Patent Publication Number: US-10772678-B2

Title: Methods and devices for diastolic assist

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a non-provisional of U.S. Provisional Application 61/911,456 filed on Dec. 3, 2013; the entirety of which is incorporated by reference and U.S. Provisional Application 61/884,332 filed on Sep. 30, 2013. 
     BACKGROUND OF THE INVENTION 
     Congestive heart failure (CHF) in the United States has a prevalence of approximately 5.8 million people and an incidence of approximately 550,000 people annually. CHF is a rapidly growing medical problem. CHF can be categorized as either systolic heart failure (SHF) or diastolic heart failure (DHF). The estimated direct and indirect cost of CHF in the United States for 2009 is $37.2 billion. CHF is the primary reason for 12-15 million office visits and 6.5 million hospital days each year. CHF is also thought to be the cause of at least 20 percent of all hospital admissions among patients older than 65. Over the past decade, the rate of hospitalizations for heart failure has increased by 159 percent. About half of all patients with CHF have DHF. DHF has an annual mortality of −10%. 
     The hearts of patients with diastolic dysfunction can contract normally or even with hyperdynamic function. However, in patients experiencing DHF, the part of the cardiac cycle that involves diastole is abnormal as the left ventricle cannot relax or expand sufficiently. The inability of the left ventricle to fully relax results in sub-optimal filling of the left ventricle with blood. 
     In particular, diastolic dysfunction is determined by two factors: 1) active myocardial relaxation, primarily affecting early diastole; or 2) passive elasticity or distensibility of the left ventricle, primarily affecting late diastole. 
     The abnormal filling of the ventricles in DHF results in limited cardiac output, especially during exertion. As a result, for any given ventricular volume in a heart with DHF, ventricular pressures are elevated, with backup in the circulatory system, leading to pulmonary congestion and edema identical to those seen in patients with SHF. Symptomatically, patients may immediately feel short of breath. This dysfunction can ultimately lead to multiorgan dysfunction and death. 
     There are currently no approved devices for diastolic dysfunction. Additionally, pharmaceutical intervention has not yet shown to improve outcomes in this population. 
     BRIEF SUMMARY OF THE INVENTION 
     The present disclosure includes devices and methods to increase volume in these hyperdynamic hearts to allow improved physiology and ventricular filling and to reduce diastolic filling pressure. For example, the treatments described herein, when performed in a diseased heart, can result in the heart chamber filling to an increased volume of blood (as compared to pre-treatment volumes) at the same pressure. Thereby, the chamber can move more volume than it could pre-treatment. 
     In a first variation, the disclosure includes a method of improving a diastolic heart function in a heart of a patient having diastolic heart dysfunction. One variation of the method includes positioning a medical device within a body of the patient; advancing the medical device into an interior chamber of the heart; creating at least one incision in cardiac muscle forming an interior heart wall of the interior chamber without cutting through the exterior part of said heart wall, where the incision is sufficient to reduce a stiffness of the interior chamber to increase volume of the chamber and reduce diastolic filing pressure. 
     The above method can further include creating a plurality of incision. The plurality of incision can comprise at least one hole in the cardiac muscle or can comprise creating a plurality of incision. 
     Typically the method includes creating at least one incision without reducing the integrity of the cardiac muscle. 
     Access to the heart can occur via a vascular approach, an open surgical approach, or a thoracoscopic approach. Furthermore, advancing the medical device can comprise advancing the medical device into the interior chamber of the heart via a transapical approach. 
     The devices used to create the therapeutic injury can include any devices selected from the group consisting of a blade, a mechanical cutting device, an electrosurgical device, and a laser device. 
     In some variations, the methods occur by inducing tachycardia of the heart. Furthermore, incisions can be created on an interior of the heart. 
     The devices can be secured to cardiac muscle prior to or during creating the incision. 
     The methods and devices can also optionally deliver bioactive agent to at least one incision to modify the healing process of the cardiac muscle. 
     Another variation of the method includes a method of increasing blood flow in a diseased heart. One such example includes positioning a medical device within a body of the patient; advancing the medical device into an interior chamber of the heart; locating a target area of heart tissue; and creating at least one incision in cardiac muscle of the heart tissue to decrease the stiffness of the interior chamber to permit the interior chamber to increase in volume during diastole. One variation of the device used to make the one or more incisions mentioned above includes a soft semicircular tip at the distal end of the device that may be in fluid communication with an injection port outside the patient. The tip can be imaged when inside the heart under xray fluoroscopic imaging or any other type of imaging or virtual tracking. When the tip is placed into the area of the apex of the heart, the tip configuration changes and the change can be seen during imaging. A contrast imaging agent may be injected through the tip when injected outside the patient through the injection port. Said contrast agent flows into the ventricle. The pattern of flow gives information to the user as to where the cutting member is relative to the inside wall of the ventricle. When the cutting member is adjacent to or embedded in the muscle of the heart wall, the contrast agent will flow only to the surface of the inside wall while the cutting element will be seen within that wall. The contrast agent can also be seen within the cut made in the heart wall. 
     Another variation of the methods includes methods of increasing blood flow in a diseased heart by advancing a device within a left ventricle of the heart; placing an elastic member within the left ventricle such that upon diastole the elastic member expands with the left ventricle. The elastic member has one or more arms. At least one of these arms may have a cutting member. The cutting member may be moved along the inside of the ventricle wall making a controlled incision therein. The depth of the incision is controlled by the distance between the arm and/or elastic member and the tip of the cutting member. If several cutting members are included, these members may be moved individually or together by a cable or other coupled member connecting the cutting member to an actuator outside of the patient to increase a volume within the left ventricle so as to increase blood flow therein. 
     The elastic member can comprise a plurality of elastic members positioned in a substantially concentric pattern within the left ventricle. Alternatively, or in combination, the elastic member can comprise at least one spirally shaped elastic member positioned in a substantially concentric pattern within the left ventricle. 
     The present disclosure also includes variations of medical devices for creating the elongated incisions within soft tissue. In one example the device comprises a handle comprising a handle body and an actuating member; a flexible shaft having a near end coupled to the handle body and a far end, the flexible shaft; an atraumatic tip located at the far end; a cutting member pivotally secured within the flexible shaft and having a cutting edge; and a linking member coupling the actuating member of the handle to the cutting member, wherein when the actuating member applies a tensile force to the linking member, the cutting member pivots to a lateral side of the flexible shaft to expose the cutting surface and allow cutting of the soft tissue, the tensile force also causing biasing of the far end of flexible shaft towards the lateral side to assist in maintaining the cutting surface within the soft tissue. 
     A variation of the device includes a channel extending between the near end of the flexible shaft through the opening. In addition, the medical device can further include a sheath being slidably located on the flexible shaft, where the sheath can be advanced to cover the opening and retracted to expose the opening. 
     Variations of the medical device can include a cutting member that comprises an electrically non-conductive material. In such cases, the cutting member can optionally include at least one electrode located on the electrically non-conductive material, where the at least one electrode is electrically coupleable to a source of electrical current. 
     In alternate variations, the cutting member comprises an electrically conductive material and where the cutting member is electrically coupleable to a source of electrical current. 
     The devices described herein can have one or more openings adjacent to the far end of the flexible shaft, where the cutting surface of the cutting member extends through the opening when pivoted. In some variations, the device further comprises one or more electrodes adjacent to the opening. 
     The devices described herein can further include a rigid section at the far end of the flexible shaft where the rigid section comprises an opening through which the cutting surface of the cutting member extends when pivoted. As discussed herein, the rigid section at the far end of the device provides uniformity to create the incision, while the flexible nature of the shaft permits navigation to remote tissues through tortuous anatomy. 
     The devices described herein can include an atraumatic tip located at the far end of the flexible shaft. The atraumatic tip can comprise a curved elastic member or any shape that provides a lateral force to assist the cutting member to penetrate tissue. Alternatively, the atraumatic tip can simply comprise a blunt elastic or inelastic material. Variations of the devices can include atraumatic tips that are radiopaque. 
     Furthermore, the devices described herein can employ any additional number of lumens for fluid delivery, guidewire advancement, imaging, etc. 
     This application is related to U.S. Publication No. 201210296153 U.S. patent application Ser. No. 13/277,158 filed on Oct. 19, 2011 and U.S. Provisional Application Nos. 61/394,759 filed on Oct. 19, 2010; 61/478,495 filed on Apr. 23, 2011; 61/504,641 filed on Jul. 5, 2011; 61/884,332 filed on Sep. 30, 2013; and 61/911,456 filed on Dec. 12, 2013, the contents of which are each incorporated herein by reference in its entirety. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIGS. 1A and 1B , illustrate respective top and side views of a first example of a treatment device that can be used to make incisions in soft tissue according to the present disclosure. 
         FIG. 2A  illustrates perspective partial cross sectional view of a far end of the device of  FIGS. 1A and 1B . 
         FIG. 2B  illustrates a partial side view of the device above showing the link being secured between the actuating member and cutting member. 
         FIG. 2C  illustrates a proximal or tensile force applied to the link causing the cutting member to pivot out of the opening towards a lateral side of the device. 
         FIG. 3A  illustrates a variation of the device where a rigid section of the flexible shaft comprises an enclosure that is secured to a distal end of the flexible shaft. 
         FIG. 3B  shows a variation where the flexible shaft houses the cutting member with a reinforcement member (either external or internal to the shaft) coupled to the flexible shaft where the reinforcement member renders the area as a rigid section. 
         FIGS. 4A to 4C  illustrate advancement of a device into a heart to create a lesion as described herein. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The illustrations described herein are examples of the invention. Because of the scope of the invention, it is specifically contemplated that combinations of aspects of specific embodiments or combinations of the specific embodiments themselves are within the scope of this disclosure. 
     As noted above, the methods described herein increase a volume of a chamber of a heart to improve blood flow in diastolic heart failure. For example, incisions, cuts, holes, or other separation of tissue can be made in muscle forming the wall of the left ventricle to improve a diastolic function of the heart. Although the description and claims described herein discuss primarily treatments occurring in a left ventricle, unless specifically discussed or claimed, the treatments can occur in any chamber of the heart (e.g., the atriums and/or ventricles). Typically, access to the chambers of the heart (endocardium) can be made percutaneously or via a transapical approach. Once in the ventricle, small cuts, holes, or a combination thereof are made to the cardiac muscle at one or more layers of the musculature. 
     One of the goals of the therapeutic damage is to increase volume in these hyperdynamic hearts to allow improved physiology and ventricular filling and to reduce diastolic filling pressure by making the ventricle less stiff. In some cases, the type of therapeutic damage, e.g., angles, dimensions, length, depth, density, and architecture shall balance of the integrity of the musculature versus the functional result. Meaning the amount of therapeutic damage to the tissue must be balanced against compromising the integrity of the tissue. In many cases, the treatment can be optimized to ensure adequate function physiologically, hemodynamically, and electrophysiologically. Unless otherwise specified, the therapeutic treatments only extend into one or more layers of the cardiac muscle and not through the wall of the heart. 
     The therapeutic damage caused to the cardiac muscle can be additionally treated with agents that prevent closure of the wounds. Such agents can include pyrolitic carbon, titanium-nitride-oxide, taxanes, fibrinogen, collagen, thrombin, phosphorylcholine, heparin, rapamycin, radioactive 188Re and 32P, silver nitrate, dactinomycin, sirolimus, everolimus, Abt-578, tacrolimus, camptothecin, etoposide, vincristine, mitomycin, fluorouracil, or cell adhesion peptides. Taxanes include, for example, paclitaxel, 10-deacetyltaxol, 7-epi-10-deacetyltaxol, 7-xylosyl-10-deacetyltaxol, 7-epi-taxol, cephalomannine, baccatin III, baccatin V, 10-deacetylbaccatin III, 7-epi-10-deacetylbaccatin III, docetaxel. Other agents that could effect improved function include bioactive substances including proteins and cells like stem cells. 
       FIGS. 1A and 1B , illustrate respective top and side views of a first example of a treatment device  100  that can be used to make incisions in soft tissue according to the present disclosure. As shown, the device includes a handle  102  comprising a handle body  104  and an actuating member  106 . Variations of the device can include handles of any number of configurations. Typically, such variations include an actuating member that is moveable relative to a handle body. Such examples can include triggers, levers, dials, etc. Furthermore, the actuating portion can include a switch type mechanism in the event the respective variation is driven by a motor or other automated means. 
     The device  100  further includes a flexible shaft  110  that extends between a near end  112  and a far end  114 . In the illustrated example, the near end  112  depicted as having an optional stress relief sleeve as well as a fluid port  116  for administering fluid through the device  100 . The devices can also include an optional source of current for coupling to electrodes on the device  100  (as described below), for pacing the soft tissue, monitoring EKG, determining whether the device&#39;s cutting member is embedded within tissue, electrocautery, coagulation and/or electrodeposition of medicines or other substances. Similarly, the device  100  can include one or more sources of fluid  134  for coupling to the device  100  via a fluid port  116 . The fluid can be dispensed through the cutting member opening  124  or through a separate opening. 
     Variation of the device  100  can also include an atraumatic tip  120  that can optionally selected to be radiopaque. Alternatively, or in combination cutting element can be radio-dense so it is visible and its position can be determined during use. The example depicted in  FIGS. 1A and 1B  includes an atraumatic tip having the shape of a curved elastic member. In those cases where the device  100  is used in the heart or other cavity the atraumatic curved member  120  protects the tissue from being punctured by the tip of the device  120 . The elastic curved member  120  also is able to flex and relax when pushed into the apex of the heart or cavity. In those variations where the flexed tip  120  is radiopaque, a physician performing the procedure will be able to observe the shape change of the tip under fluoroscopic imaging. When physician then actuates the device to cut tissue, the elastic property of the tip  120  pushes far end  114  of the device against tissue and assists in keeping the cutting element or member within the soft tissue while the cut is being made. Such a feature is especially useful when cutting heart tissue and the heart muscle is contracted during systole. Optionally, the device  120  can augment the process by pacing of tissue using electrical impulses. 
       FIG. 2A  illustrates perspective partial cross sectional view of a far end  114  of the device  100  of  FIGS. 1A and 1B . In this example, the far end  114  of the flexible shaft includes a relatively rigid section  122  coupled to the shaft  110 . The rigid section  122  carries a cutting member  140  that is secured to the rigid section  122  using a pivot member  144 . The cutting member  140  depicted is for illustration purposes only. Any number of blade shapes can be employed in addition or in combination with the illustrated cutting member. The cutting member  140  is also coupled to a link member  148  at a connection point  150 . The link member  148  extends through the shaft  110  and is secured to the actuating member  106  discussed above. The link  148 , a wire in the illustrated example, can include additional components to assist in applying a tensile force to the cutting member  140 . In the illustrated example, the link member  148  includes an inner tube  152  and an outer tube  154  that are located within a passage  118  of the flexible shaft  110 . Such components can improve the structural integrity of the link  148  or can serve to insulate and/or separate the link  148  from electrical components (not illustrated) extending through the passage  118 . The passage can also include a valve either in the shaft and/or in the handle continuous to prevent back bleeding into the catheter. A channel for a guide wire can also be used. 
       FIG. 2B  illustrates a partial side view of the device  100  discussed above, as shown the link  148  is secured to the actuating member  106  (shown in  FIGS. 1A and 1B ) such that upon application of a tensile force, the link member  148  causes movement of the cutting member  140 . However, prior to actuation, the cutting member  140  is retained within the device  100  so that the cutting surface  14  is shielded and cannot inadvertently cut tissue. Variations of the device can also include additional features  160  can be coupled to the cutting member  140  and/or the link  148  such as a strain gauge, spring, or similar structures that allow either retention of the cutting member within the device  100  or monitoring of the cutting member  140  as it cuts tissue. As illustrated, a variation of the device  100  includes a cutting member  140  having a link connection point  150  that is offset from an axis A-A of an area of the device  100  immediately surrounding the cutting member. This eccentric configuration improves actuation of the cutting member and can cause the far end of the device  100  to preferentially apply a force toward a lateral side of the device where the cutting edge  142  is eventually exposed. Such a feature can increase the ability and ease of which the physician can push the cutting edge  142  into the heart muscle. In additional variations, the entire cutting assembly  140  (including the pivot point  144 ) is offset from the axis towards the lateral side of the device  100 . 
       FIG. 2B  also illustrates an optional sheath  164  or cover that can be slidably mounted on the flexible shaft  110 . During advancement or positioning of the device, the sheath  164  can be advanced over the opening  124  to prevent the cutting member  140  from inadvertently damaging tissue. Moreover, the sheath  164  can function as an added safety measure since distal movement (in the direction of arrows  166  can separate the cutting member from tissue or can push the cutting member back into the device  100  if the link  148  fails. 
       FIG. 2C  illustrates a proximal or tensile force  162  applied to the link  148  causing the cutting member  140  to pivot out of the opening  124  towards a lateral side of the device  100 . In the illustrated variation, the cutting edge  142  is exposed in a rearward direction so that pulling on the device  100  allows the cutting member  140  to cut tissue when the cutting member is advanced adjacent to or positioned within tissue. As noted above, the main passage  118  of the device (or any additional lumen or fluid supply tube) can be used to deliver any number of fluids or substances to an opening in the device, including but not limited to the cutting member opening  124 . 
     In alternate variations, the cutting member  140  includes cutting edges  142  on the front side or on both sides of the cutting member  140  to allow rearward and forward cutting.  FIG. 2C  also illustrates the link  148  being eccentric in relation to an axis of the device. This feature results in a lateral force component as noted by arrows  168 . The lateral force component  168  is directed towards the lateral side of the device and assists in maintaining the cutting member  140  within tissue during cutting. As noted above the lateral force causes the catheter to differentially bend or urges the far end of the device  100  toward the blade side (lateral side), increasing the ability to push the blade into the heart muscle or other soft tissue. Additional variations of the device do not rely upon eccentric placement of the cutting member or link but create a lateral force through adjustment of the blade configuration. In addition, variations of the device include a pivot  144  that is located distally to the link attachment point  146  when the cutting member  140  is exposed. As shown in  FIG. 2C , the link attachment point  146  is proximally located relative to the pivot  144 . This configuration prevents interference between the link  148  and the pivot  144  of the cutting member  140  and allows the link to apply lateral force to the far end of the device so that the device flexes in the direction of the cutting member  140 . 
     As noted above, a variation of the device  100  can include the cutting member  140  that is positioned within a rigid section  122  that is adjacent to the flexible shaft  110 . The rigid section prevents deflection of the area adjacent to the cutting member opening  124 , which allows for greater control of the amount of exposure of the cutting edge. 
       FIG. 3A  illustrates a variation of the device where the rigid section  122  comprises an enclosure that is secured to a distal end of the flexible shaft  110 . The enclosure  122  can comprise a conductive material so that it can be used to apply energy, pace tissue, or sense for contact with tissue. In such a case, the enclosure can be electrically coupled to a power supply  130  via known means  136 . Alternatively, the enclosure can comprise an insulated or non-conductive structure but still selected to maintain rigidity as described above. 
     Alternatively, or in combination, the cutting member  140  can be selected from a conductive material and electrically coupled to a power supply  138  via known means. In additional variations, the cutting member  140  can be fabricated from a non-conducting material or insulative material (e.g., ceramic, polymer, a composite material). In the latter case, the cutting member  140  can optionally include one or more electrodes or energy transfer surfaces that are affixed or positioned on one or both sides of the cutting member  140 . 
     In an additional variation, as shown in  FIG. 3B , the flexible shaft  110  can house the cutting member  140 . In such a case, a reinforcement member  168  (either external or internal to the shaft  110 ) can be coupled to the flexible shaft  110  where the reinforcement member renders the area as a rigid section. 
       FIG. 3B  also illustrates a variation of the device where the flexible shaft  110  includes one or more electrodes  170 ,  172  on an exterior of the shaft  110  and adjacent to the opening  124 . As shown, the electrodes can be coupled to a power supply using known means. The electrode configuration can be employed on the enclosure shown in  FIG. 3A  as well. 
       FIG. 4A  illustrates an example of a treatment device as described herein being used in a chamber of the heart  9 . Clearly, the device  100  can be used in any pocket or cavity of soft tissue. As illustrated, a physician advances a treatment device  100  into a chamber  8  of the heart  9 . Once inside the chamber  8 , in this example the left ventricle, the physician can advance an atraumatic tip  120  of the device  100  against tissue (in this case the apex of the chamber) to provide an opposing force to allow penetration of the cutting member into cardiac tissue. Because the atraumatic tip  120  is elastic and resilient there is a reduced risk that the tip  120  will create undesired injury. In addition, the flexible shaft of the device  100  can include any number of reinforcing member  126  such as braids, coils, polymer coextrusion, etc., that maintains torqueability and/or column strength of the flexible member. Such characteristics are required for accurate placement of the cutting element against the desired area of tissue. As noted above, electrodes (or components of the device) can be used with a power supply  130  to assist in placement of the device, and/or provide therapeutic treatment. In some variations the device can be configured as a bi-polar device, with electrodes of opposite polarity on the device. Alternatively, the device can function in a monopolar or unipolar configuration. In such a case an external electrode  131  can be positioned on a remote area of the patient&#39;s body. 
       FIG. 4B  shows a magnified view of the device  100  being advanced into position at the apex of the heart where deformation of the atraumatic tip  120  applies a force in a lateral direction  168 . As noted above, the atraumatic tip  120  is not limited to a curved configuration; instead, any shape that delivers a biasing force can be employed. Furthermore, some variations of the device may not require a biasing force applied by the tip. 
       FIG. 4B  also illustrates advancement of the cutting member  140  to the lateral side. As noted above, this action can also apply a lateral force to assist in placement of the cutting element  140  within tissue. As shown in  FIG. 4C , The lateral force can assist retention of the cutting element  140  as it is withdrawn in a proximal or rearward direction leaving the therapeutic cut  4  in tissue. As noted above, a strain gauge or other structure can be used to measure the drag or resistance on the device to assist in determining whether the cutting element is engaged in tissue. In any case, as noted above, tension applied by the link not only actuates the cutting member, but also, when positioned in an eccentric location within the shaft, the tension also causes the catheter to differentially bend toward the blade side, increasing the ability to push the blade into the heart muscle. 
     Again, the shape of the blade or cutting member can be selected so that it stays in tissue while being pulled. In certain variations, the cutting member opens from distal to proximal direction so that it can be safely closed by retracting into the device sheath or by pushing a sheath over the cutting member. 
     The cutting element can be an electrically insulated blade (e.g., made of ceramic, polymers, or a composite structure) that allows electrodes on both sides of blade to be electrically isolated from each other. Electrodes can be used to monitor EKG for a current of injury to demonstrate cutting, can be used to pace the heart, demonstrating that the blade is within the heart muscle, and for other uses (electrocautery, depth measurement, electrodeposition of drugs/chemicals). If the cutting element is fabricated from a conductive material, it can be used for pacing, which allows a cut to be made during systole and pushes muscle onto blade for cutting. Alternatively, or in combination, the rigid section of the device can be used as a return electrode for sensing, treatment or manipulation of tissue as discussed above. 
     As noted above, the depth of cut can be varied by making the blade longer or shorter using the adjustments and stops discussed above. It can also be varied in a given-length blade catheter by exposing more or less blade with the angle of exposure varying from barely out of the catheter to 90 degrees from the long axis of the catheter. 
     The handle shown in  FIGS. 1A and 1B  can be ergonomic and allow the cutting element to be exposed by flexing the fingers of the operator&#39;s hand, and retracted by extending the fingers. The stop, as discussed above, can be placed on the handle so that the maximum blade exposure can be limited to a preset angle, corresponding to a preset depth. Electrical components can be connected at the handle which is electrically connected to the blade through the pull wire. 
     In many variations, the tip or cutting edge of the cutting member is sharp enough to allow the heart muscle (or other soft tissue) to be stabbed and the angle between the dull and sharpened side is acute enough to allow cutting with minimal force. An alternative sickle-shape is also possible, which causes the blade to remain within the tissue while being pulled but requires the knife to be pushed backward after the cut to disengage the tissue. 
     The device can also employ a pull-apart or splittable cover that retains the curved atraumatic tip temporarily straight to allow for easy entry into a guiding sheath during use. When this pull-apart cover is pulled off, the curled tip bends once it is unconstrained by the guiding sheath. This makes for ease of use, but also ensures single-use. 
     The diameter of the catheter does not constrain the length of blade or depth of cut as the width of the blade can be reduced to fit within even a small catheter. The length of the blade can therefore be several times the diameter of the catheter. For example, in one example the diameter of the device was 7 French, allowing it to go through the smallest of guide catheters known. 
     The methods described herein can be performed using a number of additional modes to determine proper placement. For example, the methods can be performed under fluoroscopy and/or with contrast agents. Alternatively, or in combination, a device can include a pressure sensing tip or along catheter at one or multiple points that determine when the device is positioned against the heart wall. In another variation, the device can include an opening at the distal end that is attached to arterial sensing equipment. Next, the waveform of a pressure wave is observed. When the hole is covered by tissue, the tissue blunts the waveform. This effect can be used as a test for catheter wall apposition. A physician can also confirm placement using an echocardiogram (TTE, TEE, intracardiac) where image shows position of device relative to wall/tissue. 
     Current can also be used to determine blade contact with tissue. For example, a current can be placed through the tissue (through ekg or similar type electrochemical sensing). As the blade touches the tissue, a voltage change can be measured from the circuit completed by the blade&#39;s contact with tissue. 
     Additionally, implantable hardware within, near, or around these cuts/holes with drug eluting capability may be part of this procedure. As well, the hardware (knife or otherwise) used to make the intervention on the cardiac chambers may be coated with drugs much like in drug coated balloon angioplasty. 
     As noted herein, the physician can create one or more therapeutic incisions, cuts, cores, holes, or other similar therapeutic damage to increase volume in the ventricle when in diastole. As noted above, this damage reduces the stiffness of the ventricle (or cardiac muscle in the wall) to improve ventricular filling and reduce diastolic filling pressure (which resists blood flow into the ventricle). The method includes making one or more therapeutic damage sites within one or more chambers of the heart. In this variation, the treatments occur in the endocardium  2 . Any of the treatment devices  3  described herein can include spring biasing, steering, a steerable sheath or catheter, a pull wire, or other mechanism to assist in navigation or apposition of the working end  4  of the device  3  against the target site. 
     Devices for use in the methods described herein can incorporate alternative design options to improve safety to critical structures and to ensure cuts are made as expected (any combination or singular use of the below may be incorporated with any of the variations of the methods or devices discussed herein.) 
     The devices described herein can be used in other applications as well. For example, devices have application to make MAZE incisions by making multiple cuts in or around the pulmonary vein/s to interrupt conduction of atrial electrical activity. The devices and procedures can be used for commisurotomy, by cutting valve in various places including commissures to decrease valvular stenosis. The devices can be used for any and all cardiovascular structures that have undergone stenosis/sclerosis, such as renal arteries/pulmonary veins after RF exposure by cutting longitudinally with knife catheter. Furthermore, the devices can be used to perform plastys in all chambers of the heart by cutting longitudinally with the knife blade. Another potential use includes septal ablations by cutting longitudinally with the knife device; endarterectomy using the blade as cutting device to remove plaque. This peeling/cutting device will be proximal to a distal umbrella unit at the tip of the device that is used to both peel plaque and prevent embolization. Current open methods of carotid endarterectomy lead to stenosis secondary to opening the vessel and subsequently closing the incision; our method would provide an advantage over this as we would not be opening the vessel. Glaucomaplasty via Canal of Schlem incision thus increasing the diameter of the canal, increasing the flow of aqueous humor, and thus decreasing intraocular pressures. The devices can be used for tear duct plasty as well as looking for chronic sinusitis; third ventriculoplasty for obstructive hydrocephalus; and psialalitluasis intervention to remove stones.