PMR device and method

Abstract

A catheter having an elongate shaft including a proximal and a distal end. The shaft includes a conductor. An electrode is disposed at the distal end of the shaft and is connected to the conductor. The electrode has a generally annular, cross-sectional shape. The annular shape defines an opening within the electrode. An insulator surrounds the conductor. In accordance with the method of the present invention, a crater wound can be formed through the endocardium and into the myocardium of a patient's heart. Collateral damage to the myocardium can be made by infusing pressurized fluid into the crater wound.

What is claimed is:  
     
         1 . A catheter assembly, comprising: 
 an elongate shaft having a proximal end and a distal end, and including a conductor;    an electrode disposed at the distal end of the shaft and connected to the conductor, the electrode having a generally annular transverse cross-sectional shape, the annular shape defining an opening within the electrode, the electrode having a distal end;    an insulator surrounding the conductor.    
     
     
         2 . A catheter assembly in accordance with  claim 1 , wherein a stop is disposed in the opening proximally a predetermined distance from the distal end of the electrode.  
     
     
         3 . A catheter assembly in accordance with  claim 1 , wherein the shaft defines a lumen in fluid communication with the opening.  
     
     
         4 . A catheter assembly in accordance with  claim 3 , further comprising a needle disposed within the opening and in fluid communication with the lumen.  
     
     
         5 . A catheter assembly in accordance with  claim 1 , wherein the insulator includes polyethylene.  
     
     
         6 . A catheter assembly in accordance with  claim 1 , wherein the insulator includes polyimide.  
     
     
         7 . A catheter assembly in accordance with  claim 1 , wherein the shaft includes a stainless steel hypotube.  
     
     
         8 . A catheter assembly in accordance with  claim 1 , wherein the shaft includes a Nitinol hypotube.  
     
     
         9 . A catheter assembly in accordance with  claim 1 , further comprising a radiofrequency generator connected to the conductor.  
     
     
         10 . A catheter assembly in accordance with  claim 1 , wherein the annular shape is generally circular.  
     
     
         11 . A catheter assembly in accordance with  claim 1 , wherein the annular shape is continuous.  
     
     
         12 . A catheter assembly in accordance with  claim 1 , wherein the annular shape is discontinuous.  
     
     
         13 . A catheter assembly in accordance with  claim 12 , wherein the annular shape is formed by a plurality of electrodes positioned in an array.  
     
     
         14 . A catheter assembly in accordance with  claim 1 , wherein the electrode includes a plurality of distally projecting members.  
     
     
         15 . A catheter assembly in accordance with  claim 14 , wherein the electrode is serrated to grab tissue.  
     
     
         16 . A catheter assembly in accordance with  claim 1 , further comprising a second electrode.  
     
     
         17 . A catheter assembly in accordance with  claim 16 , wherein the electrode comprises a needle.  
     
     
         18 . A method of performing PMR, comprising the steps of: 
 providing a catheter including an elongate shaft having a proximal end and a distal end, and a generally annularly shaped electrode disposed at the distal end;    advancing the electrode to proximate the endocardium of the patient's heart;    energizing the electrode; and    advancing the electrode into the myocardium to wound the myocardium.    
     
     
         19 . The method in accordance with  claim 18 , further comprising the step of providing a lumen through the shaft.  
     
     
         20 . The method in accordance with  claim 19 , further comprising the step of delivering contrast medium to the distal end through the lumen.  
     
     
         21 . The method in accordance with  claim 19 , further comprising the step of delivering a drug to the distal end through the lumen.  
     
     
         22 . The method in accordance with  claim 19 , further comprising the step of delivering saline to the distal end through the lumen.  
     
     
         23 . A method of performing PMR, comprising the steps of: 
 forming a hole through the endocardium and into the myocardium having a width and a depth, wherein the width of the hole is greater than the depth;    infusing a fluid into the hole.    
     
     
         24 . A catheter, comprising: 
 a shaft having a distal end and a proximal end; and    a radiopaque marker disposed proximate the distal end, the marker having an asymmetrical shape, such that the marker appears in mirror image when viewed from opposite sides of the shaft.