Surgery: light – thermal – and electrical application – Light – thermal – and electrical application – Electrical therapeutic systems
Reexamination Certificate
1998-12-04
2001-03-20
Layno, Carl H. (Department: 3762)
Surgery: light, thermal, and electrical application
Light, thermal, and electrical application
Electrical therapeutic systems
C607S015000
Reexamination Certificate
active
06205357
ABSTRACT:
FIELD OF THE INVENTION
The present invention concerns methods and apparatus for preventing atrial and/or ventricular arrhythmia prior to occurrence thereof, and treating such arrhythmia if it should occur.
BACKGROUND OF THE INVENTION
Atrial fibrillation is one of the most common cardiac arrhythmia. Health consequences associated with atrial fibrillation include decreased cardiac output, less regular ventricular rhythm, the formation of blood clots in the atrial appendages, and an increased incidence of stroke. While some drugs are available for the treatment of atrial fibrillation, they have a number of side effects which reduce their therapeutic utility.
Unlike patients afflicted with ventricular fibrillation, patients afflicted with atrial fibrillation are conscious. The pain associated with the administration of the defibrillation shock can be severe, and there is a need for means of carrying out atrial defibrillation in a manner that is less painful to the patient being treated.
Numerous patients are afflicted with both atrial and ventricular arrrhythmias. For such patients, it would be desirable to provide a single device that can carry out both atrial and ventricular defibrillation with minimum shock strength, and with minimal surgical intervention.
U.S. Pat. No. 5,549,641 to Ayers et al., issued Aug. 27, 1996, describes an atrial cardioverter and method in which atrial arrhythmia is first detected. If no arrhythmia is detected, then no action is taken. If arrhythmia is detected, the system proceeds through determining whether the arrhythmia is an atrial flutter, or a more severe arrhythmia, and a therapeutic pulse ranging from pace pulses or low energy cardioversion through intermediate and high energy cardioversion is given. A disadvantage of this system is that it is not capable of preventing an arrhythmia prior to occurrence thereof. Other systems which provide different levels of therapeutic pulses, but only after the onset of an arrhythmia, are described in U.S. Pat. No. 4,375,817 to Engle et al., U.S. Pat. No. 4,869,252 to Gilli, and U.S. Pat. No. 5,350,401 to Levine.
A problem with the aforesaid devices is that therapy begins only after the onset of arrhythmia. It would be preferable to have a device that incorporated prognostic features and preventive therapy to prevent arrhythmia from initiating, and, if arrhythmia should initiate, to promptly treat the arrhythmia.
SUMMARY OF THE INVENTION
A first aspect of the invention is a method of selecting a cardiac therapy to be delivered to a patient's heart for the prevention or treatment of cardiac arrhythmia by an implantable system. The method comprises detecting electrical activity from the heart of the patient, predicting the future onset of a cardiac arrhythmia in the patient from the detected electrical activity (i.e., before the arrhythmia actually occurs), and then delivering a first therapeutic electrical pulse to the heart of the patient prior to the onset of cardiac arrhythmia. The arrhythmia monitored for may be an atrial arrhythmia, a ventricular arrhythmia, or both. After the first therapeutic electrical pulse is delivered, the effectiveness of that pulse in preventing cardiac arrhythmia is then monitored from the detected electrical activity. A second therapeutic electrical pulse is then delivered to the heart of the patient at the onset of the cardiac arrhythmia if the first therapeutic electrical pulse is not effective. In a preferred embodiment, the step of delivering a second therapeutic electrical pulse is followed by the steps of: monitoring the effectiveness of the second therapeutic electrical pulse in treating the cardiac arrhythmia, and then delivering a third therapeutic electrical pulse to the heart of the patient if the second therapeutic electrical pulse is not effective in treating the arrhythmia. The third therapeutic electrical pulse is a higher energy pulse than the second therapeutic electrical pulse.
Systems for carrying out such methods are described in detail below. In a preferred embodiment, the system of the invention comprises a first sensing electrode configured for positioning through the coronary sinus ostium and within a vein on the left surface of the left ventricle of the heart for sensing electrical activity from the heart, and a detector operatively associated with the first sensing electrode for determining (e.g., diagnosing or prognosing) an arrhythmia with the sensed electrical activity. Typically the system further comprises a second sensing electrode configured for positioning in the right ventricle of the heart, where the detector is operatively associated with both the first sensing electrode and the second sensing electrode. The second sensing electrode may be positioned in other locations as well, such as also within a vein on the left surface of the left ventricle of the heart (although spaced apart from the first sensing electrode), in the right atrium, in the superior vena cava, etc. Finally, a third sensing electrode may also be included, with the third electrode positioned in any of the foregoing locations (again, spaced apart from the first and second electrodes), with the detector operatively associated with all of the first, second, and third sensing electrodes. Determination of a medical condition may be carried out by any suitable means, such as by detecting premature beats in the heart. This method is particularly useful for identifying the chamber of premature beat origin (e.g., left ventricle, right ventricle, left atrium, or right atrium).
The detector may be configured to detect the presence of sinus rhythm with syntactic relationships among electrogram features. The detector may be configured to predict cardiac arrhythmia in the patient prior to the onset of the cardiac arrhythmia, or the present occurrence of cardiac arrhythmia in the patient. The detector may be configured to discriminate the location of origin of premature beats in the heart (e.g., to discriminate an atrial location of origin from a ventricular location of origin of premature beats in the heart, with or without the ability to discriminate left ventricular from right ventricular locations of origin, and with or without the ability to discriminate left atrial from right atrial locations of origin).
In a particular embodiment, a method of selecting a cardiac therapy to be delivered to a patient's heart by an implantable system of the invention comprises detecting a first set of electrical activity from the heart from a first sensing electrode positioned within a vein on the surface of the left ventricle of the heart; detecting a second set of electrical activity from the heart from a second sensing electrode positioned within the right ventricle of the heart; then selecting an electrical therapy to be delivered by the implantable system based on the first and second sets of detected electrical activity; and then delivering the selected electrical therapy.
The first, second, and third therapeutic electrical pulses can be administered by any suitable means. In one embodiment, the system includes a first catheter configured for positioning in the right ventricle of the heart; a second catheter configured for positioning through the coronary sinus ostium and in the coronary sinus of the heart, with the first and second catheters together carrying at least three defibrillation electrodes. A power supply is included, a control circuit is operatively associated with the power supply and the electrodes. The control circuit is configured to deliver atrial therapeutic pulses through at least two of the electrodes, and/or ventricular therapeutic pulses through at least two of the electrodes.
The system may include a first and second pair of atrial therapeutic electrodes operatively associated with the control circuit and power supply, with the first pair of atrial therapeutic electrodes configured for delivering an atrial therapeutic pulse segment along a first current pathway and the second pair of atrial therapeutic electrodes configured for delivering a second atrial therapeut
Ideker Raymond E.
KenKnight Bruce H.
Warren Jay A.
Layno Carl H.
Myers Bigel & Sibley & Sajovec
UAB Research Foundation
LandOfFree
Methods and apparatus for detecting and treating medical... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods and apparatus for detecting and treating medical..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods and apparatus for detecting and treating medical... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2542121