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Recent Atrial Flutter News and Articles

• New Bradycardia Study Findings Recently Were Published by Researchers at Vanderbilt University
• Patent Issued for Systems and Methods for Use by an Implantable Medical Device for Controlling Multi-Site CRT Pacing in the Presence of Atrial Tachycardia
• New Electrophysiology Findings from Tohoku University Graduate School of Medicine Published
• New Research on Cardiovascular Research from University of Adelaide Summarized
• Patent Issued for Method of Forming Electrode Placement and Connection Systems
• Research from Na Homolce Hospital Reveals New Findings on Cardiology Research
• Patent Issued for Method and Apparatus for Trending a Physiological Cardiac Parameter
• Research from Washington University School of Medicine in the Area of Geriatrics and Gerontology Described
• New Cardiovascular Drugs and Therapies Research from Attikon University Hospital Outlined

Patent Issued for Method for Treating and Repairing Mitral Valve Annulus

The patent's inventors are Witzel, Thomas (Laguna Niguel, CA); Hauck, Wallace N (Irvine, CA); Osth, John A. (Laguna Hills, CA); Tu, Hosheng (Newport Beach, CA).

This patent was filed on May 15, 2007 and was cleared and issued on December 11, 2012.

From the background information supplied by the inventors, news correspondents obtained the following quote: "Over 12 million people around the world suffer from Congestive Heart Failure (CHF). This is a family of related conditions defined by the failure of the heart to pump blood efficiently resulting in congestion (or backing up of the blood) in the lungs or peripheral circulation. CHF can ultimately lead to end-organ failure, which contributes to death of the patient. The heart muscle of the CHF patient may be altered with the chambers dilated and the heart walls thickened or thinned. CHF can result from several conditions, including infections of the heart muscle or valve, physical damage to the valve or by damaged muscle caused by infarction (heart attack).

"CHF is the fastest growing cardiovascular disease with over 1 million new cases occurring each year. Conservative estimates suggest that the prevalence of CHF will more than double by 2007. If untreated, CHF may result in severe lifestyle restrictions and ultimately death. One of the causes of CHF and a very common contributor to the harmful effects of CHF is a leaky mitral heart valve. The mitral valve is located in the center of the heart between the two left or major heart chambers and plays an important role in maintaining forward flow of blood. The medical term for this leaky condition is 'mitral regurgitation' and the condition affects well over one million people globally. Mitral regurgitation is also called `mitral incompetence` or `mitral insufficiency`.

"For general background information, the circulatory system consists of a heart and blood vessels. In its path through the heart, the blood encounters four valves. The valve on the right side that separates the right atrium from the right ventricle has three cusps and is called the tricuspid valve. It closes when the ventricle contracts during a phase known as systole and it opens when the ventricle relaxes, a phase known as diastole.

"The pulmonary valve separates the right ventricle from the pulmonary artery. It opens during systole, to allow the blood to be pumped toward the lungs, and it closes during diastole to keep the blood from leaking back into the heart from the pulmonary artery. The pulmonary valve has three cusps, each one resembling a crescent and it is also known as a semi-lunar valve.

"The two-cusped mitral valve, so named because of its resemblance to a bishop's mitre, is in the left ventricle and it separates the left atrium from the ventricle. It opens during diastole to allow the blood stored in the atrium to pour into the ventricle, and it closes during systole to prevent blood from leaking back into the atrium. The mitral valve and the tricuspid valve differ significantly in anatomy. The annulus of the mitral valve is somewhat D-shaped whereas the annulus of the tricuspid valve is more nearly circular.

"The fourth valve is the aortic valve. It separates the left ventricle from the aorta. It has three semi-lunar cusps and it closely resembles the pulmonary valve. The aortic valve opens during systole allowing a stream of blood to enter the aorta and it closes during diastole to prevent any of the blood from leaking back into the left ventricle.

"In a venous circulatory system, a venous valve functions to prevent the venous blood from leaking back into the upstream side so that the venous blood can return to the heart and the lungs for blood oxygenating purposes.

"Clinical experience has shown that repair of a valve, either a heart valve or a venous valve, produces better long-term results than does valve replacement. Valve replacement using a tissue valve suffers long-term calcification problems. On the other hand, anticoagulation medicine, such as cumadin, is required for the life of a patient when a mechanical valve is used in valve replacement. The current technology for valve repair or valve replacement requires an expensive open-heart surgery that needs a prolonged period of recovery. A less invasive or catheter-based valve repair technology becomes an unmet clinical challenge.

"The effects of valvular dysfunction vary. Mitral regurgitation may have more severe physiological consequences to the patient than does tricuspid valve regurgitation. In patients with valvular insufficiency, it is an increasingly common surgical practice to repair the natural valve, and to attempt to correct the defects. Many of the defects are associated with dilation of the valve annulus. This dilatation not only prevents competence of the valve but also results in distortion of the normal shape of the valve orifice or valve leaflets. Remodeling of the annulus is therefore central to most reconstructive procedures for the mitral valve.

"As a part of the valve repair it is either necessary to diminish or constrict the involved segment of the annulus so that the leaflets may coapt correctly on closing, or to stabilize the annulus to prevent post operative dilatation from occurring. The current open-heart approach is by implantation of a prosthetic ring, such as a Cosgrove Ring or a Carpentier Ring, in the supra annular position. The purpose of the ring is to restrict and/or support the annulus to correct and/or prevent valvular insufficiency. In tricuspid valve repair, constriction of the annulus usually takes place in the posterior leaflet segment and in a small portion of the adjacent anterior leaflet.

"Various prostheses have been described for use in conjunction with mitral or tricuspid valve repair. The ring developed by Dr. Alain Carpentier (U.S. Pat. No. 3,656,185) is rigid and flat. An open ring valve prosthesis as described in U.S. Pat. No. 4,164,046 comprises a uniquely shaped open ring valve prosthesis having a special velour exterior for effecting mitral and tricuspid annuloplasty. The fully flexible annuloplasty ring could only be shortened in the posterior segment by the placement of plicating sutures. John Wright et al. in U.S. Pat. No. 5,674,279 discloses a suturing ring suitable for use on heart valve prosthetic devices for securing such devices in the heart or other annular tissue. All of the above valve repair or replacement requires an open-heart operation which is costly and exposes a patient to higher risk and longer recovery than a catheter-based, less invasive procedure.

"Moderate heat is known to tighten and shrink the collagen tissue as illustrated in U.S. Pat. Nos. 5,456,662 and 5,546,954. It is also clinically verified that thermal energy is capable of denaturing the tissue and modulating the collagenous molecules in such a way that treated tissue becomes more resilient ('The Next Wave in Minimally Invasive Surgery' MD&DI pp. 36-44, August 1998). Therefore, it becomes imperative to treat the inner walls of an annular organ structure of a heart valve, a valve leaflet, chordae tendinae, papillary muscles, and the like by shrinking/tightening techniques. The same shrinking/tightening techniques are also applicable to stabilize injected biomaterial to repair the defect annular organ structure, wherein the injectable biomaterial is suitable for penetration and heat initiated shrinking/tightening.

"One method of reducing the size of tissues in situ has been used in the treatment of many diseases, or as an adjunct to surgical removal procedures. This method applies appropriate heat to the tissues, and causes them to shrink and tighten. It can be performed in a minimal invasive or percutaneous fashion, which is often less traumatic than surgical procedures and may be the only alternative method, wherein other procedures are unsafe or ineffective. Ablative treatment devices have an advantage because of the use of a therapeutic energy that is rapidly dissipated and reduced to a non-destructive level by conduction and convection, to other natural processes.

"Radio frequency (RF) therapeutic protocol has been proven to be highly effective when used by electrophysiologists for the treatment of tachycardia, atrial flutter and atrial fibrillation; by neurosurgeons for the treatment of Parkinson's disease; by otolaryngologist for clearing airway obstruction and by neurosurgeons and anesthetists for other RF procedures such as Gasserian ganglionectomy for trigeminal neuralgia and percutaneous cervical cordotomy for intractable pains. Radiofrequency treatment, which exposes a patient to minimal side effects and risks, is generally performed after first locating the tissue sites for treatment. Radiofrequency energy, when coupled with a temperature control mechanism, can be supplied precisely to the device to tissue contact site to obtain the desired temperature for treating a tissue or for effecting the desired shrinking of the host collagen or injected bioresorbable material adapted to immobilize the biomaterial in place. Tweden, et al, in U.S. Pat. No. 6,258,122, entire content which are incorporated herein by reference, discloses that a bioresorbable heart valve annuloplasty prosthesis are eventually resorbed by the patient, during which time regenerated tissue replaces the prosthesis

"Edwards et al in U.S. Pat. No. 6,258,087, entire contents of which are incorporated herein by reference, discloses an expandable electrode assembly comprising a support basket formed from an array of spines for forming lesions to treat dysfunction in sphincters. Electrodes carried by the spines are intended to penetrate the tissue region upon expansion of the basket. However, the assembly disclosed by Edwards et al. does not teach a tissue-contactor member comprising a narrow middle region between an enlarged distal region and an enlarged proximal region suitable for sandwiching and compressing the sphincter for tissue treatment.

"Tu in U.S. Pat. No. 6,267,781 teaches an ablation device for treating valvular annulus or valvular organ structure of a patient, comprising a flexible elongate tubular shaft having a deployable spiral wire electrode at its distal end adapted to contact/penetrate the tissue to be treated and to apply high frequency energy to the tissue for therapeutic purposes. Tu et al. in U.S. Pat. No. 6,283,962 discloses a medical ablation for treating valvular annulus wherein an elongate tubular element comprises an electrode disposed at its distal section that is extendible from an opening at one side of the tubular element, the energy generator, and means for generating rotational sweeping force at the distal section of the tubular element to effect the heat treatment and the rotational sweeping massage therapy for target tissues. Both patents, entire contents of which are incorporated herein by reference, teach only the local tissue shrinkage, not for treating simultaneously a substantial portion of the valvular annulus.

"U.S. Pat. No. 6,402,781 issued on Jun. 11, 2002, entire contents of which are incorporated herein by reference, discloses a mitral annuloplasty and left ventricle restriction device designed to be transvenously advanced and deployed within the coronary sinus and in some embodiments other coronary veins. The device places tension on adjacent structures, reducing the diameter and/or limiting expansion of the mitral annulus and/or limiting diastolic expansion of the left ventricle.

"Hissong in U.S. Pat. No. 6,361,531 issued Mar. 26, 2002, entire contents of which are incorporated herein by reference, discloses focused ultrasound ablation device having malleable handle shafts. A remote energy source, such as ultrasound or microwave energy, can be emitted wirelessly to a focused target tissue located away from the ultrasound device. However, it is not disclosed for focused ultrasound energy for repairing a mitral valve or an atrioventricular valve annulus.

"Therefore, there is a clinical need to have a percutaneous, or less invasive catheter or cannula-based approach as well as a surgical hand-held device for repairing an annular organ structure of a heart valve, a valve leaflet, chordae tendinae, papillary muscles, and the tissue defect by using high frequency energy (RF, microwave or ultrasound) for reducing and/or shrinking a tissue mass, with optionally an injected heat shrinkable biomaterial along with the host tissue mass for tightening and stabilizing the dilated tissue adjacent a valvular annulus. There is also a clinical need for an improved apparatus system having capabilities of measuring a contact force at the point of contact with the tissue to be treated, as disclosed by one of inventors in U.S. Pat. No. 6,113,593, entire contents which are incorporated herein by reference."

Supplementing the background information on this patent, NewsRx reporters also obtained the inventors' summary information for this patent: "In general, it is an object of the present invention to provide a medical system and methods for repairing an annular organ structure of a heart valve, an annular organ structure of a venous valve, a valve leaflet, chordae tendinae, papillary muscles, a sphincter, and the like. The system may be deployed into the heart via a catheter percutaneously or via a cannula through a percutaneous intercostal penetration (minimally invasive) or with a surgical hand-held device during an open chest procedure. The system may be deployed into a sphincter via trans thoracic or trans abdominal approaches or via urogenital or gastrointestinal orifices. The system may be deployed into a venous valve using local surgical approaches or by percutaneous access into the venous system. The effective tissue-shrinkable energy may be applied at a distance wirelessly from the target annular organ sufficient to shrink and tighten the target organ structure.

"It is another object of the present invention to provide a catheter, cannula or surgical system and methods by using cryoablation energy, radiofrequency energy, or high frequency current for tissue treatment or repairing and causing the tissue to shrink or tighten. The high frequency energy may include radiofrequency, focused ultrasound, infrared, or microwave energy, wherein the high, frequent focused current is applied noninvasively from outside of a body.

"It is still another object to provide a catheter-based less invasive system that intimately contacts the tissue of an annulus in order to tighten and stabilize a substantial portion of the dysfunctional annular organ structure simultaneously or sequentially. The step of intimately contacting may be assisted by a needles penetrating system or a suction ports system for anchoring the energy-releasing elements.

"It is still another aspect of the present invention to provide a catheter-based less invasive system that transmits an effective amount of the high frequency ultrasound or microwave current energy through a medium tissue onto the target annulus in order to tighten and stabilize a substantial portion of the dysfunctional annular organ structure. In one embodiment, the catheter with a distal ultrasound transducer is placed inside a coronary vein.

"It is a general aspect of the present invention to provide a method for repairing a valvular annulus defect comprising locating the valvular annulus defect via a plurality of ultrasound signals emitted from a catheter as auxiliary locating means; and applying remotely effective tissue-shrinkable energy sufficient to treat the valvular annulus by focusing the energy at about the annulus defect.

"It is a preferred object to provide a method for repairing a valvular annulus defect comprising injecting a heat shapeable biomaterial formulated for in vivo administration by injection via a delivery system at a site of the valvular annulus defect; and applying heat sufficient to shape the biomaterial and immobilize the biomaterial at about the annulus defect.

"It is another preferred object of the present invention to provide a flexible tissue-contactor member located at the distal tip section of a catheter shaft for compressively sandwiching and contacting an inner wall of an annular organ structure, wherein the tissue-contactor member includes an expandable structure having a narrow middle region and enlarged end regions that is generally configured to snugly fit and sandwich the inner wall of an annular organ structure for optimal therapy that is characterized by exerting compression onto the inner wall.

"It is another object of the invention to provide a method for repairing a tissue defect comprising: injecting a heat shapeable biomaterial formulated for in vivo administration by injection via a percutaneous delivery system at a site of the tissue defect; and applying heat to the biomaterial and a portion of the tissue defect adapted for shaping the biomaterial, the heat being below a temperature sufficient for effecting crosslinking of the biomaterial and the portion of the tissue defect. In one embodiment, the tissue contact side is provided with a dual ablation capability of RF and ultrasound energy. In another embodiment, the biomaterial acts as an annular support and is biodegradable. Heat applied to the biomaterial will cause shape changes to the host annulus. In yet another embodiment, the heat is provided by RF, ultrasound, microwave, infrared or combination thereof.

"It is still another object of the present invention to provide a catheter system and methods for providing high frequency current energy to the tissue needed for treatment at or adjacent to an annular organ structure. In one embodiment, the catheter system is placed remotely from and/or non-contacting with the target tissue. In another embodiment, it is provided a catheter having a working distal end that is covered by a plurality of adjacent filaments which are bound together by suturing, braiding, jacketing or encapsulating to provide a non-skid surface.

"In one embodiment, the method for operating a catheter system for repairing a valvular annulus or a valveless annulus comprising compressively sandwiching the annulus by a tissue-contactor member and delivering high frequency energy to the annulus, wherein the tissue-contactor member is configured to have a narrow middle region between an enlarged distal region and an enlarged proximal region adapted for compressively sandwiching the annulus at about the middle region for subsequent tissue treatment.

"It is still another object of the present invention to provide a catheter system and methods for providing high frequency current to a restriction device, possibly biodegradable, designed to be transversely advanced and deployed within the cardiac vein via the coronary sinus and in some embodiments other coronary veins. This device, when heated, will place tension on adjacent structures, reducing the diameter and/or limiting the expansion of the mitral annulus and/or diastolic expansion of the left ventricle.

"It is another preferred object of the present invention to provide a magnetic system for position the energy producing members of the catheter system and to secure the position once it is in place. One embodiment would consist of a single magnet or a series of magnets embedded in the catheter in or near the energy producing electrode. An opposing catheter with a single magnet or a series of magnets would be placed either in a coronary vein, inside a heart chamber, outside the heart, or outside the body. The two catheters would line magnetically to position the energy producing catheter over or near the annulus and hold it in place.

"It is a general aspect of the present invention to provide a method for repairing a valvular annulus defect comprising locating the valvular annulus defect via a plurality of ultrasound signals emitted from a catheter as auxiliary locating means; and applying remotely effective tissue-shrinkable energy sufficient to treat the valvular annulus by focusing the energy at about the annulus defect.

"The catheter system of the present invention has several significant advantages over known catheters or ablation techniques for repairing an annular organ structure of a heart valve, a valve leaflet, chordae tendinae, papillary muscles, venous valve, sphincter, and the like. In particular, the ablation catheter of this invention by using high frequency current energy for reducing and/or shrinking a tissue mass may tighten and stabilize the dilated tissue at or adjacent a valvular annulus."

For the URL and additional information on this patent, see: Witzel, Thomas; Hauck, Wallace N; Osth, John A.; Tu, Hosheng. Method for Treating and Repairing Mitral Valve Annulus. U.S. Patent Number 8328798, filed May 15, 2007, and issued December 11, 2012. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser'Sect1=PTO2&Sect2=HITOFF&p=92&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=4579&f=G&l=50&co1=AND&d=PTXT&s1=20121211.PD.&OS=ISD/20121211&RS=ISD/20121211

Keywords for this news article include: Veins, Surgery, Systole, Therapy, Diastole, Angiology, Technology, Prosthetics, Heart Valves, Legal Issues, Mitral Valve, Cardio Device, Venous Valves, Quantumcor Inc, Catheter System, Medical Devices, Pulmonary Valve, Tricuspid Valve, Myocardial Contraction, Cardiovascular Physiological Phenomena.

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