Abstract:
The present invention relates to minimally invasive methods and apparatus for performing annuloplasty. According to one aspect of the present invention, a method for performing annuloplasty includes creating a first plication in the tissue near a mitral valve of a heart, using at least a first plication element, and creating a second plication in the tissue near the mitral valve such that the second plication is substantially coupled to the first plication. In another aspect, an apparatus for performing annuloplasty includes a distal catheter portion having a sidewall defining a lumen, anchor delivery structure disposed in the lumen, and al least one anchor supported on the anchor delivery structure. The anchor delivery structure is movable from a first position wherein the anchor is disposed within the lumen, to a second position wherein the anchor is moved through an opening.

Description:
The present invention claims priority of U.S. Provisional Patent Application No. 60/420,095, filed Oct. 21, 2002, which is hereby incorporated by reference in its entirety. 
     CROSS REFERENCE TO RELATED APPLICATIONS 
     The present invention is related to U.S. Pat. No. 6,619,291 entitled “Method and Apparatus for Catheter-Based Annuloplasty,” filed Apr. 24, 2001 and issued Sep. 16, 2003, and to co-pending U.S. patent application Ser. No. 09/866,550, entitled “Method and Apparatus for Catheter-Based Annuloplasty Using Local Plications, which are each incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates generally to techniques for treating mitral valve insufficiencies such as mitral valve leakage. More particularly, the present invention relates to systems and methods for treating a leaking mitral valve in a minimally invasive manner. 
     2. Description of the Related Art 
     Congestive heart failure (CHF), which is often associated with an enlargement of the heart, is a leading cause of death. As a result, the market for the treatment of CHF is becoming increasingly prevalent. For instance, the treatment of CHF is a leading expenditure of Medicare and Medicaid dollars in the United States of America. Typically, the treatment of CHF enables many who suffer from CHF to enjoy an improved quality of life. 
     Referring initially to  FIG. 1 , the anatomy of a heart, specifically the left side of a heart, will be described. The left side of a heart  104  includes a left atrium  108  and a left ventricle  112 . An aorta  114  receives blood from left ventricle  112  through an aortic valve  120 , which serves to prevent regurgitation of blood back into left ventricle  112 . A mitral valve  116  is disposed between left atrium  108  and left ventricle  112 , and effectively controls the flow of blood between left atrium  108  and left ventricle  112 . 
     Mitral valve  116 , which will be described below in more detail with respect to  FIG. 2   a , includes an anterior leaflet and a posterior leaflet that are coupled to cordae tendonae  124  which serve as “tension members” that prevent the leaflets of mitral valve  116  from opening indiscriminately. When left ventricle  112  contracts, cordae tendonae  124  allow the anterior leaflet to open upwards until limited in motion by cordae tendonae  124 . Normally, the upward limit of opening corresponds to a meeting of the anterior and posterior leaflets and the prevention of backflow. Cordae tendonae  124  arise from a columnae carnae  128  or, more specifically, a musculi papillares of columnae carnae  128 . 
     Left ventricle  112  includes trabeculae  132  which are fibrous cords of connective tissue that are attached to wall  134  of left ventricle  112 . Trabeculae  132  are also attached to an interventricular septum  136  which separates left ventricle  112  from a right ventricle (not shown) of heart  104 . Trabeculae  132  are generally located in left ventricle  112  below columnae carnae  128 . 
       FIG. 2   a  is a cut-away top-view representation of mitral valve  116  and aortic valve  120 . Aortic valve  120  has a valve wall  204  that is surrounded by a skeleton  208   a  of fibrous material. Skeleton  208   a  may generally be considered to be a fibrous structure that effectively forms a ring around aortic valve  120 . A fibrous ring  208   b , which is substantially the same type of structure as skeleton  208   a , extends around mitral valve  116 . Mitral valve  116  includes an anterior leaflet  212  and a posterior leaflet  216 , as discussed above. Anterior leaflet  212  and posterior leaflet  216  are generally thin, flexible membranes. When mitral valve  116  is closed (as shown in  FIG. 2   a ), anterior leaflet  212  and posterior leaflet  216  are generally aligned and contact one another to create a seal. Alternatively, when mitral valve  116  is opened, blood may flow through an opening created between anterior leaflet  212  and posterior leaflet  216 . 
     Many problems relating to mitral valve  116  may occur and these insufficiencies may cause many types of ailments. Such problems include, but are not limited to, mitral regurgitation. Mitral regurgitation, or leakage, is the backflow of blood from left ventricle  112  into the left atrium  108  due to an imperfect closure of mitral valve  116 . That is, leakage often occurs when a gap is created between anterior leaflet  212  and posterior leaflet  216 . 
     In general, a relatively significant gap may exist between anterior leaflet  212  and posterior leaflet  216  (as shown in  FIG. 2   b ) for a variety of different reasons. For example, a gap may exist due to congenital malformations, because of ischemic disease, or because a heart has been damaged by a previous heart attack. A gap may also be created when congestive heart failure, e.g., cardiomyopathy, or some other type of distress causes a heart to be enlarged. When a heart is enlarged, the walls of the heart, e.g., wall  134  of a left ventricle, may stretch or dilate, causing posterior leaflet  216  to stretch. It should be appreciated that anterior leaflet  212  generally does not stretch. As shown in  FIG. 2   b , a gap  220  between anterior leaflet  212  and stretched posterior leaflet  216 ′ is created when wall  134 ′ stretches. Hence, due to the existence of gap  220 , mitral valve  116  is unable to close properly, and may begin to leak. 
     Leakage through mitral valve  116  generally causes a heart to operate less efficiently, as the heart must work harder to maintain a proper amount of blood flow therethrough. Leakage through mitral valve  116 , or general mitral insufficiency, is often considered to be a precursor to CHF. There are generally different levels of symptoms associated with heart failure. Such levels are classified by the New York Heart Association (NYHA) functional classification system. The levels range from a Class 1 level which is associated with an asymptomatic patient who has substantially no physical limitations to a Class 4 level which is associated with a patient who is unable to carry out any physical activity without discomfort, and has symptoms of cardiac insufficiency even at rest. In general, correcting for mitral valve leakage may be successful in allowing the NYHA classification grade of a patient to be reduced. For instance, a patient with a Class 4 classification may have his classification reduced to Class 3 and, hence, be relatively comfortable at rest. 
     Treatments used to correct for mitral valve leakage or, more generally, CHF, are typically highly invasive, open-heart surgical procedures. Ventricular assist devices such as artificial hearts may be implanted in a patient whose own heart is failing. The implantation of a ventricular assist device is often expensive, and a patient with a ventricular assist device must be placed on extended anti-coagulant therapy. As will be appreciated by those skilled in the art, anti-coagulant therapy reduces the risk of blood clots being formed, as for example, within the ventricular assist device. While reducing the risks of blood clots associated with the ventricular assist device is desirable, anti-coagulant therapies may increase the risk of uncontrollable bleeding in a patient, e.g., as a result of a fall, which is not desirable. 
     Rather than implanting a ventricular assist device, bi-ventricular pacing devices similar to pace makers may be implanted in some cases, e.g., cases in which a heart beats inefficiently in a particular asynchronous manner. While the implantation of a bi-ventricular pacing device may be effective, not all heart patients are suitable for receiving a bi-ventricular pacing device. Further, the implantation of a bi-ventricular pacing device is expensive. 
     Open-heart surgical procedures which are intended to correct for mitral valve leakage, specifically, involve the implantation of replacement valves. Valves from animals, e.g., pigs, may be used to replace a mitral valve  116  in a human. While the use of a pig valve may relatively successfully replace a mitral valve, such valves generally wear out, thereby requiring additional open surgery at a later date. Mechanical valves, which are less likely to wear out, may also be used to replace a leaking mitral valve. However, when a mechanical valve is implanted, there is an increased risk of thromboembolism, and a patient is generally required to undergo extended anti-coagulant therapies. 
     A less invasive surgical procedure involves heart bypass surgery associated with a port access procedure. For a port access procedure, the heart may be accessed by cutting a few ribs, as opposed to opening the entire chest of a patient. In other words, a few ribs may be cut in a port access procedure, rather than opening a patient&#39;s sternum. 
     One open-heart surgical procedure that is particularly successful in correcting for mitral valve leakage and, in addition, mitral regurgitation, is an annuloplasty procedure. During an annuloplasty procedure, an annuloplasty ring may be implanted on the mitral valve to cause the size of a stretched mitral valve  116  to be reduced to a relatively normal size.  FIG. 3  is a schematic representation of an annuloplasty ring. An annuloplasty ring  304  is shaped approximately like the contour of a normal mitral valve. That is, annuloplasty ring  304  is shaped substantially like the letter “D.” Typically, annuloplasty ring  304  may be formed from a rod or tube of biocompatible material, e.g., plastic, that has a DACRON mesh covering. 
     In order for annuloplasty ring  304  to be implanted, a surgeon surgically attaches annuloplasty ring  304  to the mitral valve on the atrial side of the mitral valve. Conventional methods for installing ring  304  require open-heart surgery which involve opening a patient&#39;s sternum and placing the patient on a heart bypass machine. As shown in  FIG. 4 , annuloplasty ring  304  is sewn to a posterior leaflet  318  and an anterior leaflet  320  of a top portion of mitral valve  316 . In sewing annuloplasty ring  304  onto mitral valve  316 , a surgeon generally alternately acquires a relatively large amount of tissue from mitral tissue, e.g., a one-eighth inch bite of tissue, using a needle and thread, followed by a smaller bite from annuloplasty ring  304 . Once a thread has loosely coupled annuloplasty ring  304  to mitral valve tissue, annuloplasty ring  304  is slid onto mitral valve  316  such that tissue that was previously stretched out, e.g., due to an enlarged heart, is effectively pulled in using tension applied by annuloplasty ring  304  and the thread which binds annuloplasty ring  304  to the mitral valve tissue. As a result, a gap, such as gap  220  of  FIG. 2   b , between anterior leaflet  320  and posterior leaflet  318  may be substantially closed off. After the mitral valve is shaped by ring  304 , the anterior and posterior leaflets  320 ,  318  will reform to create a new contact line and will enable mitral valve  318  to appear and to function as a normal mitral valve. 
     Once implanted, tissue generally grows over annuloplasty ring  304 , and a line of contact between annuloplasty ring  304  and mitral valve  316  will essentially enable mitral valve  316  to appear and function as a normal mitral valve. Although a patient who receives annuloplasty ring  304  may be subjected to anti-coagulant therapies, the therapies are not extensive, as a patient is only subjected to the therapies for a matter of weeks, e.g., until tissue grows over annuloplasty ring  304 . 
     A second surgical procedure which is generally effective in reducing mitral valve leakage involves placing a single edge-to-edge suture in the mitral valve. With reference to  FIG. 5   a , such a surgical procedure, e.g., an Alfieri stitch procedure or a bow-tie repair procedure, will be described. An edge-to-edge stitch  404  is used to stitch together an area at approximately the center of a gap  408  defined between an anterior leaflet  420  and a posterior leaflet  418  of a mitral valve  416 . Once stitch  404  is in place, stitch  404  is pulled in to form a suture which holds anterior leaflet  420  against posterior leaflet  418 , as shown. By reducing the size of gap  408 , the amount of leakage through mitral valve  416  may be substantially reduced. 
     Although the placement of edge-to-edge stitch  404  is generally successful in reducing the amount of mitral valve leakage through gap  408 , edge-to-edge stitch  404  is conventionally made through open-heart surgery. In addition, the use of edge-to-edge stitch  404  is generally not suitable for a patient with an enlarged, dilated heart, as blood pressure causes the heart to dilate outward, and may put a relatively large amount of stress on edge-to-edge stitch  404 . For instance, blood pressure of approximately 120/80 or higher is typically sufficient to cause the heart to dilate outward to the extent that edge-to-edge stitch  404  may become undone, or tear mitral valve tissue. 
     Another surgical procedure which reduces mitral valve leakage involves placing sutures along a mitral valve annulus around the posterior leaflet. A surgical procedure which places sutures along a mitral valve with be described with respect to  FIG. 5   b . Sutures  504  are formed along an annulus  540  of a mitral valve  516  around a posterior leaflet  518  of mitral valve  516 , and may be formed as a double track, e.g., in two “rows,” from a single strand of suture material. Sutures  504  are tied off at approximately a central point  506  of posterior leaflet  518 . Pledgets  546  are often positioned under selected sutures  504 , e.g., at central point  506 , to prevent sutures  504  from tearing through annulus  540 . When sutures  504  are tied off, annulus  540  may effectively be tightened to a desired size such that the size of a gap  508  between posterior leaflet  518  and an anterior leaflet  520  may be reduced. 
     The placement of sutures  504  along annulus  540 , in addition to the tightening of sutures  504 , is generally successful in reducing mitral valve leakage. However, the placement of sutures  504  is conventionally accomplished through open-heart surgical procedures. That is, like other conventional procedures, a suture-based annuloplasty procedure is invasive. 
     While invasive surgical procedures have proven to be effective in the treatment of mitral valve leakage, invasive surgical procedures often have significant drawbacks. Any time a patient undergoes open-heart surgery, there is a risk of infection. Opening the sternum and using a cardiopulmonary bypass machine has also been shown to result in a significant incidence of both short and long term neurological deficits. Further, given the complexity of open-heart surgery, and the significant associated recovery time, people who are not greatly inconvenienced by CHF symptoms, e.g., people at a Class 1 classification, may choose not to have corrective surgery. In addition, people who most need open heart surgery, e.g., people at a Class 4 classification, may either be too frail or too weak to undergo the surgery. Hence, many people who may benefit from a surgically repaired mitral valve may not undergo surgery. 
     Therefore, what is needed is a minimally invasive treatment for mitral valve leakage. Specifically, what is desired is a method for reducing leakage between an anterior leaflet and a posterior leaflet of a mitral valve that does not require conventional surgical intervention. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a non-invasive method of performing annuloplasty. Performing an annuloplasty on a mitral valve by accessing the left ventricle of the heart, as for example using a catheter, enables complicated surgical procedures to be avoided when treating mitral valve leakage. Avoiding open-heart surgical procedures generally makes annuloplasty more accessible to patients who may benefit from annuloplasty. As mitral valve leakage is often considered to be an early indicator of congestive heart failure, a minimally invasive annuloplasty procedure that corrects for leakage problems, such as one which involves positioning discrete plications in fibrous tissue around the mitral valve, may greatly improve the quality of life of many patients who might not be suitable for invasive annuloplasty procedures. 
     According to one aspect of the present invention, a method for performing annuloplasty includes creating a first plication in the tissue near a mitral valve of a heart, using at least a first plication element, and creating a second plication in the tissue near the mitral valve such that the second plication is substantially coupled to the first plication. In one embodiment, the method also includes accessing a left ventricle of the heart to provide the first plication element to the left ventricle, and engaging the first plication element to the tissue near the mitral valve. Engaging the first plication element includes causing the first plication element to substantially pass through a portion of the tissue to substantially anchor the first plication element to the tissue near the mitral valve. 
     According to another aspect of the present invention, a method for performing annuloplasty includes accessing a heart to provide a plurality of plication elements to the heart. The plurality of plication elements are provided to the heart through a catheter arrangement, and include a first anchor arrangement. The method also includes engaging the first anchor arrangement to tissue near a mitral valve of the heart using the catheter arrangement by causing the first anchor arrangement to substantially pass through the tissue to substantially anchor the first anchor arrangement to the tissue near the mitral valve. Finally, the method includes creating at least a first plication and a second plication using the first anchor arrangement. 
     In accordance with still another embodiment of the present invention, a method for performing annuloplasty includes accessing an area of a heart to provide a first plication element to the area using a catheter arrangement which has a first portion and a second portion, and substantially anchoring the first portion of the catheter arrangement to tissue near a mitral valve of the heart. The method further includes positioning a tip of the second portion of the catheter arrangement at a first distance from the first portion, and substantially engaging the first anchor to the tissue near the mitral valve of the heart using the second portion of the catheter arrangement. Substantially engaging the first anchor includes causing the first anchor to substantially pass through a portion of the tissue to substantially anchor the first anchor to the tissue near the mitral valve using the second portion of the catheter arrangement. In one embodiment, substantially anchoring the first portion of the catheter arrangement to tissue near the mitral valve of the heart includes positioning the first portion of the catheter arrangement over a guide that is at least temporarily anchored to the tissue near the mitral valve. 
     These and other advantages of the present invention will become apparent upon reading the following detailed descriptions and studying the various figures of the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a cross-sectional front-view representation of the left side of a human heart. 
         FIG. 2   a  is a cut-away top-view representation of the mitral valve and the aortic valve of  FIG. 1 . 
         FIG. 2   b  is a cut-away representation of a stretched mitral valve and an aortic valve. 
         FIG. 3  is a representation of an annular ring that is suitable for use in performing a conventional annuloplasty procedure. 
         FIG. 4  is a representation of a mitral valve and an aortic valve after the annular ring of  FIG. 3  has been implanted. 
         FIG. 5   a  is a representation of a mitral valve and an aortic valve after a single edge-to-edge suture has been applied to reduce mitral regurgitation. 
         FIG. 5   b  is a representation of a mitral valve and an aortic valve after sutures along a mitral valve annulus have been applied to reduce mitral regurgitation. 
         FIG. 6   a  is a representation of a delivery tube and a J-catheter in accordance with an embodiment of the present invention. 
         FIG. 6   b  is a cut-away front view of the left side of a heart in which the delivery tube and the J-catheter of  FIG. 6   a  have been inserted in accordance with an embodiment of the present invention. 
         FIG. 7   a  is a representation of a catheter assembly in accordance with an embodiment of the present invention. 
         FIG. 7   b  is a cross-sectional representation of the catheter assembly of  FIG. 7   a  in accordance with an embodiment of the present invention. 
         FIG. 7   c  is a cut-away top-view representation of a left ventricle in which the gutter catheter of  FIGS. 7   a  and  7   b  has been positioned in accordance with an embodiment of the present invention. 
         FIG. 8  is a cut-away top-view representation of a left ventricle in which a guide wire has been positioned in accordance with an embodiment of the present invention. 
         FIG. 9   a  is a cut-away top-view representation of a left ventricle of the heart in which local plication suture structures have been implanted in accordance with an embodiment of the present invention. 
         FIG. 9   b  is a cut-away top-view representation of a left ventricle of the heart in which local plication suture structures which are coupled have been implanted in accordance with an embodiment of the present invention. 
         FIG. 10   a  is a representation of a suture structure after T-bars have been introduced to an atrial side of a mitral valve through fibrous tissue near the mitral valve in accordance with an embodiment of the present invention. 
         FIG. 10   b  is a representation of the suture structure of  FIG. 10   a  after the T-bars have been engaged to the fibrous tissue in accordance with an embodiment of the present invention. 
         FIG. 11  is a representation of a suture structure which includes a locking element with a spring in accordance with an embodiment of the present invention. 
         FIG. 12   a  is a representation of a suture structure which includes a locking element with a resorbable component in accordance with an embodiment of the present invention. 
         FIG. 12   b  is a representation of the suture structure of  FIG. 12   a  after the resorbable component has degraded in accordance with an embodiment of the present invention. 
         FIG. 12   c  is a representation of the suture structure of  FIG. 12   b  after a plication has been created in accordance with an embodiment of the present invention. 
         FIG. 13   a  is a representation of a first catheter which is suitable for use in delivering and implementing a suture structure in accordance with an embodiment of the present invention. 
         FIG. 13   b  is a representation of a second catheter which is suitable for use in delivering and implementing a suture structure in accordance with an embodiment of the present invention. 
         FIG. 13   c  is a representation of a third catheter assembly which is suitable for use in delivering and implementing a suture structure in accordance with an embodiment of the present invention. 
         FIGS. 14   a  and  14   b  are a process flow diagram which illustrates the steps associated with one method of performing annuloplasty using a suture structure and a catheter in accordance with an embodiment of the present invention. 
         FIG. 15  is a cut-away top-view representation of a left ventricle of the heart in which local plication elements have been implanted in accordance with an embodiment of the present invention. 
         FIG. 16   a  is a representation of a local plication element which has spring-like characteristics in accordance with an embodiment of the present invention. 
         FIG. 16   b  is a representation of the local plication element of  FIG. 16   a  after forces have been applied to open the local plication element in accordance with an embodiment of the present invention. 
         FIG. 16   c  is a representation of the local plication element of  FIG. 16   b  after tips of the local plication element pierce through tissue in accordance with an embodiment of the present invention. 
         FIG. 16   d  is a representation of the local plication element of  FIG. 16   c  after the tips of the local plication element engage the tissue to form a local plication in accordance with an embodiment of the present invention. 
         FIG. 17   a  is a representation of a local plication element, which is formed from a shape memory material, in an open state in accordance with an embodiment of the present invention. 
         FIG. 17   b  is a representation of the local plication element of  FIG. 17   a  in a closed state in accordance with an embodiment of the present invention. 
         FIG. 18   a  is a representation of a first self-locking clip which is suitable for use in forming a local plication in accordance with an embodiment of the present invention. 
         FIG. 18   b  is a representation of a second self-locking clip which is suitable for use in forming a local plication in accordance with an embodiment of the present invention. 
         FIG. 19  is a representation of a plication-creating locking mechanism in accordance with an embodiment of the present invention. 
         FIG. 20   a  is a representation of the plication-creating locking mechanism of  FIG. 19  as provided within the left ventricle of a heart in accordance with an embodiment of the present invention. 
         FIG. 20   b  is a representation of the plication-creating locking mechanism of  FIG. 20   a  after forces have been applied to cause tines of the mechanism to contact tissue in accordance with an embodiment of the present invention. 
         FIG. 20   c  is a representation of the plication-creating locking mechanism of  FIG. 20   b  after tissue has been gathered between the tines of the mechanism in accordance with an embodiment of the present invention. 
         FIG. 20   d  is a representation of the plication-creating locking mechanism of  FIG. 20   c  after a local plication has been formed in accordance with an embodiment of the present invention. 
         FIGS. 21   a  and  21   b  are a process flow diagram which illustrates the steps associated with one method of performing annuloplasty using a local plication element and a catheter in accordance with an embodiment of the present invention. 
         FIG. 22   a  is a cut-away front view of the left side of a heart in which an L-shaped catheter has been inserted in accordance with an embodiment of the present invention. 
         FIG. 22   b  is a cut-away front view of the left side of a heart in which an L-shaped catheter has been inserted and extended in accordance with an embodiment of the present invention. 
         FIG. 22   c  is a cut-away front view of the left side of a heart in which an L-shaped catheter has been inserted, extended, and curved in accordance with an embodiment of the present invention. 
         FIG. 23   a  is representation of a portion of a first catheter which may use suction to engage against tissue in accordance with an embodiment of the present invention. 
         FIG. 23   b  is representation of a portion of a first catheter which may use suction to engage against tissue in accordance with an embodiment of the present invention. 
         FIG. 24   a  is representation of a portion of a wire with a helical coil which may be used as a temporary anchor in accordance with an embodiment of the present invention. 
         FIG. 24   b  is representation of a portion of a catheter with a helical coil which may be used as a temporary anchor in accordance with an embodiment of the present invention. 
         FIG. 25  is a representation of an anchor which is deployed and anchored into tissue in accordance with an embodiment of the present invention. 
         FIG. 26   a  is a representation of a portion of an incrementor catheter in a closed configuration which is positioned over a tail of an anchor in accordance with an embodiment of the present invention. 
         FIG. 26   b  is a representation of a portion of an incrementor catheter in an open configuration which is positioned over a tail and is extended such that a first section and a second section of the incrementor have tips that are separated by a distance in accordance with an embodiment of the present invention. 
         FIG. 27  is a representation of two anchors which may be used to create a plication in accordance with an embodiment of the present invention. 
         FIGS. 28   a - f  are representations of anchors and lockers which are used in a process of creating a daisy chain of plications in accordance with an embodiment of the present invention. 
         FIG. 29   a  is a cut-away front view of the left side of a heart in which a hook catheter has been inserted in accordance with an embodiment of the present invention. 
         FIG. 29   b  is a cut-away front view of the left side of a heart in which a hook catheter is positioned beneath a mitral valve in accordance with an embodiment of the present invention. 
         FIG. 29   c  is a cut-away front view of the left side of a heart in which a temporary anchor has been inserted in accordance with an embodiment of the present invention. 
         FIG. 29   d  is a cut-away front view of the left side of a heart in which a hook catheter which carries a permanent anchor is inserted in accordance with an embodiment of the present invention. 
         FIG. 29   e  is a cut-away front view of the left side of a heart in which a permanent anchor has been inserted in accordance with an embodiment of the present invention. 
         FIG. 29   f  is a cut-away front view of the left side of a heart in which an incrementor catheter has been inserted in accordance with an embodiment of the present invention. 
         FIG. 29   g  is a cut-away front view of the left side of a heart in which two permanent anchors have been inserted in accordance with an embodiment of the present invention. 
         FIG. 29   h  is a cut-away front view of the left side of a heart in which two permanent anchors and a locking device or locker have been inserted in accordance with an embodiment of the present invention. 
         FIG. 30  is a process flow diagram which illustrates the steps associated with one method of creating a plication using an incrementor catheter in accordance with an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Invasive, open-heart surgical procedures are generally effective in the treatment of mitral valve leakage. However, open-heart surgical procedures may be particularly hazardous to some patients, e.g., frail patients or patients who are considered as being very ill, and undesirable to other patients, e.g., patients who are asymptomatic and do not wish to undergo a surgical procedure. As such, open-heart surgical procedures to correct mitral valve leakage or, more generally, mitral valve insufficiency, are not suitable for many patients who would likely benefit from reducing or eliminating the mitral valve leakage. 
     A catheter-based annuloplasty procedure enables annuloplasty to be performed on a patient without requiring that the patient undergo open-heart surgery, or be placed on cardiopulmonary bypass. Catheters may be introduced into the left ventricle of a heart through the aorta to position a guide wire and plication implants on the ventricular side of a mitral valve, i.e., under a mitral valve. Catheters may also be used to couple the plication implants to fibrous tissue associated with the skeleton of the heart around the mitral valve. 
     The use of catheters to perform an annuloplasty procedure by delivering and engaging plication implants or structures enables the annuloplasty procedure to be performed without open-heart surgery, and without a bypass procedure. Recovery time associated with the annuloplasty, as well as the risks associated with annuloplasty, may be substantially minimized when the annuloplasty is catheter-based. As a result, annuloplasty becomes a more accessible procedure, since many patients who might previously not have received treatment for mitral valve leakage, e.g., frail patients and asymptomatic patients, may choose to undergo catheter-based annuloplasty. 
     To begin a catheter-based annuloplasty procedure, a delivery tube and a J-catheter may be inserted into a left ventricle of the heart through the aorta. Inserting the delivery tube and the J-catheter through the aorta enables the left ventricle of the heart to be reached substantially without coming into contact with trabeculae or the cordae tendonae in the left ventricle.  FIG. 6   a  is a diagrammatic representation of a delivery tube and a J-catheter in accordance with an embodiment of the present invention. Delivery tube  604  has a substantially circular cross section, and is configured to receive a J-catheter  608 . J-catheter  608  is arranged to move longitudinally through and opening in delivery tube  604  as needed. 
     In general, delivery tube  604  is an elongated body which may be formed from a flexible, durable, biocompatible material such as nylon, urethane, or a blend of nylon and urethane, e.g., PEBAX®. Likewise, J-catheter  608 , which is also an elongated body, may also be formed from a biocompatible material. A material used to form J-catheter  608  is typically also relatively flexible. In the described embodiment, a tip of J-catheter  608  is rigid enough to allow the tip of J-catheter  608  to maintain a relatively curved shape, e.g., a “J” shape. The curve in J-catheter  608  is configured to facilitate the positioning of a gutter catheter, as will be described below with respect to  FIGS. 7   a - c.    
       FIG. 6   b  is a schematic representation of delivery tube  604  and J-catheter  608  positioned within a heart in accordance with an embodiment of the present invention. As shown, after delivery tube  604  and J-catheter  608  are effectively “snaked” or inserted through a femoral artery, portions of delivery tube  604  and of J-catheter  608  are positioned within an aorta  620  of a heart  616 . A tip  626  of J-catheter  608 , which is substantially oriented at a right angle from the body of J-catheter  608 , and an end of delivery tube  604  are oriented such that they pass through an aortic valve  630 . Hence, an end of delivery tube  604  and tip  626  are positioned at a top portion of left ventricle  624 , where wall  632  of left ventricle  624  is relatively smooth. The relative smoothness of the top portion of left ventricle  624  enables a catheter to be properly positioned within left ventricle  624  by guiding the tip of the catheter along wall  632 . In one embodiment, tip  626  is oriented such that it is positioned approximately just below a mitral valve  628  on the ventricular side of mitral valve  628 . 
     Once positioned within left ventricle  624 , J-catheter  608  may be rotated within delivery tube  604  such that tip  626  is may enable a gutter catheter fed therethrough to run along the contour of wall  632 . Typically, the gutter catheter runs along the contour of wall  632  in an area that is effectively defined between a plane associated with papillary muscles  640 , a plane associated with the posterior leaflet of mitral valve  628 , cordae tendonae  642 , and wall  632 . A “gutter” is located in such an area or region and, more specifically, is positioned substantially right under mitral valve  628  where there is a relatively insignificant amount of trabeculae. 
     With reference to  FIGS. 7   a - 7   c , a gutter catheter will be described in accordance with an embodiment of the present invention. A gutter catheter  704 , which is part of a catheter assembly  702  as shown in  FIG. 7   a , is arranged to be extended through J-catheter  626  such that gutter catheter  704  may be steered within a left ventricle just beneath a mitral valve. Gutter catheter  704 , which may include a balloon tip (not shown), is typically formed from a flexible material such as nylon, urethane, or PEBAX®. In one embodiment, gutter catheter  704 , which is steerable, may be formed using a shape memory material. 
     As shown in  FIG. 7   a  and  FIG. 7   b , which represents a cross section of catheter assembly  702  taken at a location  710 , gutter catheter  704  is at least partially positioned within J-catheter  608  which, in turn, is at least partially positioned within delivery tube  604 . Gutter catheter  704  may be free to rotate within and extend through J-catheter  608 , while J-catheter  608  may be free to rotate within and extend through delivery tube  604 . 
     Referring next to  FIG. 7   c , the positioning of gutter catheter  704  within a left ventricle of the heart will be described in accordance with an embodiment of the present invention. It should be appreciated that the representation of gutter catheter  704  within a left ventricle  720  has not been drawn to scale, for ease of illustration and ease of discussion. For instance, the distance between a wall  724  of left ventricle  720  and a mitral valve  728  has been exaggerated. In addition, it should also be appreciated that the positioning of delivery tube  604  and, hence, J-catheter  608  and gutter catheter  704  within aortic valve  732  may vary. 
     Gutter catheter  704  protrudes through tip  626  of J-catheter  608 , and, through steering, essentially forms an arc shape similar to that of mitral valve  728  along the contour of a wall  724  of left ventricle  720  just beneath mitral valve  728 , i.e., along the gutter of left ventricle  720 . Wall  724  of left ventricle  720  is relatively smooth just beneath mitral valve  728 , i.e., generally does not include trabeculae. Hence, inserting catheter assembly  702  through an aortic valve  732  into an upper portion left ventricle  720  allows gutter catheter  704  to be navigated within left ventricle  720  along wall  724  substantially without being obstructed by trabeculae or cordae tendonae. 
     Gutter catheter  704  generally includes an opening or lumen (not shown) that is sized to accommodate a guide wire through which a guide wire may be inserted. The opening may be located along the central axis of gutter catheter  704 , i.e., central axis  730  as shown in  FIG. 7   a . Delivering a guide wire through gutter catheter  704  enables the guide wire to effectively follow the contour of wall  724 . In general, the guide wire may include an anchoring tip which enables the guide wire to be substantially anchored against wall  724 .  FIG. 8  is a diagrammatic top-view cut-away representation of a left side of a heart in which a guide wire has been positioned in accordance with an embodiment of the present invention. It should be appreciated that the representation of the left side of a heart in  FIG. 8  has not been drawn to scale, and that various features have been exaggerated for ease of discussion. A guide wire  802  is positioned along wall  724  of left ventricle  720 . Once guide wire  802  is inserted through gutter catheter  704  of  FIGS. 7   a - 7   c , and anchored against wall  724  using an anchoring tip  806 , gutter catheter  704 , along with J-catheter  708 , are withdrawn from the body of the patient. It should be appreciated that delivery tube  604  typically remains positioned within the aorta after guide wire  802  is anchored to wall  724 . 
     Guide wire  802 , which may be formed from a material such as stainless steel or a shape memory material, is generally anchored such that guide wire  802  effectively passes along a large portion of wall  724 . Typically, guide wire  802  serves as a track over which a catheter that carries plication structures may be positioned, i.e., a lumen of a catheter that delivers a plication element may pass over guide wire  802 . Such a catheter may include a balloon structure (not shown), or an expandable structure, that may facilitate the positioning of local plication structures by pushing the local plication structures substantially against the fibrous tissue around the mitral valve. 
     Forming local plications causes bunches of the fibrous tissue around the mitral valve to be captured or gathered, thereby causing dilation of the mitral valve to be reduced. In general, the local plications are discrete plications formed in the fibrous tissue around the mitral valve using suture structures or discrete mechanical elements.  FIG. 9   a  is a representation of a top-down cut-away view of a left ventricle of the heart in which local plication suture structures have been implanted in accordance with an embodiment of the present invention. Suture structures, which include T-bars  904  and threads  907 , are implanted in tissue near a mitral valve  916 , e.g., an annulus of mitral valve  916 . Typically, the tissue in which suture structures are implanted is fibrous tissue  940  which is located substantially around mitral valve  916 . Suitable suture structures include, but are not limited to, structures which include T-bars  904  and threads  907 , as will be described below with reference to  FIGS. 10   a ,  10   b ,  11 , and  12   a - c.    
     Since T-bars  904  or similar structures, when implanted, may cut through tissue  940 , pledgets  905  may against a ventricular side tissue  940  to effectively “cushion” T-bars  904 . Hence, portions of T-bars  904  are positioned above mitral valve  916 , i.e., on an atrial side of mitral valve  916 , while pledgets  905  are positioned on the ventricular side of mitral valve  916 . It should be appreciated that additional or alternative pledgets may be positioned on the atrial side of mitral valve  916 , substantially between tissue  940  and T-bars  904 . Catheters which deliver suture structures  904  to an atrial side of mitral valve  916  from a ventricular side of mitral valve  916  will be discussed below with respect to  FIGS. 13   a - c.    
     In the described embodiment, T-bars  904  are coupled such that every two T-bars, e.g., T-bars  904   a , is coupled by a thread, e.g., thread  907   a . Thread  907   a  is configured to enable T-bars  904   a  to be tensioned together and locked against tissue  940 . Locking T-bars  904   a  enables tissue  940  to be bunched or slightly gathered, thereby effectively constraining the size, e.g., arc length, of mitral valve  916  by reducing the an arc length associated with tissue  940 . In other words, the presence of T-bars  904  which cooperate with thread  907  to function substantially as sutures, allows the size of a gap  908  between an anterior leaflet  920  and a posterior leaflet  918  to be reduced and, further, to be substantially prevented from increasing. As will be appreciated by those skilled in the art, over time, scar tissue (not shown) may form over pledgets  905  and T-bars  904 . 
     Generally, the number of T-bars  904  used to locally bunch or gather tissue  940  may be widely varied. For instance, when substantially only a small, localized regurgitant jet occurs in mitral valve  916 , only a small number of T-bars  904  may be implemented in proximity to the regurgitant jet. Alternatively, when the size of gap  908  is significant, and there is a relatively large amount of mitral valve leakage, then a relatively large number of T-bars  904  and, hence, pledgets  905  may be used to reduce the size of gap  908  by reducing the arc length of mitral valve  916 . Some pledgets  905  may be arranged to at least partially overlap. To correct for a regurgitant jet that is centralized to only one section of mitral valve  916 , T-bars  904  may be implemented as plicating elements near the regurgitant jet, and as reinforcing elements away from the regurgitant jet, e.g., to prevent progression of mitral valve disease from causing a substantial gap to eventually form. 
     While the coupling of two T-bars  904   a  with thread  907   a  has been described, it should be understood that the number of T-bars  904  coupled by a thread or threads  907  may vary. For example, if multiple T-bars  904  are coupled by multiple threads  907 , then it may be possible to gather more fibrous tissue using fewer total T-bars  904 . With reference to  FIG. 9   b , the use of multiple T-bars  904  which are coupled by multiple threads  907  will be described. T-bars  904   c  are coupled by a thread  907   c , while T-bars  904   d  are coupled by a thread  907   c . Similarly, T-bars  904   e  are coupled by a thread  907   e . T-bar  904   d ′ is further coupled by a thread  907   f  to T-bar  904   c ″, and T-bars  904   d ″ is also coupled by a thread  907   g  to T-bar  904   e ′. As will be discussed below, threads  907  enable T-bars  904  to be pulled against pledgets  905  and, hence, tissue  940 . Such coupling of T-bars  904  enables plications in tissue  940  to be made between T-bars  904   c , between T-bars  904   d , and between T-bars  904   e , while allowing tissue to be at least somewhat gathered between T-bar  904   c ″ and T-bar  904   d ′, and between T-bar  904   d ″ and T-bar  904   e′.    
     In general, the configurations of suture structures which include T-bars  904  and threads  907  may vary. One embodiment of a suitable suture structure is shown in  FIGS. 10   a  and  10   b .  FIGS. 10   a  and  10   b  are representations of a suture structure after T-bars have been introduced to an atrial side of fibrous tissue near a mitral valve in accordance with an embodiment of the present invention. For purposes of illustration, it should be understood that the elements and structures represented in  FIGS. 10   a  and  10   b , as well as substantially all other figures, have not been drawn to scale. A suture structure  1000  includes T-bars  904 , or reinforcing elements, that are coupled to thread  907  such that when thread  907  is pulled, T-bars  904  effectively push against tissue  940 . As shown in  FIG. 10   b , pulling on thread  907  and pushing on a locking element  1002  causes locking element  1002  to contact a ventricular side of tissue  940  and to effectively hold T-bars  904  against tissue  940 . Specifically, pulling on a loop  1004  of thread  907  while pushing on locking element  1002  tightens T-bars  904  against tissue  940  such that a plication  1006  may be formed in tissue  940  when locking element  1002  locks into position to lock T-bars  904  into place. 
     Pledgets  905 , as will be appreciated by those skilled in the art, may serve as plication anchors for T-bars  904  which essentially function as sutures. That is, pledgets  905  may prevent T-bars  904  from cutting through tissue  940 . In general, the configuration of pledgets  905  may vary widely. For example, pledgets  905  may have a substantially tubular form, and may be formed from a material such as surgical, e.g., Dacron, mesh. However, it should be appreciated that pledgets  905  may be formed in substantially any shape and from substantially any material which promotes or supports the growth of scar tissue therethrough. Suitable materials include, but are not limited to silk and substantially any biocompatible porous or fibrous material. 
     Locking element  1002  may be a one-way locking element, e.g., an element which may not be easily unlocked once it is locked, that is formed from a biocompatible polymer. The configuration of a locking element  1002  may be widely varied. Alternative configurations of locking element  1002  will be described below with respect to  FIG. 11  and  FIGS. 12   a - c . In order to engage locking element  1002  against pledgets  905 , a catheter which is used to deliver T-bars  904  may be used to push locking element  1002  into a locked position. A catheter which delivers T-bars  904  and may also be used to engage locking element  1002  will be discussed below with reference to  FIGS. 13   a - c.    
     Like locking element  1002 , T-bars  904  may also be formed from a biocompatible polymer. Thread  907 , which may be coupled to T-bars  904  through tying T-bars  904  to thread  907  or molding T-bars  904  over thread  907 , may be formed from substantially any material which is typically used to form sutures. Suitable materials include, but are not limited to, silk, prolene, braided Dacron, and polytetrafluoroethylene (PTFE, or GoreTex). 
     As mentioned above, the configuration of locking element  1002  may vary. For example, a locking element may include a spring element as shown in  FIG. 11 . A suture structure  1100  include T-bars  1104 , a thread  1107 , and a locking element  1102 . For ease of illustration, the elements of suture structure  1100  have not been drawn to scale. Although suture structure  1100  is not illustrated as including a pledget, it should be appreciated that suture structure  1100  may include a pledget or pledgets which serve as reinforcing elements which generally support the growth of scar tissue. 
     Locking element  1102  includes solid elements  1102   a  and a spring element  1102   b . Although solid elements  1102   a  may be formed from a biocompatible polymer, solid elements  1102   a  may also be formed from material which is typically used to form pledgets. Spring element  1102   b  is arranged to be held in an extended position, as shown, while a loop  1114  in thread  1107  is pulled on. Once T-bars  1104  are in contact with tissue  1140 , solid elements  1102   a  may come into contact with tissue  1140 , and spring element  1102   b  may contract to create a spring force that pulls solid elements  1102   a  toward each other. In other words, once T-bars  1104  are properly positioned against tissue  1140 , locking element  1102  may be locked to form a plication or local bunching of tissue  1140 . 
     In one embodiment, the formation of scar tissue on the fibrous tissue which is in proximity to a mitral valve may be promoted before a plication is formed, or before the fibrous tissue is gathered to compensate for mitral valve insufficiency. With reference to  FIGS. 12   a - c , a locking element which promotes the growth of scar tissue before a plication is formed will be described in accordance with an embodiment of the present invention. As shown in  FIG. 12   a , a suture structure  1200 , which is not drawn to scale, includes a locking element  1204 , a thread  1207 , and T-bars  1204 . Locking element  1204 , which includes solid elements  1202   a , a spring element  1202   b , and a resorbable polymer overmold  1202   c  formed over spring element  1202   b  is coupled to thread  1207  on a ventricular side of tissue  1240 . 
     Overmold  1202   c , which may be formed from a resorbable lactide polymer such as PURASORB, which is available from PURAC America of Lincolnshire, Ill., is formed over spring element  1202   b  while spring element  1202   b  is in an extended position. Overmold  1202   c  is arranged to remain intact while scar tissue  1250  forms over solid elements  1202   a . In one embodiment, in order to facilitate the formation of scar tissue, solid elements  1202   a  may be formed from material that is porous or fibrous, e.g., “pledget material.” 
     Once scar tissue is formed over solid elements  1202   a , overmold  1202   c  breaks down, e.g., degrades, to expose spring element  1202   b , as shown in  FIG. 12   b . As will be understood by one of skill in the art, the chemical composition of overmold  1202   c  may be tuned such that the amount of time that elapses before overmold  1202   c  breaks down may be controlled, e.g., controlled to break down after a desired amount of scar tissue is expected to be formed. Hence, once overmold  1202   c  breaks down, and spring element  1202   b  is allowed to contract, as shown in  FIG. 12   c , enough scar tissue  1250  will generally have formed over solid elements  1202   a  to effectively bond solid elements  1202   a  against tissue  1240  to allow for the formation of a relatively strong plication or gathering of tissue  1240 . 
     While a loop  1214  of thread  1207  may be allowed to remain extended into a left ventricle of a heart, thread  1207  may be cut, i.e., loop  1214  may be effectively removed, to reduce the amount of loose thread  1207  in the heart. Alternatively, loose thread  1207  may effectively be eliminated by gathering thread  1207  around a cylindrical arrangement (not shown) positioned over locking element  1202 . That is, a spool or similar element may be included as a part of suture structure  1200  to enable loose thread  1207  to either be gathered within the spool or gathered around the exterior of the spool. 
     The use of overmold  1202   c  enables anchoring forces which hold T-bars  1204  and locking element  1202  in position to be relatively low, as substantially no significant forces act on tissue  1240  until after scar tissue or tissue ingrowth is created. Once scar tissue is created, and overmold  1202   c  has degraded, then spring  1202   b  compresses. The anchoring forces generated at this time may be relatively high. However, as scar tissue has been created, the likelihood that T-bars  1204  cut into tissue  1240  at this time is generally relatively low. 
     As mentioned above, catheters may be used to deliver suture structures into a heart, and to engage the suture structures to tissue around the mitral valve of the heart. One embodiment of a suture structure delivery catheter which is suitable for use in a catheter-based annuloplasty that uses local plications will be described with respect to  FIG. 13   a . A delivery catheter  1300  may be positioned over a guide wire, e.g., guide wire  802  as shown in  FIG. 8 , which serves as a track to enable delivery catheter  1300  to be delivered in the gutter of a heart. It should be appreciated that the elements of delivery catheter  1302  have not been drawn to scale. Within delivery catheter  1300  is a wire  1308  which carries T-bars  1304  of a suture structure. In one embodiment, T-bars  1300  are coupled to a thread  1307  and a locking element  1300  to form the suture structure. Typically, a pointed or sharpened end  1311  of wire  1308  is configured to penetrate tissue (not shown), e.g., fibrous tissue of the heart near a mitral valve. Once end  1311  and T-bar  1304  are located above fibrous tissue, e.g., on an atrial side of a mitral valve, wire  1308  may be retracted a repositioned. After wire  1308  is repositioned, end  1311  may once again penetrate tissue to effectively deposit T-bar  1304  over tissue on the atrial side of the mitral valve. 
     Wire  1308  or, more specifically, end  1311  may be used to pull thread  1307  and to push locking element  1302  into position against tissue near the mitral valve. By way of example, end  1311  may pull on thread  1307  until T-bars  1304  contact the tissue. Then, end  1311  may be used to lock locking element  1302  against the tissue and, as a result, create a plication in the tissue to effectively shrink the annulus of the mitral valve. 
     In order to create additional plications, wire  1308  and, in one embodiment, delivery catheter  1300 , may be retracted entirely out of a patient to enable additional T-bars to be loaded onto wire  1308 . Once additional T-bars are positioned on wire  1308 , wire  1308  may be reinserted into delivery catheter  1300 , and delivery catheter  1300  may be used to enable another plication to be created in the tissue which is located near the mitral valve. 
       FIG. 13   b  is a representation of a second catheter which is suitable for delivering a suture structure in accordance with an embodiment of the present invention. A catheter  1340 , which is not drawn to scale and which may include a lumen (not shown) that is arranged to be inserted over a guide wire, includes two wires  1348  which are arranged to cooperate to carry a suture structure. As shown, wire  1348   a  carries a T-bar  1344   a  while wire  1348   b  carries a T-bar  1344   b  which are coupled by a thread  1347  and, together with a locking element  1342 , form a suture structure. Tips  1351  of wires  1348  pass through tissue near a mitral valve to deposit T-bars  1344  above the mitral valve. Once T-bars  1344  are deposited, tips  1351  may be used to pull T-bars  1344  against the tissue, as well as to lock locking element  1342  against an opposite side of the tissue. By way of example, tip  1351   b  may be configured to pull on thread  1347  while tip  1351   a  pushes against locking element  1342 . 
     With reference to  FIG. 13   c , a catheter arrangement which may deploy T-bars from its tip will be described in accordance with an embodiment of the present invention. A catheter arrangement  1360  includes two catheters which each carry a T-bar  1364 . It should be appreciated that the elements of  FIG. 13   c  have not been drawn to scale for ease of illustration. Specifically, catheter  1360   a  carries T-bar  1364   a  at its tip, while catheter  1360   b  carries T-bar  1364   b  at its tip. A thread  1367  couples T-bars  1364  together such that a locking element  1362  through which thread  1367  passes may lock T-bars  1364  substantially against tissue of a heart. 
     In one embodiment, catheter arrangement  1360  may require the use of two guide wires to guide each of catheter  1360   a  and catheter  1360   b  into the gutter of the heart. Alternatively, catheter  1360   a  and catheter  1360   b  may be arranged such that both catheter  1360   a  and catheter  1360   b  may be guided through the gutter of the heart through the use of a single guide wire. 
     Catheter  1360   a  is configured to push T-bar  1364   a  through tissue near the mitral valve of the heart, and to release T-bar  1364   a  once T-bar  1364   a  is located on an atrial side of the mitral valve. Similarly, catheter  1360   b  is configured to push T-bar  1364   b  through the tissue, and to release T-bar  1364   b . T-bars  1364  may be released, for example, when heat is applied to a dielectric associated with catheters  1360  that causes T-bars  1364  to be effectively snapped off. Alternatively, a mechanical mechanism (not shown) that engages T-bars  1364  to catheters  1360  may be disengaged to release T-bars  1354 . Once T-bars  1364  are positioned on the atrial side of the mitral valve, catheter  1360  may be used to pull on thread  1367  and to push on locking element  1362 . 
     With reference to  FIGS. 14   a  and  14   b , the performance of an annuloplasty procedure using a catheter-based system which implants suture structures in tissue near a mitral valve will be described in accordance with an embodiment of the present invention. Once a patient is prepared, e.g., sedated, an annuloplasty procedure  1400  may begin with the insertion of a delivery tube and a J-catheter into the left ventricle of the heart of the patient. The delivery tube and the J-catheter may be inserted into the body of the patient through the femoral artery, and threaded through the femoral artery and the aorta into the left ventricle of the heart. Generally, the J-catheter is positioned within the delivery tube. One embodiment of the delivery tube and a J-catheter were described above with respect to  FIGS. 6   a  and  6   b . As will be appreciated by those skilled in the art, the delivery tube and the J-catheter are typically each threaded through the aortic valve to reach the left ventricle. 
     Once the delivery tube and the J-catheter are positioned within the left ventricle, a gutter catheter may be extended through the J-catheter in step  1408 . As was discussed above with reference to  FIGS. 7   a - c , the gutter catheter is arranged to effectively run against a gutter of the wall of the left ventricle substantially immediately under the mitral valve. Specifically, the gutter catheter may be positioned in the space in the left ventricle between the mitral valve and the musculi papillares, or papillary muscles. The gutter catheter often has a tip that is steerable and flexible. In one embodiment, the tip of the gutter catheter may be coupled to an inflatable balloon. The J-catheter serves, among other purposes, the purpose of allowing the gutter catheter to be initially oriented in a proper direction such that the gutter catheter may be positioned along the wall of the left ventricle. 
     In step  1412 , a guide wire with an anchoring feature may be delivered through the gutter catheter, e.g., through a lumen or opening in the gutter catheter. The guide wire is delivered through the gutter catheter such that it follows the contour of the gutter catheter against the wall of the left ventricle. After the guide wire is delivered, the anchoring feature of the guide wire is anchored on the wall of the left ventricle in step  1416 . Anchoring the guide wire, or otherwise implanting the guide wire, on the wall of the left ventricle enables the guide wire to maintain its position within the left ventricle. 
     The J-catheter and the gutter catheter are pulled out of the left ventricle through the femoral artery in step  1420 , leaving the guide wire anchored within the left ventricle, as was discussed above with respect to  FIG. 8 . A T-bar assembly delivery catheter which carries a T-bar assembly is then inserted through the femoral artery into the left ventricle over the guide wire in step  1436 . In one embodiment, the T-bar assembly delivery catheter carries an uninflated balloon. 
     After the T-bar assembly delivery catheter is inserted into the left ventricle, the balloon is inflated in step  1428 . Inflating the balloon, e.g., an elastomeric balloon, at a relatively modest pressure using, for example, an air supply coupled to the balloon through the T-bar assembly delivery catheter, serves to enable substantially any catheter which uses the guide wire as a track to be pressed up against the fibrous tissue around the mitral valve. Generally, the inflated balloon substantially occupies the space between the mitral valve and the papillary muscles. In one embodiment, more than one balloon may be inflated in the left ventricle. 
     Once the balloon is inflated in step  1428 . The T-bar assembly delivery catheter effectively delivers T-bars, or similar mechanisms, pledgets, and thread which are arranged to attach or otherwise couple with an annulus of the mitral valve, e.g., the fibrous tissue of the skeleton around the mitral valve, to create plications. Suitable catheters were described above with respect to  FIGS. 13   a - c . In step  1440 , a plication is created using the T-bar assembly in substantially any suitable tissue near the mitral valve. For example, a plication may be created by essentially forcing T-bars through the tissue, then locking the T-bars against the tissue using a locking mechanism of the T-bar assembly. Specifically, the plication or bunching of tissue may be created by extending sharpened wires which carry elements such as T-bars through the tissue, then retracting the sharpened wires, and pulling the T-bars into place. Positioning the T-bars, and locking the locking mechanism causes the tissue between the T-bars and the locking mechanism may bunch together. 
     Once the plication is created in step  1440 , the balloon is generally deflated in step  1442 . The T-bar assembly delivery catheter may then be removed through the femoral artery in step  1444 . A determination is made in step  1448  after the T-bar assembly delivery catheter is removed as to whether additional plications are to be created. If it is determined that additional plications are to be created, then process flow returns to step  1436  in which the T-bar assembly delivery catheter, which carries a T-bar assembly or suture structure, is reinserted into the femoral artery. 
     Alternatively, if it is determined in step  1448  that there are no more plications to be created, then process flow proceeds to step  1456  in which the guide wire may be removed. After the guide wire is removed, the delivery tube may be removed in step  1460 . Once the delivery tube is removed, the annuloplasty procedure is completed. 
     In lieu of using suture structures such as T-bar assemblies to create local plications, other elements may also be used to create local plications in fibrous tissue near the mitral valve during an annuloplasty procedure.  FIG. 15  is a cut-away top view representation of a left side of a heart in which local plications have been created using individual, discrete elements in accordance with an embodiment of the present invention. Local plication elements  1522  are effectively implanted in fibrous tissue  1540  around portions of a mitral valve  1516  in order to reduce the size of a gap  1508  between an anterior leaflet  1520  and a posterior leaflet  1518 , e.g., to reduce the arc length associated with posterior leaflet  1518 . Local plication elements  1522  are arranged to gather sections of tissue  1540  to create local plications. The local plications created by local plication elements  1522 , which are generally mechanical elements, reduce the size of the mitral valve annulus and, hence, reduce the size of gap  1508 . As will be understood by those skilled in the art, over time, scar tissue may grow around or over local plication elements  1522 . 
     The configuration of local plication elements  1522  may be widely varied. For example, local plication elements  1522  may be metallic elements which have spring-like characteristics, or deformable metallic elements which have shape memory characteristics. Alternatively, each local plication element  1522  may be formed from separate pieces which may be physically locked together to form a plication. With reference to  FIGS. 16   a - d , one embodiment of a local plication element which has spring-like characteristics will be described in accordance with an embodiment of the present invention. A local plication element  1622  may be delivered to a ventricular side, or bottom side, of tissue  1640  which is located near a mitral valve. When delivered, as for example through a catheter, element  1622  is in a substantially folded, closed orientation, as shown in  FIG. 16   a . In other words, element  1622  is in a closed configuration that facilitates the delivery of element  1622  through a catheter. After an initial compressive force is applied at corners  1607  of element  1622 , sides or tines  1609  of element  1622  may unfold or open. As tines  1609  open, tips  1606  of tines  1609  may be pressed against tissue  1640 , as shown in  FIG. 16   b . The application of compressive force to tines  1609 , as well as a pushing force to a bottom  1611  of element  1622 , allows tips  1606  and, hence, tines  1609  to grab tissue  1640  as tips  1606  push through tissue  1640 , as shown in  FIG. 16   c . The closing of tines  1609 , due to compressive forces applied to tines  1609 , causes tissue  1640  to be gathered between tines  1609  and, as a result, causes a plication  1630  to be formed, as shown in  FIG. 16   d . In one embodiment, the catheter (not shown) that delivers element  1622  may be used to apply forces to element  1622 . 
     As mentioned above, elements used to create local plications may be created from shape memory materials. The use of a shape memory material to create a plication element allows the plication element to be self-locking.  FIG. 17   a  is a representation of one plication element which is formed from a shape memory material in accordance with an embodiment of the present invention. A clip  1704 , which may be formed from a shape memory material, i.e., an alloy of nickel and titanium, is arranged to be in an expanded state or open state when it is introduced, e.g., by a catheter, into the gutter of the left ventricle. Typically, holding clip  1704  in an expanded state involves applying force to clip  1704 . In one embodiment, a catheter may hold sides  1708  of clip  1704  to maintain clip  1704  in an expanded state. 
     Once tips  1706  of clip  1704  are pushed through the fibrous tissue near the mitral valve of the heart such that tips  1706  are positioned on an atrial side of the mitral valve, force may be removed from clip  1704 . Since clip  1704  is formed from a shape memory material, once force is removed, clip  1704  forms itself into its “rest” state of shape, as shown in  FIG. 17   b . In its rest state or preferred state, clip  1704  is arranged to gather tissue in an opening  1712  defined by clip  1704 . That is, the default state of clip  1704  is a closed configuration which is effective to bunch tissue to create a local plication. 
     Another discrete self-locking plication element which is suitable for creating a local plication is a clip which may twist from an open position to a closed, or engaged position, once force applied to hold the clip in an open position is removed.  FIG. 18   a  is a representation of another self-locking plication element shown in a closed position in accordance with an embodiment of the present invention. A clip element  1800 , which may be formed from a material such as stainless steel or a shape memory material, is preloaded such that once tissue  1830  is positioned in a gap  1810  between a tine  1806  and a time  1808 , clip element  1800  may return to a state which causes tissue  1830  to be pinched within a gap or space  1810 . 
     Tine  1806  and tine  1808  first pierce tissue  1830 , e.g., the tissue of an annulus of a mitral valve. As tine  1806  and tine  1808  are drawn together to create a plication, thereby reducing the size of gap  1810  by reducing a distance  1820 , a bottom portion  1812  of clip element  1800  twists, as for example in a quarter turn, effectively by virtue of shape memory characteristics of clip element  1800 . Thus, an effective lock that holds tine  1806  and tine  1808  in a closed position such that tissue  1830  is gathered to form a local plication results. 
     In lieu of a preloaded clip element, a clip element may include a lock mechanism which engages when force is applied.  FIG. 18   a  is a representation of a self-locking plication element which includes a sliding lock in accordance with an embodiment of the present invention. A clip element  1850  includes a body  1852  and a slider  1862  which is arranged to slide over at least a portion of body  1852 . Clip element  1850 , which may be formed from a material such as stainless steel or a shape memory alloy, includes a tip  1856  and a tip  1858  which are substantially separated by a gap  1856  when slider  1862  is in an unlocked position. As shown, slider  1862  is in an unlocked or open position when slider  1862  is positioned about a tapered neck  1854  of body  1852 . 
     When clip element  1850  is delivered into a left ventricle, e.g., using a catheter, clip element  1850  is positioned within the left ventricle such that tip  1856  and tip  1858  are effectively pierced through fibrous tissue  1880  near the mitral valve. After tip  1856  and tip  1858  are positioned substantially on an atrial side of tissue  1880 , force may be applied to slider  1862  to move slider  1862  in a y-direction  1870   b  over body  1852 . As slider moves in y-direction  1870   b  away from tapered neck  1854 , slider  1862  forces tip  1856  and tip  1858  together close gap  1860 , i.e., tip  1856  and tip  1858  move towards each other in an x-direction  1870   a . When tip  1856  and tip  1858  cooperate to close gap  1860 , tissue  1880  is gathered within clip element  1850 , thereby creating a local plication. 
     In one embodiment, when slider  1862  is in a closed position such that tip  1856  and tip  1858  cooperate to close gap  1856 , slider  1862  may contact tissue  1880 . Hence, in order to promote the growth of scar tissue over parts of clip element  1850  or, more specifically, slider  1862 , at least a top surface of slider  1862  may be covered with a pledget material, e.g., a mesh which supports the growth of scar tissue therethrough. 
     Locking elements which create local plications may include elements which have two or more substantially separate pieces which lock together around tissue. An example of a locking element which includes two separate pieces is shown in  FIG. 19 . As shown in  FIG. 19 , a locking element  2000  may include a receiver piece  2002  and a locker piece  2004 , which may generally be formed from substantially any suitable material, as for example a biocompatible plastic material. Receiver piece  2002  and locker piece  2004  each include a tine  2006 . Tines  2006  are arranged to pierce and to engage tissue to create a local plication. 
     A cable tie portion  2010  of locker piece  2004  is configured to be drawn through an opening  2008  which engages cable tie portion  2010 . Opening  2008  includes features (not shown) which allow cable tie portion  2010  to be pulled through opening  2008  and locked into position, and which prevent cable tie portion  2010  substantially from being pushed out of opening  2008 . Cable tie portion  2010  is locked in opening  2008  when bevels  2012  come into contact and effectively force tines  2006  to clamp down. Once tines  2006  clamp down, and locker piece  2004  is locked against receiver piece  2002 , a local plication is formed. 
     The operation of locking element  2000  will be described with respect to  FIGS. 20   a - d  in accordance with an embodiment of the present invention. As shown in  FIG. 20   a , receiver piece  2002  and locker piece  2004  may be delivered substantially beneath fibrous tissue  2050  near a mitral valve (not shown). Receiver piece  2002  and locker piece  2004  may be delivered using a catheter which includes a top surface  2054 . Top surface  2054  of the catheter is arranged to apply force to tines  2006  such that tines  2006  remain in an effectively undeployed, e.g., partially bent or folded, position while being delivered by the catheter. 
     Once receiver piece  2002  and locker piece  2004  are positioned under tissue  2050  near a location where a plication is to be formed, forces are applied to receiver piece  2002  and locker piece  2004  to push receiver piece  2002  and locker piece  2004  together and effectively through an opening  2058  in top surface  2054  of the catheter, as shown in  FIG. 20   b . The forces are typically applied by mechanisms (not shown) associated with the catheter. As tines  2006  pass through opening  2058 , tines  2006  “open,” or deploy in order to pierce tissue  2050 . 
     After piercing tissue  2050 , tines  2006  continue to penetrate and to gather tissue  2050  while receiver piece  2002  and locker piece  2004  are pushed together. As receiver piece  2002  and locker piece  2004  are pushed together, cable tie portion  2010  is inserted into opening  2008  (shown in  FIG. 19 ) of receiver portion  2002 , as shown in  FIG. 20   c . Cable tie portion  2010  eventually locks with respect to opening  2008  when bevels  2012  come into contact. When bevels  2012  come into contact, tines  2006  close inwards, causing tissue  2050  to be captured, i.e., causing a local plication  2060  to be formed. Once a local plication is formed, and force is no longer required to push receiver piece  2002  and locker piece  2004  together, the catheter which delivered receiver piece  2002  and locker piece  2004  may be removed from the left ventricle. 
     Referring next to  FIGS. 21   a  and  21   b , an annuloplasty procedure which uses a catheter-based system to create local plications in tissue near a mitral valve using discrete elements will be described in accordance with an embodiment of the present invention. After a patient is prepared, an annuloplasty procedure  2100  may begin with the insertion of a delivery tube and a J-catheter into the left ventricle of the heart of the patient in step  2104 . Once the delivery tube and the J-catheter are positioned within the left ventricle, a gutter catheter may be extended through the J-catheter in step  2108 . The gutter catheter, as described above, is arranged to effectively run against a gutter of the wall of the left ventricle, e.g., between the mitral valve and the papillary muscles. The gutter catheter often has a tip that is steerable and flexible. 
     In step  2112 , a guide wire with an anchoring feature may be delivered through the gutter catheter, e.g., through a lumen or opening in the gutter catheter. The guide wire is delivered through the gutter catheter such that it follows the contour of the gutter catheter against the wall of the left ventricle. After the guide wire is delivered, the anchoring feature of the guide wire is anchored on the wall of the left ventricle in step  2116 . 
     The J-catheter and the gutter catheter are pulled out of the left ventricle through the femoral artery in step  2120 , leaving the guide wire anchored within the left ventricle, as was discussed above with respect to  FIG. 8 . A plication element delivery catheter which carries a plication element and, in one embodiment, is arranged to engage the plication element to the fibrous tissue around the mitral valve is inserted through the femoral artery into the left ventricle over the guide wire in step  2132 . The plication element delivery catheter, in the described embodiment, is coupled to an uninflated balloon which is inflated in step  2134  to effectively allow the plication element delivery catheter to be positioned substantially directly under the fibrous tissue. Once the plication element delivery catheter is positioned in the left ventricle, e.g., over the guide wire in the gutter of the left ventricle, and the balloon is inflated, the plication element delivered by the delivery catheter is engaged to the fibrous tissue in step  2136 . That is, the plication element is coupled to the fibrous tissue such that a local plication is formed in the fibrous tissue. 
     After the local plication is created in step  2136  by engaging tissue using the plication element, the balloon is deflated in step  2138 . Upon deflating the balloon, the plication element delivery catheter may be removed through the femoral artery in step  2140 . A determination is then made in step  2142  as to whether additional local plications are to be created. That is, it is determined if other plication elements are to be introduced into the left ventricle. If it is determined that additional local plications are to be created, process flow returns to step  2132  in which the plication element delivery catheter, which carries another plication element, is reinserted into the femoral artery. 
     Alternatively, if it is determined in step  2142  that there are no more local plications to be created, then the indication is that a sufficient number of local plications have already been created. Accordingly, the guide wire may be removed in step  2148 , and the delivery tube may be removed in step  2152 . After the delivery tube is removed, the annuloplasty procedure is completed. 
     A catheter which may enable an orthogonal access to a mitral valve may enable the catheter to be more accurately positioned underneath the mitral valve. As discussed above, a catheter may become at least partially tangled in trabeculae which are located in the left ventricle of a heart. As such, inserting a catheter which does not extend too deeply into the left ventricle may prevent significant tangling. Any tangling may impede the efficiency with which the catheter may be positioned beneath a mitral valve. One catheter which may be less likely to become at least partially tangled in trabeculae, while also enabling an orthogonal access to a mitral valve, is an L-shaped catheter, which is shown in  FIG. 22   a . An L-shaped catheter arrangement  2200 , which includes a delivery tube  2201  and an L-shaped catheter  2202  which may be formed from a biocompatible material that is typically also relatively flexible, is arranged to allow the tip of L-catheter  2202  to maintain an “L” shape when passed through an aortic valve  2206  into a left ventricle  2204 . After delivery tube  2201  and L-shaped catheter  2202  are effectively “snaked” or inserted through a femoral artery, a tip  2208  of L-shaped catheter may be positioned at a top portion of left ventricle  2204 , where there is typically a minimal amount of trabeculae. 
     Tip  2208  of L-shaped catheter  2202  may be extended in a straight orientation such that tip  2208  effectively forms an “L” with respect to delivery tube  2201  and the remainder of L-shaped catheter  2202 . In one embodiment, as tip  2208  is extended under a mitral valve  2212 , a string  2210  or another part, e.g., a wire, that may be coupled to tip  2208  may extend through an opening in delivery tube  2201  as shown in  FIG. 22   b . String  2210  may effectively allow tip  2208  to be bent or otherwise moved around underneath to position tip  2208  into contact with mitral valve  2212 , as shown in  FIG. 22   c.    
     The use of string  2210  to pull on tip  2208  allows, in cooperation with extending L-shaped catheter  2202 , tip  2208  to be moved beneath mitral valve  2212  into desired positions. Hence, desired locations beneath mitral valve  2212  may relatively easily be reached to enable plications (not shown) to be created in the desired locations. In the described embodiment, string  2210  may enable a curve to be created in L-shaped catheter  2202  that is substantially an approximately ninety degree curve. 
     L-shaped catheter  2202  may be used to create plications in mitral valve  2212  using a variety of different methods. Specifically, tip  2208  of L-shaped catheter  2202  may be temporarily fixed in a position beneath mitral valve  2212 , e.g., in a gutter of the heart, during a process of creating a plication in mitral valve  2212 . In one embodiment, suction may be used to gather a portion of tissue near mitral valve  2212  either such that a plication may be made in the portion, or such that a temporary anchor point may be created. Suction generally enables tissue to be substantially gathered such that an apparatus, as for example a clip or a similar apparatus, may be put into place to hold the gathered tissue. Alternatively, suction may be used to secure or firmly anchor tip  2208  against mitral valve  2212  such that an anchor for a plication may be deployed with improved accuracy. When tip  2208  is anchored into tissue near mitral valve  2212 , an anchor for a plication or a temporary anchor may be more precisely placed, as the position of tip  2208  is effectively fixed. 
       FIGS. 23   a  and  23   b  are diagrammatic representations of orientations of a tip area of an L-shaped catheter which may be used with suction to anchor the tip area to a mitral valve in accordance with an embodiment of the present invention. As shown in  FIG. 23   a , a tip  2308  of a catheter such as an L-shaped catheter, e.g., L-shaped catheter  2202  of  FIG. 22   c , may include an opening  2314  on a side of tip  2308 . Opening  2314  may be positioned under tissue  2312  such that when suction is applied through opening  2314 , tip  2308  is effectively temporarily fixed against tissue  2312 . Alternatively, as shown in  FIG. 23   b , a tip  2318  of an L-shaped catheter may include an end opening  2324 , i.e., an opening at an endpoint of tip  2318 , that allows opening  2324  to contact tissue  2322  such that when suction is applied through opening  2324 , tip  2312  is held relatively firmly against tissue  2322 . Temporarily anchoring a catheter near a mitral valve generally allows plication elements to be more accurately deployed using the catheter. 
     In lieu of using suction to anchor the tip area of a catheter to tissue near a mitral valve, a wire with a coil which may be extended through a catheter such that the wire may be temporarily anchored into tissue near the mitral valve such that other catheters may track over the wire. For example, a wire with a helical coil or a spiral at the tip may be engaged against tissue by applying force to the tip of the wire, turning the wire such that the helical coil portion of the wire turns through the tissue, the pushing the coil through the tissue.  FIGS. 24   a  and  24   b  are diagrammatic representations of a wire with a helical coil which may be suitable for use in as a temporary anchor that is anchored into tissue near a mitral valve in accordance with an embodiment of the present invention. A wire  2430  with a coiled tip  2432 , as shown in  FIG. 24   a , may be extended through a catheter (not shown) while a tip of the catheter may, in one embodiment, effectively be anchored against tissue near a mitral valve. Wire  2430  may be inserted in a catheter (not shown) such that a longitudinal axis of wire  2430  is parallel to a longitudinal axis of a tip (not shown) of the catheter. As shown in  FIG. 24   b , coiled tip  2432  may extend through a lumen of a tip  2440  of an L-shaped catheter to enable tip  2440  to be substantially anchored when coiled tip  2432  is anchored against tissue. Coiled tip  2432  is incorporated in the tip of the catheter, and would be engaged by rotating the entire catheter. This design features a working lumen that is coaxial with the center of the helical tip to enable a T-bar that is pushed down the lumen to pass through the center of the helix as the T-bar is effectively forced through tissue. It should be appreciated that, in one embodiment, a coiled tip may be included as a part of an L-shaped catheter, i.e., the catheter may include a coiled tip. 
     A wire  2430  with a coiled tip  2432  may generally be used as a temporary anchor which may remain coupled to tissue even after a catheter through which wire  2430  was deployed is retracted. That is, wire  2430  may serve as a track over which other catheters may be “run” to enable a particular position, i.e., a position identified by the location of coiled tip  2432  with respect to the tissue, to be repeatedly accessed or located by catheters. 
     In general, temporary fixation is a relatively reversible process. By effectively temporarily fixing or anchoring a catheter or a coiled tip of a wire against mitral valve tissue or tissue near a mitral valve, it is relatively easy to position, release, and re-position the wire and, hence, a catheter that tracks over the wire substantially without trauma, and substantially without causing an irreversible action to occur. A temporary anchor may provide a tension or counter-traction force for the application of a permanent anchor. That is, counter-traction on the temporary anchor may be used to provide a tissue penetration force for the permanent anchor. Possible permanent anchors generally include both single anchor points, e.g., applying one T-bar with a second T-bar being needed to for a plications, and dual anchor points, e.g., applying a clip or a staple which creates a plication between its points. 
     Once a catheter is effectively anchored into position, as for example over a wire such as wire  2430 , then anchors which are used to create plications may be deployed. Typically, two anchor points are used to form a single plication.  FIG. 25  is a diagrammatic representation of an anchor which is deployed and anchored into tissue in accordance with an embodiment of the present invention. An anchor  2504 , which is coupled to a tether or a tail  2500 , is deployed through tissue  2508  such that anchor  2504  is pushed through tissue  2508  while tail  2500  is allowed to extend, e.g., to an exterior of the body of a patient. In one embodiment, anchor  2504  may be a temporary anchor which is not actually used in the creation of a plication but is, instead, used to allow anchors used for plications to be positioned. In such an embodiment, anchor  2504  may be used to enable a first permanent anchor to be anchored. Alternatively, anchor  2504  may be an anchor, e.g., a T-bar, which is intended to be used to create a plication. For ease of discussion, anchor  2504  is described as being a first permanent anchor that was previously anchored into position by guiding a catheter over a temporary anchor (not shown). 
     An incrementor catheter may use tail  2500  as a guide over which the incrementor catheter may be positioned. An incrementor catheter, as shown in  FIG. 26   a , may generally include two sections. A first section  2602  of an incrementor catheter  2600 , may be inserted over tail  2500 . In one embodiment, first section  2602  may be used to insert anchor  2504 , e.g., when incrementor catheter  2600  is configured as an L-shaped catheter. 
     Once first section  2602  is positioned over tail  2500  such that first section  2602  is in relatively close proximity to tissue  2508 , a second section  2604  may be extended away from first section  2602 , as for example by a nominal separation or distance ‘d,’ as shown in  FIG. 26   b . The positioning of first section  2602  over tail  2500  enables first section  2602  to be temporarily fixed. With first section  2602  being temporarily fixed, second section  2604  may be controlled such that a tip of second section  2604  may be rotated, extended, or retraced to control the penetration angle of an anchor (not shown) that is to be deployed. 
     Additionally, when first section  2602  is temporarily fixed, the position of first section  2602  may be maintained for enough time to perform substantially all desired tests and to withstand forces associated with the desired test. Further, substantially all forces associated with the manipulation of incrementor catheter  2602 . 
     Distance ‘d’ may be substantially any distance, and is typically selected to be a distance which allows a plication created using anchor  2504  and an anchor (not shown) that is to be deployed through second section  2604  to be effectively created. When second section  2604  is used to deploy either a temporary or permanent anchor (not shown), second section  2604  is effectively a working lumen of incrementor catheter  2600 . 
     The location of anchors may generally be verified using a number of technologies which include, but are not limited to, ultrasound techniques, fluoroscopy techniques, and electrical signals. With some of the technologies, the injection of marking agents, e.g., contrast agents for fluoroscopy or microspheres for ultrasound, may increase contrast and promote visibility. Typically, such injections may be into a ventricular space, within mitral valve tissue, or in through the mitral valve tissue into atrial space. It should be appreciated that the verification of locations may further enable a distance ‘d’ between consecutive anchors to be more accurately maintained. 
       FIG. 27  is a diagrammatic representation of two anchors which may be used to create a plication in accordance with an embodiment of the present invention. Anchor  2504  and an anchor  2704 , which may be deployed using second section  2604  of incrementor catheter  2600  of  FIG. 26   b , are separated by distance ‘d.’ Each anchor  2504 ,  2704  has a tail section, i.e., tail  2500  and a tail  2700 , respectively, which, after incrementor catheter  2600  of  FIG. 26   b  is withdrawn from underneath tissue  2508 , may be pulled on or tensioned such that a plication is effectively created between anchor  2504  and anchor  2704 . Once a plication is created, tails  2500 ,  2700  may be trimmed. 
     In general, a daisy chain of plications may be created using an incrementor catheter. That is, the incrementor catheter may be used to anchor a series of anchors which are each substantially separated by a distance ‘d.’ Once a daisy chain of anchors is in place in mitral valve tissue, pairs of the anchors may effectively be tied off to create a series or a daisy chain of plications. With reference to  FIG. 28   a - f , a process of creating a daisy chain of plications will be described in accordance with an embodiment of the present invention. As shown in  FIG. 28   a , a first anchor  2802   a , which may be a T-bar, has a tail  2806   a  such as a suture and is anchored to tissue  2804 . Typically, tissue  2804  is tissue of a mitral valve annulus, or tissue near a mitral valve. A second anchor  2802   b , which has a tail  2806   b  is also anchored into tissue  2804 . Typically, the distance between second anchor  2802   b  and first anchor  2802   a  is a measured distance, i.e., the distance between second anchor  2802   b  and first anchor  2802   a  is predetermined. In one embodiment, the distance is substantially controlled using an incrementor catheter. 
     Once first anchor  2802   a  and second anchor  2802   b  are in place, a locker  2810   a  is delivered over tails  2806   a ,  2806   b , as shown in  FIG. 28   b . Once locker  2810   a  is delivered, tail  2806   a  may be tensioned, substantially locked, and trimmed. Tensioning of tail  2806   b , as shown in  FIG. 28   c , allows a first plication  2820  to be effectively created. Tail  2806   b  remains untrimmed, as second anchor  2802   b  is arranged to be included in a second plication of a daisy chain of plications. That is, second anchor  2802   b  may effectively be shared by more than one plication. A third anchor  2802   c  which has a tail  2806   c , as shown in  FIG. 28   d , is anchored into tissue  2804  at a specified distance from second anchor  2802   b , e.g., through the use of an incrementor catheter. 
     A locker  2810   b  may be delivered over tail  2806   b  and tail  2806   c , and tail  2806   b  may be tensioned, locked, and trimmed as shown in  FIG. 28   e . When tail  2806   c  is tensioned, a second plication  2830  is created, as shown in  FIG. 28   f . It should be appreciated that if tail  2806  is also locked and trimmed, then a daisy chain of two plications  2820 ,  2830  is completed. Alternatively, if more plications are to be added, then additional anchors and lockers may be positioned as appropriate such that tail  2806   c  serves as a “starting point” for the additional plications. 
     Instead of using an L-shaped catheter to create anchor points, substantially any other suitable catheter may be used to access tissue near a mitral valve or a mitral valve annulus, e.g., to achieve a substantially orthogonal access to mitral valve tissue. In one embodiment, a suitable catheter may be a hook catheter which effectively includes an approximately 180 degree curve may be used to create anchor points and plications.  FIG. 29   a  is a diagrammatic representation of a hook catheter in accordance with an embodiment of the present invention. A hook catheter  2900 , which includes a tip  2902  that is effectively a terminus of a curved portion  2903  of hook catheter  2900 , is inserted through an aortic valve  2904  into a left ventricle  2906 . 
     Once hook catheter  2900  is positioned or, more specifically, once tip  2902  is positioned near mitral valve tissue  2908 , a string  2910  which may be coupled to tip  2902  as shown in  FIG. 29   b , may be pulled on or tensioned and slackened, as appropriate, to enable tip  2902  to be positioned in a desired location with respect to mitral valve tissue  2908 . As will be appreciated by those skilled in the art, string  2910  is often a wire such as a pull wire or a deflection wire that is axially translatable. By allowing string  2910  to enable tip  902  to be positioned in a desired location, hook catheter  2900  may effectively be considered to be a deflectable or steerable tip catheter. A temporary anchor, e.g., a helical coil such as helical coil  2432  of  FIG. 24   a , may be anchored to mitral valve tissue  2908  by deploying the temporary anchor through hook catheter  2900 .  FIG. 29   c  is a diagrammatic representation of a temporary anchor that is positioned within a heart in accordance with an embodiment of the present invention. An anchoring coil  2920 , which is coupled to a wire  2922 , may be anchored to mitral valve tissue  2908  such that wire  2922  may serve as a guide over which a catheter, as for example either a catheter such as a hook catheter which delivers a permanent anchor or an incrementor catheter, which may also deliver a permanent anchor, may be positioned. 
     In lieu of using hook catheter  2900  to deploy a temporary anchor, catheter  2900  may instead be used to deploy a more permanent anchor such as a T-bar. As shown in  FIG. 29   d , a T-bar  2940  may be pushed through mitral valve tissue  2908  using tip  2902  of hook catheter  2900 . When hook catheter  2900  is withdrawn from left ventricle  2906 , T-bar  2940  effectively remains anchored in mitral valve tissue  2908 , while a tail  2942  of T-bar  2940  may extend to an exterior of the body of a patient, as shown in  FIG. 29   e.    
     After T-bar  2940  or, more generally, an anchor is in position, then an incrementor catheter may be snaked or otherwise passed over tail  2942 .  FIG. 29   f  is a diagrammatic representation of an incrementor catheter that is positioned over tail  2942  in accordance with an embodiment of the present invention. An incrementor catheter  2950  is positioned such that a first section  2952  of incrementor catheter  2950  may be guided by tail  2942  until a tip of first section  2952  is substantially directly under T-bar  2940 . Then, a second section  2954  of incrementor catheter  2950  may be extended until a tip of second section  2954  is positioned approximately a distance ‘d’ away from T-bar  2940 . A second T-bar (not shown) or anchor may then be deployed using second section  2954 . Once a second T-bar is deployed, incrementor catheter  2950  may be removed from left ventricle  2906 . 
     The use of an incrementor catheter  2950  allows two T-bars, e.g., T-bar  2940  and T-bar  2980  of  FIG. 29   g , to be anchored to mitral valve tissue  2908  such that T-bars  2940 ,  2980  may be spaced apart at approximately a distance ‘d,’ while tails  2942 ,  2982 , respectively, may extend outside of a body of a patient. In other words, incrementor catheter  2950  generally enables the distance between adjacent T-bars to be more carefully controlled. 
     In order to create a plication using T-bars  2940 ,  2980 , a locking bar  2990 , as shown in  FIG. 29   h , may be provided over tails  2942 ,  2982  such that mitral valve tissue  2908  may effectively be pinched between T-bars  2940 ,  2980  and locking bar  2990 . Once a plication is created, tails  2942 ,  2982  may be trimmed or otherwise cut. 
     With reference to  FIG. 30 , the steps associated with one method of creating a plication using an access catheter which has a 180 degree retrograde active-curve tip, e.g., a hook catheter, an incrementor catheter, and a helical coil for creating a temporary anchor will be described in accordance with an embodiment of the present invention. A process  3000  begins at step  3020  in which a catheter, e.g., a hook catheter, is inserted in a substantially straight configuration through an introducer into a femoral artery of a patient. Once the catheter is inserted, the tip of the catheter is prolapsed into a hook shape in step  3040 . A gap between an end of the hook portion and the main portion of the catheter may be reduced to a dimension that is small enough to prevent tangling of the tip in chords or leaflets of the heart. Prolapsing of the tip may generally occur within the aorta of a heart, at a femoral artery bifurcation, or within the left ventricle of the heart. It should be appreciated that when the tip of the catheter is deflectable, the tip of the catheter may be deflected or substantially actively changed into a hook shape within the aorta of the heart, or within the left ventricle of the heart. 
     In step  3060 , the tip of the catheter may be positioned within the left ventricle. By way of example, the catheter tip may be positioned at a level that is just inferior to the level of the mitral valve annulus, and the catheter segment that includes the hook shape may be rotated such that it lies against either the anterior or posterior aspect of the aortic outflow tract, depending upon which aspect is to be treated. In one embodiment, the distal catheter segment is aligned such that when extended, the tip of the catheter may point towards one of the entrances to the gutter of the heart. The entrances to the gutter of the heart may include substantially any relatively clear entrance to the gutter with respect to the leaflets of the heart, as for example a medial P 1  location, a mid P 2  location, or a lateral P 3  location. 
     After the tip of the catheter is positioned, the tip of the catheter may be hooked into the gutter in step  3080 . Hooking the catheter tip into the gutter may include repeatedly extending the retrograde tip to increase the gap between the tip and the proximal segment of the catheter, retracting the entire catheter and sensing engagement of the tip with the gutter, and, if necessary, one again positioning the tip of the catheter in the left ventricle before rehooking the tip. 
     Once the catheter tip is hooked into the gutter, the location of the tip is confirmed in step  3100 . Confirming the location of the tip may include, but is not limited to, as previously mentioned, sensing electrical signals of the heart, fluoroscopy with or without the injection of contrast, and ultrasound with or without the injection of microspheres. When the tip location is confirmed, a temporary anchor may be attached in step  3120 . The temporary anchor may be a helical coil, e.g., helical coil  2432  of  FIG. 24   a , that is attached by applying a longitudinal pressure and torque. Typically, when the helical coil is attached, a lumen or a tail of the helical coil remains connected to the helical coil. 
     In the described embodiment, after the temporary anchor is attached, the location of the temporary anchor is confirmed in step  3140 . Methods used to confirm the location of the temporary anchor may be the same as methods used to confirm the location of a catheter tip, and may also include injecting contrast or microspheres into tissue or through tissue to the atrial space above a mitral valve. 
     A permanent anchor is attached in step  3160  using the connection to the temporary anchor as a guide. The permanent anchor may be attached to the same location, and may provide a counter-traction force for tissue engagement. Like the temporary anchor, the permanent anchor generally includes a tail. 
     Once a permanent anchor is in place, an incrementor catheter is delivered into the heart in step  3180 . In general, the incrementor catheter is delivered in a closed configuration to the location of the first anchor, e.g., the permanent anchor attached in step  3160 , by tracking a first section of the incrementor catheter over the tail of the first anchor. After the incrementor catheter is delivered, the incrementor catheter may be deployed in step  3200  to create a nominal distance or gap between the first anchor location and the working lumen, e.g., a second section, of the incrementor catheter. Then, in step  3220 , a second permanent anchor may be applied at the nominal distance from the first permanent anchor. It should be appreciated that temporary anchors may be used to facilitate the positioning of the second permanent anchor. Applying the second permanent anchor typically includes retracting the incrementor catheter once the second permanent anchor is anchored into a desired location. 
     After both the first permanent anchor and the second permanent anchor are applied, a locker is delivered into the heart in step  3240 . Delivering the locker generally includes tracking the locker or locking device over the two tails of the first and the second permanent anchors. The locker may be fixed into position by applying tension to the locker to create a plication substantially between the two permanent anchors. 
     Once the locker has been tensioned, the tails of the anchors may be severed, and the process of creating a plication is completed. It should be appreciated that, in one embodiment, steps  3180  to  3260  may generally be repeated to create a daisy chain of interlocking plications. 
     Although only a few embodiments of the present invention have been described, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or the scope of the present invention. By way of example, methods of introducing plication elements or suture structures into the left ventricle to correct for mitral valve leakage, or mitral valve insufficiency, may be applied to introducing plication elements or suture structures which correct for leakage in other valves. For instance, the above-described procedure may be adapted for use in repair a leaking valve associated with a right ventricle. 
     While creating local plications in fibrous tissue associated with the mitral valve of the heart has generally been described, the plications may also be created in other types of tissue which are near, around, in proximity to, or include the mitral valve. As will be appreciated by those skilled in the art, other tissues to which plications may be formed that are near, around, in proximity to, or include the mitral valve include tissues associated with the coronary sinus, tissues associated with the myocardium, or tissues associated with the wall of the left ventricle. In one embodiment, a plication may be substantially directly formed in the leaflets of the mitral valve. 
     It should be understood that although a guide wire has been described as including an anchoring tip to anchor the guide wire to a wall of the left ventricle, a guide wire may be anchored with respect to the left ventricle in substantially any suitable manner. By way of example, a guide wire may include an anchoring feature which is located away from the tip of the guide wire. In addition, a guide wire may more generally be any suitable guiding element which is configured to facilitate the positioning of an implant. 
     While access to the gutter of the left ventricle has been described as being associated with a minimally invasive catheter annuloplasty procedure in which local plications are formed, it should be understood that the gutter of the left ventricle may also be accessed, e.g., for an annuloplasty procedure, as a part of a surgical procedure in which local plications are formed. For instance, the aorta of a heart may be accessed through an open chest surgical procedure before a catheter is inserted into the aorta to reach the left ventricle. Alternatively, suture structures or plications elements may be introduced on a ventricular side of a mitral valve through a ventricular wall which is accessed during an open chest surgical procedure. 
     Pledgets have been described as being used in conjunction with, or as a part of, suture structures to facilitate the growth of scar tissue as a result of an annuloplasty procedure. It should be appreciated, however, that the use of pledgets is optional. In addition, although pledgets have generally not been described as being used with clip elements which create local plications, it should be understood that pledgets may also be implemented with respect to clip elements. By way of example, a clip element which includes tines may be configured such that the tines pierce through pledgets before engaging tissue without departing from the spirit or the scope of the present invention. 
     When a clip element has tines that are arranged to pierce through a pledget before engaging tissue, the pledget may be of a hollow, substantially cylindrical shape that enables the pledget be delivered to a left ventricle over a guide wire positioned in the gutter of the left ventricle. The clip element may then be delivered by a catheter through the pledget. A substantially cylindrically shaped, hollow pledget which is to be used with a suture structure may also be delivered over a guide wire, and the suture structure may then be delivered through the pledget. Delivering the suture structure through the pledget may enable a loop of thread that remains after the suture structure is locked into place to remain substantially within the pledget. 
     The configuration of clip elements may generally vary widely. Specifically, the shape of clip elements, the size of clip elements, and the materials from which the clip elements are formed may be widely varied. For instance, in addition to clip elements that are formed from shape memory material, preloaded, or self-locking using mechanical structures, clip elements may also be formed from thermally expandable materials. That is, a clip may be formed such that it is in an open or flat position when delivered into a left ventricle. Such a clip may have an outer or “bottom” element that has a relatively high coefficient of thermal expansion, and an inner or “top” element that deforms under the load generated by the outer element when heat is applied to cause the outer element to bend. Such a clip, once bent or deformed through the application of heat, may pierce tissue. When more heat is applied, the clip may bend more such that tissue is engaged between ends or sides of the clip to create a local plication. In such a system, the inner material may be arranged to maintain its deformed shape once heat is no longer applied, and the heat may be applied through a catheter. 
     Suture structures and plication elements have been described as being used to correct for mitral valve insufficiency. In general, suture structures and plication elements may also be used to essentially prevent the onset of mitral valve insufficiency. That is, local plications may be created to effectively stem the progression of mitral valve insuffiency be reinforcing the perimeter of the annulus around the mitral valve. 
     While suture structures that include T-bars, thread, and locking elements, and are delivered to a left ventricle using a catheter, may be used to form discrete plications in fibrous tissue around the mitral valve, it should be appreciated that sutures may also be sewn into the fibrous tissue. For example, a catheter which is inserted into the left ventricle through the aorta may be configured to sew sutures into the fibrous tissue using mechanisms carried by the catheter. Such sutures that are sewn into the fibrous tissue may be sewn in any conventional orientation, e.g., in an arc along the perimeter of the posterior leaflet of the mitral valve. 
     Suture structures that include T-bars have generally been described as including two T-bars which are located at ends of a thread, with a locking element and pledgets located therebetween, as shown, for example, in  FIG. 10   a . The configuration of suture structures, however, may vary widely. By way of example, a suture structure with two T-bars may include one T-bar at one end of the thread and a second T-bar which is located along the length of the thread such that pulling on a loose end of the thread pulls the two T-bars together. Alternatively, a suture structure may include more than two T-bars. 
     In general, the use of a single element type to create local plications during an annuloplasty procedure has been described. It should be understood that in one embodiment, different element types may be used in a single annuloplasty procedure. For instance, both clip elements and suture elements may be used to create plications during a single annuloplasty procedure. Alternatively, different types of clip elements or different types of suture elements may be used during a particular annuloplasty procedure. 
     The steps associated with performing a catheter-based annuloplasty may be widely varied. Steps may generally be added, removed, reordered, and altered without departing from the spirit or the scope of the present invention. Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.