Atrial ablation catheter and method of use

Abstract

An atrial ablation catheter and methods for its use. The endocardial catheter includes an electrode array particularly adapted to locate and ablate foci of arrhythmia which are required for sustained atrial fibrillation is provided. The array is easily deployed and retracted from the catheter, and presents a distally oriented electrode array that can be pressed against the wall of the atrium.

1 . An ablation catheter comprising: 
 an outer catheter tube;    an inner catheter tube slidably disposed within the outer catheter tube, said inner catheter tube having a distal end adapted for insertion into a vessel of the body;    a floating tube slidably disposed relative to the inner catheter tube; and    an electrode array comprising a plurality of resilient arms, each arm having a proximal arm segment fixed to the inner catheter tube and a distal arm segment fixed to the floating tube, whereby the electrode array may be compressed by longitudinal translation of the outer catheter tube relative to the inner catheter tube, and the floating tube longitudinally translates relative to the inner tube to accommodate longitudinal movement of the distal end of the resilient arms in response to compression of the electrode array;    a plurality of electrodes disposed on each of the distal arm segments of the array.    
   
   
       2 . The ablation catheter of  claim 1 , wherein: 
 the floating tube is disposed at least partially within the distal end of the inner catheter tube.    
   
   
       3 . The ablation catheter of  claim 1 , wherein: 
 the electrode array is resiliently movable from a small diameter configuration to a large diameter configuration, and in the large diameter configuration each proximal arm segment resiliently bends radially outwardly from the inner catheter tube, and each distal arm segment bends radially inwardly toward the longitudinal axis of the catheter from a bend point connecting the proximal arm segment to the distal arm segment, creating an acute angle between each distal arm segment and its associated proximal arm segment.    
   
   
       4 . The ablation catheter of  claim 1 , wherein: 
 the electrode array is resiliently movable from a small diameter configuration and a large diameter configuration, and in the large diameter configuration each proximal arm segment resiliently bends radially outwardly from the inner catheter tube, and each distal arm segment bends radially inwardly and proximally toward the longitudinal axis of the catheter from a bend point connecting the proximal arm segment to the distal arm segment.    
   
   
       5 . The ablation catheter of  claim 1 , wherein: 
 the electrode array is resiliently movable from a small diameter configuration and a large diameter configuration, and in the large diameter configuration each proximal arm segment resiliently bends radially outwardly from the inner catheter tube, and each distal arm segment bends radially inwardly and proximally toward the longitudinal axis of the catheter from a bend point connecting the proximal arm segment to the distal arm segment, and said electrode arms are further deformable upon pressing the array against a surface to position the distal arm segments into a substantially planar arrangement.    
   
   
       6 . The ablation catheter of  claim 4  in the small diameter configuration, the distal arm segments are restrained within a segment of the outer catheter tube which is distal to the proximal arm segments, and extend distally from the bend point.  
   
   
       7 . The ablation catheter of  claim 4  in the small diameter configuration, the distal arm segments are folded inwardly so as to be disposed proximate the proximal arm segments and extend proximally from the bend point.  
   
   
       8 . The ablation of  claim 5  further comprising a control wire fixed to the floating tube and operable from the proximal end of the catheter to pull the floating tube proximally.  
   
   
       9 . The ablation catheter of  claim 1 , wherein: 
 the floating tube comprises a stainless steel coil.    
   
   
       10 . An ablation catheter comprising: 
 a catheter;    an electrode array disposed on the distal end of the catheter, said electrode array comprising a plurality of resilient arms, each arm having a proximal arm segment and a distal arm segment resiliently or rotatably joined to each other at a bend point, whereby the electrode array may be retained in a small diameter configuration within the catheter and released to assume a large diameter configuration, wherein the large diameter configuration comprises the proximal arm segments bent radially outwardly from the catheter with the distal arm segments extending radially inwardly from the proximal arm segments; and    at least one electrode disposed on each of the distal arm segments of the array;    
   
   
       11 . The ablation catheter of  claim 10  wherein the distal arm segments tend proximally from the bend point in the large diameter configuration.  
   
   
       12 . The ablation catheter of  claim 10  wherein the distal arm segments tend proximally from the bend point in the large diameter configuration and tend distally from the bend point in the small diameter configuration.  
   
   
       13 . The ablation catheter of  claim 10  further comprising: 
 a tube slidably disposed within the catheter and fixed to the distal arm segments.    
   
   
       14 . The ablation catheter of  claim 10  further comprising: 
 a tube slidably disposed within the catheter and fixed to the distal arm segments, wherein the tube comprises a coil.    
   
   
       15 . The ablation catheter of  claim 10  wherein, in the small diameter configuration, the distal arm segments are restrained within a segment of the outer catheter tube which is distal to the proximal arm segments, and extend distally from the bend point.  
   
   
       16 . The ablation catheter of  claim 10  wherein, in the small diameter configuration, the distal arm segments are folded inwardly so as to be disposed proximate the proximal arm segments and extend proximally from the bend point.  
   
   
       17 . The ablation of  claim 16  further comprising a control wire fixed to the floating tube and operable from the proximal end of the catheter to pull the floating tube proximally.  
   
   
       18 . A method of treating atrial fibrillation comprising: 
 providing a catheter having an electrode array disposed on the distal end thereof, said electrode array comprising: 
 a plurality of resilient arms, each arm having a proximal arm segment and a distal arm segment connected by a bend point, said arms being resiliently biased to bend at an acute angle at the bend points, and a plurality of electrodes disposed on each of the distal arm segments;  
 wherein said electrode array has an expanded configuration in which each proximal arm segment resiliently bends radially outwardly from the catheter, and each distal arm segment bends radially inwardly and proximally toward the longitudinal axis of the catheter from the bend point;  
   restraining the electrode array in a small diameter configuration within the outer catheter tube;    inserting the electrode array into the left atrium of the heart of a patient;    withdrawing the outer tube from the electrode array, and allowing the electrode array to expand to its expanded configuration;    pressing the distal arm segments of the electrode array against an area of the heart wall;    sensing electrical signals of the heart wall through the electrodes of the electrode array;    upon determining that the array is disposed over an arrhythmogenic focus in the left atrium, passing energy through the electrode array to ablate a portion of the heart wall;    moving the electrode array as desired to additional areas of the heart wall and repeating the sensing and ablating steps as desired to treat atrial fibrillation.    
   
   
       19 . The method of  claim 18  further comprising the steps of: 
 providing a return electrode on the catheter, proximal to the electrodes of the electrode array;    pressing the electrode array against the posterior wall of the left atrium of the heart to sense electrical signals;    operating at least one electrode of the array in monopolar mode in conjunction with the return electrode ablate a portion of the posterior wall of the left atrium.    
   
   
       20 . The method of  claim 19  further comprising the steps of: 
 providing a return electrode on the catheter, proximal to the electrodes of the electrode array;    pressing the electrode array against an ostium of a pulmonary vein opening to the left atrium of the heart to sense electrical signals;    operating at least one electrode of the array in monopolar mode in conjunction with the return electrode to ablate a portion of the left atrium wall surrounding a pulmonary vein.