Implantable device for penetrating and delivering agents to cardiac tissue

Abstract

An implantable devices for the effective elimination of an arrhythmogenic site from the myocardium is presented. By inserting small biocompatible conductors and/or insulators into the heart tissue at the arrhythmogenic site, it is possible to effectively eliminate a portion of the tissue from the electric field and current paths within the heart. The device would act as an alternative to the standard techniques for the removal of tissue from the effective contribution to the hearts electrical action which require the destruction of tissue via energy transfer (RF, microwave, cryogenic, etc.). This device is a significant improvement in the state of the art in that it does not require tissue necrosis.In one preferred embodiment the device is a non conductive helix that is permanently implanted into the heart wall around the arrhythmogenic site. In variations on the embodiment, the structure is wholly or partially conductive, the structure is used as an implantable substrate for anti arrhythmic, inflammatory, or angiogenic pharmacological agents, and the structure is deliverable by a catheter with a disengaging stylet. In other preferred embodiments that may incorporate the same variations, the device is a straight or curved stake, or a group of such stakes that are inserted simultaneously.

I claim:  
     
       1. A medical device implantable in a heart, for treating arrhythmogenic sites in the heart, the device comprising: 
       a electrically inactive structure having an exposed surface and biocompatible at least over the exposed surface, said structure adapted to be chronically implanted into cardiac tissue within a region substantially adjacent to an arrhythmogenic site in a heart, and, when so implanted, altering conduction properties of the cardiac tissue within said region; and  
       wherein the structure incorporates a coupling means for releasably coupling the structure to a delivery device operable to deliver the structure to the region and implant the structure into the cardiac tissue, said coupling means operable to enable disengagement and removal of the delivery device after the structure is implanted.  
     
     
       2. The device of claim  1  wherein: 
       said structure is selected from a group consisting of helical bodies, stakes, and cages.  
     
     
       3. The device of claim  1  wherein: 
       said structure is formed of biocompatible materials selected from the group consisting of polytetrafluoroethylene, expanded polytetrafluoroethylene, polyester, polyurethane, silicon, platinum, iridium, titanium, and MP35N.  
     
     
       4. The device of claim  1  wherein: 
       said structure, at least over an outermost portion thereof that includes said exposed surface, is constructed of a biocompatible material selected from the group consisting of platinum black, titanium nitride, sintered platinum, roughened platinum, roughened MP35N, and roughened titanium, whereby the effective surface area of the structure is enhanced to augment electrical coupling of the structure and the cardiac tissue.  
     
     
       5. The device of claim  1  further including: 
       a delivery catheter releasably coupled at a distal end thereof to said structure by said coupling means, adapted for intravascularly delivering the structure into the heart and to said region, and further operable at a proximal end thereof to at least partially embed the structure within said cardiac tissue at said region.  
     
     
       6. The device of claim  1  wherein: 
       said structure includes means for delivering a predetermined pharmacological agent to said cardiac tissue at said region, for further altering conduction properties of said tissue within said region.  
     
     
       7. The device of claim  6  wherein: 
       said structure includes a substrate coated with a non-conductive controlled release matrix less rigid than the substrate, with the controlled release matrix being at least partially embedded within said tissue when the structure is so implanted.  
     
     
       8. The device of claim  6  wherein: 
       said predetermined pharmacological agent is selected from a group consisting of anti-arrhythmic agents, angiogenic growth factors, anti-inflammatory agents, and their combinations.  
     
     
       9. The device of claim  6  wherein: 
       said structure includes a rigid core material forming a proximal head and a distal tip, and an insulative controlled release matrix covering the rigid core material between the head and the tip, to facilitate use of the structure for electrical mapping of said tissue when the structure is at least partially embedded into the tissue.  
     
     
       10. The device of claim  1  wherein: 
       said structure includes a hollow core and a plurality of apertures from the hollow core open to the outer surface of the structure, a proximally located head in fluid communication with the hollow core, and a tube coupled to the head for supplying a pharmacological agent to the hollow core via the head.  
     
     
       11. The device of claim  10  wherein: 
       said structure further includes a non-conductive controlled release matrix forming a coating over said apertures, for delivering said predetermined pharmacological agent to an innermost surface of said controlled release matrix.  
     
     
       12. A method of locally altering electrical activity in cardiac tissue at a selected site in the region of the heart, including: 
       measuring electrical activity in cardiac tissue, to identify a potential implantation site;  
       introducing a first electrically inactive and biocompatible implantable device into the region of the heart, and at least partially embedding said first implantable device into cardiac tissue at the site to effect an implantation.  
     
     
       13. The method of claim  12  further including: 
       after said implantation, performing a plurality of electrical measurements in cardiac tissue proximate the site and, based on results of said electrical measurements, performing at least one of the following sub-steps:  
       (i) determining that the implantation has successfully altered conduction properties as intended;  
       (ii) based on a determination that the implantation has not successfully altered conduction properties as intended, removing and repositioning the first implantable device; and  
       (iii) responsive to determining that the implantation has not successfully altered conduction properties as intended, embedding a second electrically inactive and biocompatible implantable device proximate the first implantable device and proximate said site.  
     
     
       14. The method of claim  13  further including: 
       after said performing the plurality of electrical measurements and before performing said at least one substep, supplying a pharmacological agent via the first implantable device to cardiac tissue Proximate the first implantable device.  
     
     
       15. The method of claim  13  further including: 
       after said implantation and before said performing the plurality of electrical measurements, supplying a pharmacological agent via the first implantable device to cardiac tissue proximate the first implantable device.  
     
     
       16. The method of claim  12  further including: 
       after said implantation of the first implantable device, supplying a pharmacological agent via the first implantable device to cardiac tissue proximate the first implantable device.  
     
     
       17. The method of claim  16  wherein: 
       said supplying of a pharmacological agent comprises delivering the pharmacological agent from a source to the implantable device via a tube coupled to the implantable device.  
     
     
       18. The method of claim  12  wherein: 
       said introducing the first implantable device comprises releasably attaching the first implantable device to a distal end of a catheter, using the catheter to intravascularly deliver the device to the implantation site, manipulating the catheter at a proximal end thereof to achieve said implantation, decoupling the catheter from the first implantable device and withdrawing the catheter after said implantation.  
     
     
       19. An apparatus for locally modifying electrical action within a heart, comprising: 
       an implantable electrically inactive device including tissue penetration means and a coupling means; and  
       a delivery device having a proximal end and a distal end adapted for forming a releasable coupling to said implantable device via the coupling means, adapted for delivering the implantable device to a designated site in a heart and manipulable at said proximal end to implant the implantable device by causing said tissue penetration means to enter tissue; and further adapted for a decoupling from the implantable device and removal after the implantation, whereby the implantable device remains at the site and modifies electrical action at and proximate the site.  
     
     
       20. The apparatus of claim  19  wherein: 
       said implantable device comprises a means to deliver pharmacological agents to cardiac tissue at and proximate the site.  
     
     
       21. An apparatus for locally modifying electrical action within a heart comprising: 
       a biocompatible electrically inactive, implantable device including a means for penetrating cardiac tissue to effect an implantation of the implantable device at a designated site in a heart, to modify electrical action in the cardiac tissue at and proximate the site;  
       
         wherein the implantable device at least over an outermost portion thereof that includes an exposed surface, is constructed of a biocompatible material selected from the group consisting of platinum black, titanium nitride sintered platinum, roughened platinum, roughened MP 35 N and roughened titanium, to enhance the effective surface area of the exposed surface and thereby augment electrical coupling of the implantable device and the cardiac tissue. 
       
     
     
       22. The apparatus of claim  21  wherein: 
       the implantable device includes a non-conductive controlled release matrix for supplying a predetermined pharmacological agent to the cardiac tissue.  
     
     
       23. The apparatus of claim  21  wherein: 
       the implantable device, at least over an outermost portion thereof that includes an exposed surface, is constructed of a biocompatible material selected from the group consisting of platinum black, titanium nitride, sintered platinum, roughened platinum, roughened MP35N and roughened titanium, to enhance the effective surface area of the exposed surface and thereby augment electrical coupling of the implantable device and the cardiac tissue.  
     
     
       24. The apparatus of claim  21  further including: 
       a drug delivery catheter coupled to the implantable device for delivering a pharmacological agent to the implantable device, and wherein the implantable device includes a hollow core in fluid communication with the drug delivery catheter and open to an exterior of the implantable device to supply the pharmacological agent from the delivery catheter to the cardiac tissue.  
     
     
       25. The apparatus of claim  21  further including: 
       a delivery catheter including a catheter distal end region coupled to the implantable device, said delivery catheter operable at a proximal end thereof to effect said implantation; and  
       an electrode means at the catheter distal end for sensing electrical action in the cardiac tissue before said implantation, to facilitate locating the site.  
     
     
       26. The apparatus of claim  25  wherein: 
       the catheter is releasably coupled to the implantable device to allow a decoupling and withdrawal of the delivery catheter after said implantation.  
     
     
       27. An apparatus for supplying a pharmacological agent locally to a depth within cardiac tissue including: 
       
         a biocompatible electrically inactive structure including a permanently implantable tissue penetrating element located distally of the structure and adapted for a penetration of cardiac tissue to a depth within surrounding cardiac tissue, and a proximal portion of the structure adapted to remain exposed outside of the cardiac tissue when the penetrating element is surrounded by the cardiac tissue, and wherein the structure, at least at said penetrating element, is adapted to deliver a pharmacological agent to the surrounding cardiac tissue. 
       
     
     
       28. The apparatus of claim  27  further including: 
         a non - conductive controlled release matrix disposed along the penetrating element for supplying the pharmacological agent to the surrounding cardiac tissue.   
     
     
       29. The apparatus of claim  27  further including: 
       
         a fluid passage through the biocompatible structure, open to an exterior of the structure at said proximal portion and at said penetrating element. 
       
     
     
       30. The apparatus of claim  29  further including: 
       
         a drug delivery catheter coupled to the biocompatible structure and incorporating a lumen fluid coupled to the fluid passage at said proximal portion, to enable supplying of the pharmacological agent from the lumen to the surrounding cardiac tissue via the fluid passage.  
       
     
     
       31. The apparatus of claim  30  further including: 
       
         a delivery device having a distal end region coupled to the biocompatible structure, and operable at a proximal end thereof to effect said penetration. 
       
     
     
       32. The apparatus of claim  31  wherein: 
       
         the delivery device is releasably coupled to the biocompatible device to allow a decoupling and withdrawal of the delivery device after said penetration. 
       
     
     
       33. The apparatus of claim  27  wherein: 
       
         said penetrating element further is adapted to fixate the biocompatible structure by virtue of said penetration. 
       
     
     
       34. The apparatus of claim  27  wherein: 
       
         said penetrating element is selected from a group consisting of helical bodies, stakes, and cages. 
       
     
     
       35. The apparatus of claim  29  wherein: 
       
         the fluid passage is open to the biocompatible structure exterior through an aperture at a distal tip of the penetrating element. 
       
     
     
       36. The apparatus of claim  29  wherein: 
       
         said fluid passage is open to the biocompatible structure exterior through a plurality of apertures disposed along the penetrating element. 
       
     
     
       37. The apparatus of claim  30  wherein: 
       
         said lumen extends to a proximal end of the drug delivery catheter, and is adapted for fluid coupling to a drug delivery port. 
       
     
     
       38. The apparatus of claim  27  wherein: 
         said pharmacological agent is selected from a group consisting of: antiarrhythmic agents, angiogenic growth factors, anti - inflammatory agents, and their combinations.   
     
     
       39. The apparatus of claim  27  further including: 
       
         a delivery catheter having a distal end portion for supporting the biocompatible structure, for guiding the biocompatible structure intervascularly to an interior of the heart, to facilitate said penetration of cardiac tissue from within the heart. 
       
     
     
       40. A process for delivering pharmacological agents at a depth within cardiac tissue at a selected site in a heart, including: 
       
         delivering a biocompatible structure to a heart, and causing an electrically inactive and permanently implantable tissue penetrating element of the structure to penetrate cardiac tissue at a selected site in the heart;  
       
       
         providing a pharmacological agent to the penetrating element, and  
       
       
         after causing the penetration of the penetrating element, delivering the pharmacological agent from a controlled release matrix disposed along the penetrating element to the surrounding tissue. 
       
     
     
       41. The process of claim  40  wherein: 
       
         providing the pharmacological agent to the penetrating element comprises providing the pharmacological agent to a proximal portion of the structure through a lumen of a drug delivery catheter coupled to the biocompatible structure. 
       
     
     
       42. The process of claim  40  wherein: 
       
         said penetrating element is coated with a controlled release matrix, and said providing of the pharmacological agent to the penetrating element comprises providing the pharmacological agent to the controlled release matrix. 
       
     
     
       43. The process of claim  40  wherein: 
       
         said causing the penetrating element to penetrate cardiac tissue comprises causing the penetrating element to penetrate endocardial tissue. 
       
     
     
       44. The process of claim  40  further including: 
         after causing the penetration of the penetrating element further delivering an anti - inflammatory agent from the penetrating element to the surrounding tissue.   
     
     
       45. The process of claim  40  further including: 
       
         after causing the penetration of the penetrating element, delivering an antiarrhythmic agent from the penetrating element to the surrounding tissue. 
       
     
     
       46. The process of claim  40  further including: 
       
         electrically mapping a region of the heart to identify an arrhythmogenic site, wherein said selected site substantially coincides with the arrhythmogenic site. 
       
     
     
       47. The process of claim  46  wherein: 
       
         said mapping is performed before causing the tissue penetrating element of the structure to penetrate the cardiac tissue at the selected site. 
       
     
     
       48. The process of claim  46  wherein: 
       
         said mapping is performed after causing the tissue penetrating element to penetrate cardiac tissue, and includes using the penetrating element as a mapping electrode. 
       
     
     
       49. The process of claim  40  wherein: 
       
         said causing the penetrating element to penetrate cardiac tissue comprises causing the penetrating element to enter the cardiac tissue from within the heart. 
       
     
     
       50. A process for delivering an angiogenic growth factor to a heart, including: 
       
         penetrating a delivery device into heart tissue at a selected site within the heart; and  
       
       
         with the delivery device so penetrated, delivering an angiogenic growth factor to the tissue through the delivery device. 
       
     
     
       51. An apparatus for delivering an angiogenic agent to a heart, including: 
       
         a catheter body having a proximal end, a distal end and a lumen between the proximal and distal ends;  
       
       
         an angiogenic agent in the lumen; and  
       
       
         a tissue penetrating structure disposed at the distal end of the catheter body and adapted to deliver the angiogenic agent from the lumen into heart tissue. 
       
     
     
       52. The apparatus of claim  51  wherein: 
       
         the tissue penetrating structure includes penetrating element, and is adapted to deliver the angiogenic agent through the tissue penetrating element into the heart tissue. 
       
     
     
       53. A process for treating the heart of a patient, including: 
       
         providing a catheter and a penetrating element disposed at a distal end of the catheter;  
       
       
         inserting the distal end of the catheter into a chamber of a heart and causing the penetrating element to penetrate tissue inside the chamber;  
       
       
         supplying an angiogenic growth factor through the catheter to the penetrating element; and  
       
       
         with the penetrating element so penetrated, delivering the angiogenic growth factor to the tissue through the penetrating element. 
       
     
     
       54. The process of claim  53  further including: 
       
         removing the catheter after injecting the angiogenic growth factor, to leave the penetrating element implanted in the tissue. 
       
     
     
       55. The process of claim  53  wherein: 
       
         said providing a catheter with a penetrating element comprises providing said catheter with a helix disposed at the distal end of the catheter, and the angiogenic growth factor is supplied to the helix and injected into the tissue through the helix. 
       
     
     
       56. A process for treating the heart of a patient, including: 
       
         inserting a catheter device having a tissue penetrating element into a chamber of a heart;  
       
       
         providing an angiogenic growth factor through the catheter to the tissue penetrating element; and  
       
       
         causing a penetration of the penetrating element into tissue inside the chamber, and delivering the angiogenic growth factor from the penetrating element into the tissue. 
       
     
     
       57. The process of claim  56  further including: 
       
         removing the catheter device from the tissue penetrating element after delivering the angiogenic growth factor, to leave the tissue penetrating element implanted in the tissue.  
       
     
     
       58. The apparatus of claim  27  wherein: 
       
         said penetration of the penetrating element positions the proximal portion of the structure inside the heart. 
       
     
     
       59. The process of claim  40  wherein: 
       
         said delivering the biocompatible structure and said causing the penetration of the penetrating element comprise using a catheter adapted to support the biocompatible structure at its distal end. 
       
     
     
       60. The process of claim  53  further including: 
       
         after causing the penetration of the penetrating element, removing the catheter from the penetrating element to leave the penetrating element implanted in the surrounding tissue. 
       
     
     
       61. The apparatus of claim  27  wherein: 
       
         said penetrating element incorporates a controlled release matrix, and said providing the pharmacological agent to the penetrating element comprises providing the pharmacological agent to the controlled release matrix. 
       
     
     
       62. The process of claim  50  wherein: 
       
         said delivering an angiogenic growth factor includes providing a controlled release of the angiogenic growth liver over an extended period of time. 
       
     
     
       63. The apparatus of claim  51  further including: 
       
         a controlled release mechanism for delivering the angiogenic agent over an extended period of time. 
       
     
     
       64. The process of claim  53  wherein: 
       
         said delivering an angiogenic growth factor includes using a controlled release mechanism associated with at least one of the penetrating element and the catheter. 
       
     
     
       65. The process of claim  50  wherein: 
       
         at least part of said delivery device is coated with a controlled release matrix, and said delivering an angiogenic growth factor to the tissue comprises providing the angiogenic growth factor to the controlled release matrix. 
       
     
     
       66. The apparatus of claim  51  further including: 
       
         a controlled release matrix disposed along the tissue penetrating structure for supplying the angiogenic agent to the heart tissue. 
       
     
     
       67. The process of claim  53  wherein: 
       
         said penetrating element includes a controlled release matrix, and said supplying an angiogenic growth factor through the catheter to the penetrating element comprises providing the angiogenic growth factor to the controlled release matrix. 
       
     
     
       68. The process of claim  56  wherein: 
       
         said tissue penetrating element is coated with a controlled release matrix, and said delivering the angiogenic growth factor from the penetrating element into the tissue comprises delivering the angiogenic growth factor to the controlled release matrix. 
       
     
     
       69. An apparatus for locally modifying electrical action within the heart, comprising: 
       
         a biocompatible, electrically inactive, implantable device including a means for penetrating cardiac tissue to effect an implantation of the implantable device at a designated site in a heart, to modify electrical action in the cardiac tissue at the designated site; and  
       
       
         a catheter releasably coupled to the implantable device to allow a decoupling and withdrawal of the catheter after said implantation. 
       
     
     
       70. The apparatus of claim  69  further including: 
       
         an electrode means at a distal end of the catheter for sensing electrical action in the cardiac tissue before said implantation, to facilitate locating the designated site. 
       
     
     
       71. An apparatus for supplying a pharmacological agent locally to a depth within cardiac tissue, including: 
       
         a biocompatible, electrically inactive including a distally located tissue penetrating element adapted for penetration of cardiac tissue to a depth within surrounding cardiac tissue, and a proximal portion of the structure adapted to remain exposed outside of the cardiac tissue when the penetrating element is surrounded by the cardiac tissue, and wherein the structure, at least at said penetrating element, is adapted to deliver a pharmacological agent to the surrounding cardiac tissue; and  
       
       
         a delivery device releasably coupled to the biocompatible structure to allow a decoupling and withdrawal of the delivery device after said penetration. 
       
     
     
       72. The apparatus of claim  71  further including: 
       
         a fluid passage through the biocompatible structure, open to an exterior of the structure at said proximal portion and at said penetrating element. 
       
     
     
       73. The apparatus of claim  72  wherein: 
       
         said delivery device incorporates a lumen fluid coupled to the fluid passage at said proximal portion of the structure, to facilitate the supplying of the pharmacological agent from the lumen to the surrounding cardiac tissue via the fluid passage. 
       
     
     
       74. A process for delivering an angiogenic agent to a heart, including: 
       
         penetrating a delivery device into heart tissue;  
       
       
         delivering an angiogenic agent to the tissue through the delivery device; and  
       
       
         after so delivering the angiogenic agent, removing and withdrawing a proximal portion of the delivery device to leave a distal portion of the delivery device imbedded in the heart tissue. 
       
     
     
       75. An apparatus for delivering an angiogenic agent to the heart, including: 
       
         a catheter body having a proximal end, a distal end and a lumen between the proximal and distal ends;  
       
       
         an angiogenic agent in the lumen; and  
       
       
         a tissue penetrating structure releasably coupled to the distal end of the catheter body and adapted to deliver the angiogenic agent from the lumen into heart tissue. 
       
     
     
       76. A process for treating the heart of a patient, including: 
       
         providing a catheter and a penetrating element disposed at a distal end of the catheter;  
       
       
         inserting the distal end of the catheter into a chamber of the heart, and causing the penetrating element to penetrate tissue inside the chamber;  
       
       
         supplying an angiogenic agent through the catheter to the penetrating element;  
       
       
         injecting the angiogenic agent into the tissue through the penetrating element; and  
       
       
         after injecting the angiogenic agent, removing the catheter to leave the penetrating element penetrated within the tissue. 
       
     
     
       77. A process for treating the heart of a patient, including: 
       
         providing catheter device including a tissue penetrating element disposed at a distal end of the catheter device;  
       
       
         inserting at least a distal end region of the catheter device into a chamber of the heart;  
       
       
         providing an angiogenic agent through the catheter to the tissue penetrating element;  
       
       
         causing a penetration of the penetrating element into tissue inside to chamber, and delivering the angiogenic agent from the penetrating element into the tissue; and  
       
       
         decoupling the penetrating element from a remaining portion of the catheter device and removing said remaining portion from the chamber.