Surgery: light – thermal – and electrical application – Light – thermal – and electrical application – Electrical therapeutic systems
Reexamination Certificate
2001-03-14
2004-07-06
Jastrzab, Jeffrey R. (Department: 3762)
Surgery: light, thermal, and electrical application
Light, thermal, and electrical application
Electrical therapeutic systems
C600S518000
Reexamination Certificate
active
06760620
ABSTRACT:
BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention generally relates to devices, systems, and methods for diagnosing and/or treating of the heart. In a particular embodiment, the invention provides techniques for localizing and/or treating atrial fibrillation and other arrhythmias.
Significant progress has recently been made toward effective treatments of many cardiac arrhythmias. Contraction of a healthy human heart generally propagates through the heart tissue from the sinus node in the right atrium, and eventually the associated ventricles. This normal propagation of contraction forces blood to flow from the atria to the ventricles in a synchronized pumping action. Focal or re-entrant arrhythmias of the heart often originate at, and propagate from alternative heart tissue locations, resulting in irregular contractions of some or all of the heart tissues. Radiofrequency intracardiac catheter ablation of the alternative ectopic origin is now used to effectively treat a variety of arrhythmias, including ventricular tachyeardia (VT).
Although quite effective, current catheter ablation of arrhythmogenic sites has significant disadvantages. A particular challenge in an effective catheter ablation treatment is the time required for proper identification of the treatment site. As it is generally desirable to limit the size of the ablation, significant time is often spent testing candidate ablation sites. These candidate sites are often tested sequentially by positioning the intracardiac catheter against a site within (for example) the right ventricle, identifying the engaged tissue location within the ventricle, sensing and/or pacing the heart at the candidate site, repositioning the intracardiac catheter to a new candidate site, and repeating this process until the ectopic origin has been identified.
As fluoroscopy is often used to identify the location of the engaged tissue, this sequential iterative process can result in significant exposure of the patient and treating personnel to potentially harmful radiation. While alternative (and more complex) intracardiac catheter probe structures have been proposed to allow more rapid identification of the ectopic origin(s) of VTs and other focal arrhythmias, the size and cost of these complex structures may limit their acceptability, particularly for treatment of (for example) the left atrium of the heart, which is often accessed from the right atrium by a puncture through the atrial septum.
To overcome the disadvantages associated with these known time consuming and/or invasive intracardiac arrhythmia sensing and localization techniques, researchers have been working on alternative arrhythmia localization techniques which rely on body surfacing mapping often during pacing. Pacing often comprises initiating the arrhythmia by applying a small electrical pulse from a catheter. Electrocardiograms (ECG) may be recorded during abnormal atrial or ventricular activity and compared with ECGs taken during pacing at different sites within the heart, optionally using a standard 12-lead ECG system. More detailed information regarding ectopic sites can be obtained by recording heart cycle signals at the body surface using a more comprehensive sensor array. These heart cycle signals, which generally comprise small amplitude variations in electrical potential along the anterior and/or posterior torso, can be manipulated and/or mapped so as to provide an indication of the origin of the arrhythmia within the heart. Much of this work has concentrated on VT. More recent work has begun to investigate the possibility of localizing certain atrial arrhythmias, such as right atrial tachycardia. While the initial results of this research appear quite promising for treatment of selected individuals, significant advancements would be beneficial to allow widespread treatment of patients suffering from cardiac arrhythmias.
The most common form of cardiac arrhythmia may be atrial fibrillation (AFib). Atrial fibrillation is often paroxysmal in nature, which may contribute to the significant risks of the disorder. Atrial fibrillation may result in twice as many hospitalizations annually as VT, and may cause significant morbidity and/or mortality, leading not only to heart failure, but associated risks of thrombo-embolism and stroke.
Many current AFib patients are managed using antiarrhythmic drugs. Unfortunately, existing drug treatments are merely palliative, since they are aimed at suppression of the arrhythmia and not at curing the underlying disease. Many researchers are directing resources to development of therapeutic catheters to treat atrial fibrillation, attempting to build on several years of successful ablation for treatment of other arrhythmias. Early indications are that when accurately identified, ablation of ectopic origins of focal AFib may provide an effective treatment for the disorder. Hence, there would be significant benefits to extending the new body surface localization techniques to atrial fibrillation. The nature of AFib, however, represents a significant barrier to the direct application of known mapping techniques used with other arrhythmias.
Atrial fibrillation is generally more complex and difficult to localize than other arrhythmias. Focal AFib often exhibits an infrequent, irregular occurrence, and may be difficult to induce with known catheter mapping techniques. Even when atrial fibrillation is ongoing and/or successfully induced in the lab, AFib may exhibit prolonged occurrences in many patients, possibly requiring repetitive direct current shock cardioversion to convert the patient back into a normal sinus rhythm. Atrial fibrillation may also have multiple focal arrhythmia sources, possibly leading to detailed catheter mapping and unacceptably long procedures. Procedure times in general may be excessively long, particularly when conducted under prolonged fluoroscopic imaging, leading to excessive x-ray exposure to the patient, physician, and nursing staff. The current invasive options for AFib mapping also have significant disadvantages, particularly when they involve extended and/or traumatic catheter manipulation in the left atrium.
In light of the above, it would be desirable to provide improved devices, systems, and methods for localizing and/or treating AFib and other arrhythmias within a heart of a patient. The present invention provides such improvements, mitigating and/or overcoming at least some of the disadvantages of known approaches for diagnosing and treating arrhythmias.
II. Related Art
The following patents may be relevant to the subject matter of the present invention, and their full disclosures incorporated herein by reference: U.S. Pat. No. 5,311,873; and U.S. Pat. No. 5,634,469. Peeters, H. A. P., SippensGroenewegen, A. and others described “Clinical Application of an Integrated 3-Phase Mapping Technique for Localization of the Site of Origin of Idiopathic Ventricular Tachycardia” in
Circulation,
99:1300-1311 (1999). SippensGroenewegen, A. et al. also described “Body Surface Mapping of a trial Arrhythmias: Atlas of Paced P wave Integral Maps to Localize the Focal Origin of Right Atrial Tachycardia”, in
J. Electrocardiol.,
31(Supp.):85-91 (1998). Related work was described by SippensGroenewegen, A. et al. in, “Value of Body Surface Mapping in Localizing the Site of Origin of Ventricular Tachycardia in Patients with Previous Myocardial Infarction”,
J. Am. Coll. Cardiol.
24:1708-1724 (1994). Each of these references is incorporated herein by reference.
SUMMARY OF THE INVENTION
The present invention provides improved devices, systems, and methods for localizing and/or treating arrhythmias of a heart. The techniques of the present invention are particularly useful for localizing atrial fibrillation, and allow locating arrhythmogenic regions of a chamber of the heart using heart cycle signals measured from a body surface of the patient. Non-invasive localization of the ectopic origin allows focal treatment to be quickly targeted to effectively inhibit these complex arrhythmias without havin
Barrish, Esq. Mark D.
Jastrzab Jeffrey R.
Resolution Medical, Inc.
Townsend&Townsend&Crew LLP
LandOfFree
Non-invasive localization and treatment of focal atrial... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Non-invasive localization and treatment of focal atrial..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-invasive localization and treatment of focal atrial... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3216973