If its going to happen, it will happen to me!

I have a long history of medical problems eg. ovarian cysts, hysterectomy, bowel rupture resulting in 2 failed colostomy's and a functioning ileostomy up till 2000. While walking my dog in the park about 3 years ago I had a sudden episode of really rapid heart rate. I went to the doctor the next day and was fobbed off with it being a panic attack. This I knew was not what had happened so made another appointment with my regular GP and she referred me to the local hospital cardiac clinic. After many many months of back and forth tests, 24 hour recordings, a week long recording, ECGs, Echos, etc,etc. I was finally told it was Atrial Fib. For months I took pills to control it but they either made me sick, affected the meds I already take or just didn't work. Finally I had a Dual chamber pacemaker put in last April. I hoped I would be fixed but the AF was as bad as ever and I was finding I could do less and less. In October I had AV node ablation and it was hoped that would be it but since then I have been so breathless I can hardly ever walk the dog myself nor can I get up the stairs or walk too far. I have told them and told them things are getting worse until yesterday my cardiologist said the reason I am being affected this way is because I am one of a small minority of patients who have an adverse affect from the artificial pacing beat. As a result I am now going to have my pacemaker replaced with a Bi Chamber model. I hope this makes a difference.. Anyone else have a similar story. I have looked for case studies like mine but as has been my history with medicine if something is going to go wrong it will happen to me!!

2 Comments

Asuse I am having eptopicnwer

by Bea - 2008-04-02 07:04:42

Bi chamber means 3 leads.. Usually used for congestive heart failure from what little I have read. Because I am having eptopic beats as well as the breathlessness this is what I have been told is the next step.

Bi-Chamber Pacemaker.

by Stepford_Wife - 2008-04-02 08:04:19

From what I have read, it sounds like something I could benefit from.
My story is very similar to yours, medications, ablations, finally AV node ablation and a dual chamber pacer, but that hasn't solved my episodes of Afib.
If you get this bi-chamber pacer, let me know how it's working for you, I'm very interested.
Meanwhile, here is what I found on the subject.
Take care,

~ Dominique ~

Dual-chamber pacemaker system for simultaneous bi-chamber pacing and sensing
US Patent Issued on September 27, 2005

Inventor(s)

Malcolm J. Begemann
Geeske Van Oort


Assignee

Medtronic, Inc.


Application

No. 024226 filed on 2001-12-21
Current US Class

607/9 , Heart rate regulating, (e.g., pacing) 607/28 Measuring pacing threshold, capture margin, or contact impedance
Field of Search

607/14 , Treating or preventing abnormally high heart rate 607/15 , Selecting plural stimulation patterns 607/28 , Measuring pacing threshold, capture margin, or contact impedance 607/36 , Feature of stimulator housing or encapsulation 607/4 , Combined cardioverting/defibrillating and pacing 607/9 Heart rate regulating, (e.g., pacing)
Examiners

Primary: Jeffrey R Jastrzab
Assistant: Roderick Bradford


Attorney, Agent or Firm

Wolde-Michael; Girma, Chapilc; Daniel G.


US Patent References

5720768
Dual chamber pacing with interchamber delay
Issued on: February 24, 1998
Inventor: Verboven-Nelissen


Foreign Patent References
0990451 EP. Apr., 2000
WO 00/04950 WO 20000200
WO 01/36040 WO 20010500




Abstract Claims Description Full Text

Description


FIELD OF THE INVENTION

The present invention relates to the field of implantable medical devices, and, more particularly, to dual-chamber cardiac pacing systems that are capable of switching electrode configurations when two unipolar leads are disposed in opposing heart chambers (i.e., left and right atria or left and right ventricles).

BACKGROUND OF THE INVENTION

Tachyarrhythmias are episodes of high-rate cardiac depolarizations. Tachyarrhythmias may occur in one chamber of the heart or may be propagated from one chamber to another. Some tachyarrhythmias are sufficiently high in rate to compromise cardiac output from the chamber(s) affected, leading to loss consciousness or death, in the case of ventricular fibrillation or weakness and dizziness in the case of atrial fibrillation. Atrial fibrillation is often debilitating, due to the loss of atrial cardiac output, and may sometimes lead to ventricular fibrillation.

Generally, fibrillation may be terminated by administering high energy level cardioversion/defibrillation shocks or pulses until the fibrillation is terminated. For example, in the context of implantable anti-arrhythmia devices, these pulses may be applied by means of large surface area electrodes on or in the chamber to be defibrillated. However, the high energy level pulses are often sufficient to cause pain to the patient. Thus, it would be desirable to prevent or decrease the occurrence of atrial fibrillation without the delivery of high energy level pulses.

Some exploration has, therefore, been made in the use of pacing level pulses, which stimulate the cardiac tissue at much lower levels than defibrillation pulses, to terminate atrial fibrillation.

Implantable pulse generators (IPGs) that deliver pacing level pulses are well known in the art. These IPGs may deliver pulses to one or more chambers of the heart. Some of these devices provide pacing stimuli to the heart at a predetermined rate. The stimuli may be applied at a fixed rate, on demand, at a rate synchronized to atrial activity or at a rate synchronized to ventricular activity. This type of pacing function may also be used in other devices such as, for example, implantable cardioverter defibrillators (ICDs) or in external pacemakers. Most IPGs include sense amplifier circuitry for detecting intrinsic cardiac electrical activity. Some IPGs also include sensors or sensing electrodes to determine reliably the heart rate (or pacing rate) in a heart under different conditions. Some IPGs are dual-chamber, having both atrial and ventricular leads. These IPGs have a unipolar lead in the ventricle and a unipolar lead in the atrium.

To deliver pacing pulses of sufficient magnitude to have the desired effect, it may be desirable to stimulate or sense more than one chamber of the heart simultaneously. This may be desirable, for example, because the simultaneous stimulation in opposing chambers results in stimulation pulses of higher amplitude or duration. This may also be desirable because stimulation across opposing chambers of the heart stimulates a desired location of tissue that is more difficult to stimulate across only one chamber of the heart. In standard IPGs, a minimum atrio-ventricular delay makes such simultaneous stimulation difficult or impossible. That is, there is a minimum delay between the time a first chamber, for example the left atria, is stimulated/sensed and the time the second chamber, for example the right atria, is stimulated/sensed.

It would also be desirable to provide stimulation to opposing chambers of the heart using standard programming settings and existing fixed connections in an IPG without the addition of further splitters and adapters.

It would also be desirable to provide switchable configurations of electrodes disposed in opposing atria or ventricles of the heart.

Thus, a need exists in the medical arts for simultaneous stimulation and/or sensing of opposing chambers of a heart.

Several methods have been proposed in the prior art for improving an implantable device's ability to administer pacing pulses simultaneously to more than one chamber of a heart.

For example, U.S. Pat. No. 5,514,161 to Limousin, entitled "Methods and Apparatus for Controlling Atrial Stimulation in a Double Atrial Triple Chamber Cardiac Pacemaker", hereby incorporated by reference in its entirety, discloses a double atrial triple chamber pacemaker, which provides simultaneous stimulation to both atria through the provision of a Y connector.

U.S. Pat. No. 5,757,970 to Pouvreau, entitled "System, Adaptor and Method to Provide Medical Electrical Stimulation" discloses an adaptor that permits a single channel of stimulation to be split and provided to two areas of the heart by adjusting the amplitude of the stimulation pulses.

The article "Permanent Multisite Cardiac Pacing" by Barold, et al. in the journal PACE discloses the use of a Y connector to split a standard bipolar output into anode and cathode electrodes.

The article "Hemodynamic Benefits of Permanent Atrial Resynchronization Patients with Advanced Inter Atrial Blocks, paced DDD Mode" by Daubert et al. in the journal PACE discloses the use of a bifurcated electrode to pace between the right atrium and the coronary sinus in order to pace both atria simultaneously.

As discussed above, the most pertinent prior art patents are shown in the following table:

All the publications listed in Table 1 are hereby incorporated by reference herein in their respective entireties. As those of ordinary skill in the art will appreciate readily upon reading the Summary of the Invention, the Detailed Description of the Preferred Embodiments and the claims set forth below, many of the devices and methods disclosed in the patents of Table 1 may be modified advantageously by using the teachings of the present invention.

SUMMARY OF THE INVENTION

The present invention is therefore directed to providing a method and system for simultaneously stimulating and/or sensing opposing chambers of the heart. The system of the present invention overcomes at least some of the problems, disadvantages and limitations of the prior art described above, and provides a more efficient and accurate means of stimulating opposing chambers of a heart.

The present invention has certain objects. That is, various embodiments of the present invention provide solutions to one or more problems existing in the prior art respecting the pacing of cardiac tissue. Those problems include, without limitation: (a) difficulty in simultaneous stimulation of opposing chambers of the heart; (b) need to add splitters, adapters and additional circuitry to an existing IPG in order to accomplish simultaneous stimulation; (c) difficulty in determining appropriate sensing configurations using one or more leads; (d) difficulty in optimizing contractions induced in an opposing chamber of the heart; (e) difficulty in varying cathode and anode functions of electrodes disposed in opposing chambers, (f) difficulty in testing and determining which chamber of the heart provides the lowest pacing threshold; (g) difficulty in configuring electrodes already disposed in opposing chambers of the heart to take advantage of the lowest pacing threshold; (h) need to change circuitry or software/firmware in order to switch electrode configurations.

In comparison to known pacing techniques, various embodiments of the present invention provide one or more of the following advantages: (a) ability to provide simultaneous stimulation to opposing chambers of a heart; (b) ability to provide bi-atrial or bi-ventricular stimulation without an atrio-ventricular delay; (c) ability to reversibly select an anode electrode and a cathode electrode for simultaneous stimulation without removing either electrode from its existing connection; (d) ability to switch and/or select electrode configurations of electrodes already disposed in opposing chambers of the heart; (e) ability to switch and/or select polarity of a given electrode already disposed in a chamber of the heart; (f) ability to optimize hemodynamics of induced contractions in an opposing chamber of the heart; (g) ability to test and determine the chamber having the lowest pacing threshold and configure the electrodes to take advantage of the lowest pacing threshold without using specialized lead adapters; and (h) ability to test and determine the chamber having the lowest pacing threshold and configure the electrodes to take advantage of the lowest pacing threshold without removing the leads from the connector block and re-inserting them in different connector receptacles.

Some embodiments of the present invention include one or more of the following features: (a) an IPG capable of providing bi-atrial or bi-ventricular stimulation without an atrio-ventricular delay; (b) an IPG capable of reversibly switching anode and cathode electrodes for simultaneous stimulation without additional adapters or connectors; (c) an IPG capable of testing opposing chambers to determine which chamber has the lowest pacing threshold and of configuring the electrodes to take advantage of the lowest pacing threshold; (d) an IPG in which the polarity of various electrodes is selectable and/or switchable; (e) an IPG capable of providing staggered stimulation to optimize hemodynamics of induced contractions (f) methods of reversibly selecting an anode electrode and a cathode electrode for simultaneous stimulation without removing either electrode from its existing connection; (g) methods of switching and/or selecting electrode configurations of electrodes already disposed in opposing chambers of the heart; (h) methods of switching and/or selecting polarity of a given electrode disposed in a chamber of the heart; and (i) methods of optimizing hemodynamics of induced contractions in an opposing chamber of the heart.

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Hi, I am 47 and have had a pacemaker for 7 months and I’m doing great with it.