
  • the DDDR mode provides some relief by pacing the atria and ventricles at a sensor rate determined by a sensor which senses a physiological indicator of the patients' metabolic needs.
  • sensor rates are sometimes too high and sometimes too low for a variety of reasons, including, errors related to the input of programmable parameters, limitations of the sensor's ability to accurately sense the physical quantity being sensed, and limitations or problems with the algorithm used to determine the sensor rate.
  • pacemakers operating in prior art sensor driven pacing modes pace at the sensor rate (and overdrive the atrium) whenever the sensor rate exceeds the sinus rate, even when the sinus rate is actually appropriate, and even when the difference between the two rates is too small to provide any discernible benefit in pacing at the higher sensor rate. Inappropriate. sensor rate pacing can lead to unnecessary overdrive of the atrium, and unwarranted expenditure of battery energy.
  • a rate-responsive pacemaker for pacing a patient's heart at a pacing rate, at least including: atrial pace stimulator means for generating an atrial pacing stimulus when needed; atrial sensing means for generating an atrial sensed event signal in response to a depolarization of atrial tissue; ventricular pace stimulator means coupled to the atrial pace stimulator means and the atrial sensing means for generating a ventricular pacing stimulus following an atrioventricular interval; and sensor rate means coupled to the atrial pace stimulator means for deriving a sensor rate related to physiologic demand on the heart; wherein the pacing rate tracks the patient's sinus rate unless the sensor rate exceeds the sinus rate by a predetermined margin, in which case the pacing rate is changed to the sensor rate.
  • a pacing method for pacing a patient's heart with a rate-responsive pacemaker at a pacing rate at least including the steps of: generating an atrial pacing stimulus when needed; generating an atrial sensed event signal in response to a depolarization of atrial tissue; generating a ventricular pacing stimulus following an atrioventricular interval; and deriving a sensor rate related to physiologic demand on the heart; wherein the pacing rate tracks the patient's sinus rate unless the sensor rate exceeds the sinus rate by a predetermined margin, in which case the pacing rate is changed to the sensor rate.
  • Figure 1 is block level diagram of a DDDR pacemaker capable of implementing the Sinus Preference Algorithm of the present invention.
  • Figure 2 is a timing diagram depicting Sinus
  • Preference Windows of the present invention in response to atrial paced and sensed events
  • Figure 3 is a continuation of the timing diagram in Figure 2.
  • Figure 4 is a graph of heart rate versus time using the Sinus Preference Algorithm of the present invention.
  • Figure 5 is a resulting electrocardiogram in response to changing Sinus Preference Windows and the occurrence of atrial sensed events.
  • Figure 6 is a graph of ventricular rate versus time, illustrating several recovery beats after the maximum rate drop has been reached.
  • FIG. 1 is block level diagram which sets forth the structures required to incorporate the invention into a DDD/DDDR pacemaker.
  • the patient's heart 10 has an atrial pacing lead 12 passed into the right atrium and a ventricular lead 9 passed into the right ventricle.
  • the atrial lead 12 has an atrial electrode array 13 which couples the pacemaker 14 to the atrium.
  • the ventricular lead 9 has a ventricular electrode array 15 for coupling the pacemaker 14 to the ventricular tissue of a patient's heart 10.
  • the atrial electrode array 13 is coupled to both an atrial pace stimulus generator 16 (APG) , and an atrial sense amplifier 17 (ASA) .
  • APG atrial pace stimulus generator 16
  • ASA atrial sense amplifier 17
  • the ventricular electrode array 15 is coupled to a ventricular pace stimulus generator 18 (VPG) and a ventricular sense amplifier 19 (VSA) .
  • VPG ventricular pace stimulus generator 18
  • VSA ventricular sense amplifier 19
  • FIG. 1 shows a preferred patient activity sensor (PAS) 21 and appropriate signal conditioning circuitry, which can be provided to alter the pacemaker operation in response to the sensed motion of the patient.
  • PAS patient activity sensor
  • An appropriate activity-based, rate-responsive system is taught by U.S. Patent 4,428,378 to Anderson et al., which is incorporated by reference herein. It should be appreciated that alternate sensors can be provided to achieve rate and postventricular atrial refractory period (PVARP) variation based upon other sensed physical parameters.
  • PVARP rate and postventricular atrial refractory period
  • the atrial sense amplifier ASA 17 detects depolarizations of atrial tissue and generates an atrial sensed event (ASE) to indicate the detection of an atrial beat of the patient's heart.
  • the ventricular sense amplifier VSA 19 responds to a ventricular beat of the patient's heart and generates a corresponding ventricular sensed event (VSE) .
  • VSE corresponding ventricular sensed event
  • the pacemaker logic 20 which is coupled to the sense amplifiers, generates various time intervals in response to detected atrial and ventricular sensed events, and generates both atrial paced event and ventricular paced event signals in response to timer logic and the sense amplifier signals.
  • the principal timing functions are set forth in Table 1, below.
  • timer logic 20 is provided with means to time out a programmed AV delay period (AVD) .
  • the AV delay period is initiated by the occurrence of either an atrial sensed or atrial paced event.
  • the AV delay period may end with the generation of a ventricular paced event (VPE) .
  • VPE ventricular paced event
  • Logic 20 also provides for a programmed post ventricular atrial refractory period (PPVARP) .
  • the PPVARP period begins with either a ventricular paced event (VPE) or a ventricular sensed event (VSE) , and expires at the conclusion of a physician-set time interval.
  • VPE ventricular paced event
  • VSE ventricular sensed event
  • the logic also times out a refractory limit interval (RLI) which begins with the occurrence of a ventricular sensed or paced event.
  • Pacemaker logic 20 also times out a disable interval period of a fixed but physician-selected duration. This disable interval time period begins upon the occurrence of a ventricular paced event (VPE) in a pacemaker cycle where the next post ventricular atrial refractory period is extended.
  • Pacemaker logic 20 times out an upper rate limit interval (URL) . This timer is initiated by the occurrence of a ventricular paced event (VPE) or ventricular sensed event (VSE) , and limits the upper rate at which ventricular stimuli are delivered to the heart. Preferably two separate lower rate interval timer functions are provided.
  • the first is set by the physician when the base pacing rate is selected.
  • This DDD V-A time interval starts from the occurrence of a ventricular sensed event (VSE) or ventricular paced event (VPE) , and provided neither an ASE nor a VSE occurs during the V-A time interval, an atrial paced event (APE) is generated after the expiration of the V-A time interval.
  • the duration of the second lower rate time interval is a function of the measured patient activity acquired by the activity sensor 21.
  • this DDDR V-A time interval begins with a sensed or paced ventricular event (VSE or VPE, respectively) and has a time duration reflecting patient activity.
  • VSE sensed or paced ventricular event
  • VPE ventricular paced event
  • the pacemaker logic 20 is also coupled to paced event pulse generators.
  • atrial paced event signals are coupled to the atrial pace stimulus generator 16 to produce an atrial pacing stimulus while the ventricular paced event signal generates a ventricular pacing stimulus through the ventricular pace stimulus pulse generator 18.
  • a pacemaker employing the Sinus Preference Algorithm of the present invention tracks the sinus rate when the sinus rate exceeds the sensor rate.
  • the Sinus Preference Algorithm does not always cause the pacemaker to pace whenever the sensor rate exceeds the sinus rate.
  • the pacemaker 14 paces at the sensor rate, or a variation thereof, whenever the sensor rate exceeds the sinus rate by more than a programmable maximum rate drop. Otherwise, the pacemaker 14 tracks the sinus rate.
  • the Sinus Preference Algorithm will be explained in greater detail infra. , with reference to Figures 2-6. Details of the Sinus Preference Algorithm Operation
  • FIGS. 2 and 3 together, represent a timing diagram of an example of successive heart cycles which illustrate the operation of the present invention.
  • VPE ventricular paced event
  • APE atrial paced event
  • PAV paced atrioventricular
  • the pacemaker 14 paces at the sensor rate.
  • V-A sensor- derived ventricle-to-atrium
  • V-A sensor- derived ventricle-to-atrium
  • the pacemaker 14 delivers a pacing stimulus to the atrium.
  • the pacemaker 14 delivers a pacing stimulus signal to the ventricle.
  • an atrial sensed event occurs after a measured V-A interval (less than the sensor-derived V-A interval in this instance) , followed by a sensed atrioventricular (SAV) interval and a VPE.
  • the occurrence of the first ASE causes the algorithm to redefine the next atrial escape interval.
  • the previous measured V-A interval is compared to the sensor-derived V-A interval. If the sensor-derived V-A interval is the lesser of the two, the new atrial escape interval is set equal to the sensor-derived V-A interval plus the current SPW (in this instance, MaxSPW) .
  • the algorithm compares the sum of the previous measured V-A interval plus the previous SPW with the sensor-derived V-A interval. The greater of the two is chosen as the new atrial escape interval.
  • the first Sinus Preference Window SPW j ⁇ is set to correspond to the programmed maximum rate drop (MaxSPW) from the sensor rate allowable.
  • the Sinus Preference Algorithm endeavors to first pace at the sensor rate minus the maximum rate drop, to look for possible ASEs, thus searching for sinus node beats occurring within acceptable proximity to the sensor rate. If found, the pacemaker 14 then endeavors to track the sinus rate. Absent the above, the pacing rate remains at the maximum rate drop level for several recovery beats, as shown in Figure 6. At each succeeding heart cycle, the pacing rate is increased by a programmable "SPW Rate Change". From the SPW Rate Change, a corresponding delta is derived, where delta equals the inverse of SPW Rate Change, or the change in interval needed to accomplish the desired rate change. The delta is subtracted from each succeeding SPW.
  • the pacing rate is incremented each heart cycle by the SPW Rate Change until the sensor rate is reached, where the pacemaker 14 continues to pace until either an ASE occurs, or a programmable Sinus Check Interval (SCI) spanning several heart cycles expires.
  • SCI Sinus Check Interval
  • a second ASE occurs prior to the expiration of the new atrial escape interval; thus, the next Sinus Preference Window SPW 2 remains at MaxSPW, and the new atrial escape interval is chosen as described supra .
  • an APE occurs at its expiration followed in time by a VPE (see Figure 3) .
  • the algorithm paces at the level resulting from the maximum rate drop for several recovery beats (not shown in Figure 3) .
  • the pacing rate begins to increment by the SPW Rate Change, so that the SPW is decremented by delta.
  • SPW 3 equals SPW 2 minus delta
  • SPW equals SPW 3 minus delta .
  • an ASE occurs, which resets SPW 5 to MaxSPW.
  • Sinus Preference Algorithm The effect of the Sinus Preference Algorithm is illustrated by the example in Figure 4, which shows graphs of heart rate versus time for p-wave or sinus rate (dotted curve) , sensor rate (dashed curve) , and A-V pacing rate (solid curve) .
  • the sensor rate In the range of heart rates where sinus tracking is appropriate (“Sinus Appropriate”) , the sensor rate does not exceed the sinus rate by more than the SPW Maximum Rate Drop. In the range of heart rates where sensor tracking is appropriate (“Sinus Not Appropriate”) , the sensor rate exceeds the sinus rate by more than the SPW Maximum Rate Drop.
  • the pacemaker 14 begins incrementing the pacing rate until it reaches the sensor rate, where it remains until either the expiration of the SCI or the occurrence of an ASE.
  • the SCI is reset to zero, and begins counting each time the SPW is reset to MaxSPW.
  • the SCI expires when its programmed maximum count is reached.
  • the occurrence of an ASE might be interpreted as the return of the sinus rate to an appropriate one for the current physiologic demand on the heart, to which the pacemaker 14 can then begin tracking again.
  • Figure 5 shows an example of an electrocardiogram (ECG) and corresponding SPWs resulting from the occurrence of two ASEs.
  • ECG electrocardiogram
  • the present invention is not limited to any particular pacing mode, and can function with prior art modes such as DDDR, AAIR, WIR and DDIR.

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  • Health & Medical Sciences (AREA)
  • Cardiology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biophysics (AREA)
  • Physiology (AREA)
  • Engineering & Computer Science (AREA)
  • Biomedical Technology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Radiology & Medical Imaging (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Electrotherapy Devices (AREA)

Abstract

Un nouveau stimulateur cardiaque sensible au rythme et à mode double cavité, permettant de stimuler le c÷ur d'un patient, permet de suivre le rythme sinusal lorsque ce dernier est légèrement inférieur au rythme d'un capteur; en d'autres termes, en deçà d'une 'baisse de rythme maximale de fenêtre préférentielle sinusale' prédéterminée. Une stimulation au rythme du capteur s'effectue lorsque ce rythme dépasse le rythme sinusal par une valeur supérieure à ladite baisse de rythme maximale de fenêtre préférentielle sinusale. Selon le mode préféré de réalisation, une fenêtre préférentiel sinusale, qui se situe au bout de l'intervalle ventricule-oreillette, est progressivement réduite au gré de pulsations cardiaques successives par une valeur delta programmable afin d'augmenter le rythme de stimulation jusqu'à ce que ladite fenêtre atteigne une valeur nulle, dans lequel cas le stimulateur effectue une stimulation au rythme du capteur. La fenêtre préférentielle sinusale est remise à sa valeur maximale soit lorsqu'un incident auriculaire est détecté, soit à la fin d'un intervalle de vérification sinusale programmable. Le stimulateur fonctionne au rythme sinusal ou au rythme de baisse de rythme maximale, en fonction du plus rapide des deux, pendant un nombre de pulsations de rétablissement, puis augmente progressivement le rythme de stimulation jusqu'au rythme du capteur.
PCT/US1994/010158 1993-09-29 1994-09-14 Procede et appareil preferentiels pour rapport au rythme sinusal, destines a des stimulateurs cardiaques Ceased WO1995009661A2 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU78714/94A AU7871494A (en) 1993-09-29 1994-09-14 Sinus preference method and apparatus for cardiac pacemakers

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US12963193A 1993-09-29 1993-09-29
US08/129,631 1993-09-29

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Publication Number Publication Date
WO1995009661A2 true WO1995009661A2 (fr) 1995-04-13
WO1995009661A3 WO1995009661A3 (fr) 1995-05-26

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996015828A1 (fr) * 1994-11-22 1996-05-30 Medtronic, Inc. Methode dite de la preference sinusale et appareillage pour stimulateurs cardiaques
EP0880979A1 (fr) 1997-05-16 1998-12-02 ELA MEDICAL (Société anonyme) Stimulateur cardiaque, défibrillateur et/ou cardioverteur à réduction des épisodes d'arythmie auriculaire
WO2004047919A3 (fr) * 2002-11-22 2004-07-22 Medtronic Inc Cardioverteur/defibrillateur implantable sous-cutane
CN114306937A (zh) * 2022-01-10 2022-04-12 丹源医学科技(杭州)有限公司 心房动态超速起搏装置

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5085215A (en) * 1990-03-20 1992-02-04 Telectronics Pacing Systems, Inc. Metabolic demand driven rate-responsive pacemaker
US5144949A (en) * 1991-03-15 1992-09-08 Medtronic, Inc. Dual chamber rate responsive pacemaker with automatic mode switching
US5342405A (en) * 1991-08-05 1994-08-30 Siemens Pacesetter, Inc. System and method for selecting a mode of operation of a dual-chamber pacemaker
US5350409A (en) * 1993-04-19 1994-09-27 Vitatron Medical, B.V. Rate adaptive pacemaker with adjustment of sensor rate as a function of sensed sinus rate

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996015828A1 (fr) * 1994-11-22 1996-05-30 Medtronic, Inc. Methode dite de la preference sinusale et appareillage pour stimulateurs cardiaques
EP0880979A1 (fr) 1997-05-16 1998-12-02 ELA MEDICAL (Société anonyme) Stimulateur cardiaque, défibrillateur et/ou cardioverteur à réduction des épisodes d'arythmie auriculaire
WO2004047919A3 (fr) * 2002-11-22 2004-07-22 Medtronic Inc Cardioverteur/defibrillateur implantable sous-cutane
US7069075B2 (en) 2002-11-22 2006-06-27 Medtronic, Inc. Subcutaneous implantable cardioverter/defibrillator
US7383085B2 (en) 2002-11-22 2008-06-03 Medtronic, Inc. Subcutaneous implantable cardioverter/defibrillator
CN114306937A (zh) * 2022-01-10 2022-04-12 丹源医学科技(杭州)有限公司 心房动态超速起搏装置
CN114306937B (zh) * 2022-01-10 2022-06-28 丹源医学科技(杭州)有限公司 心房动态超速起搏装置

Also Published As

Publication number Publication date
AU7871494A (en) 1995-05-01
WO1995009661A3 (fr) 1995-05-26

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