Heart Wall Ablation/Mapping Catheter and Method

Abstract

Steerable electrophysiology catheters for use in mapping and/or ablation of accessory pathways in myocardial tissue of the heart wall and methods of use thereof are disclosed. The catheter comprises a catheter body and handle, the catheter body having a proximal section and a distal section and manipulators that enable the deflection of a distal segment of the distal tip section with respect to the independently formed curvature of a proximal segment of the distal tip section through a bending or knuckle motion of an intermediate segment between the proximal and distal segments. A wide angular range of deflection within a very small curve or bend radius in the intermediate segment is obtained. At least one distal tip electrode is preferably confined to the distal segment which can have a straight axis extending distally from the intermediate segment. The curvature of the proximal segment and the bending angle of the intermediate segment are independently selectable. The axial alignment of the distal segment with respect to the nominal axis of the proximal shaft section of the catheter body can be varied between substantially axially aligned (0° curvature) in an abrupt knuckle bend through a range of about −90° to about +180° within a bending radius of between about 2.0 mm and 7.0 mm and preferably less than 5.0 mm. The proximal segment curve can be independently formed in a range of about −180° through about +270° with respect to the axis of the proximal shaft section to provide an optimum angular orientation of the distal electrode(s). The distal segment can comprise a highly flexible elongated distal segment body and electrode(s) that conform with the shape and curvature of the heart wall.

1 . A catheter for ablation and/or mapping of the heart wall comprising:
 an elongated catheter body having proximal and distal ends and a catheter body axis, the catheter body further comprising a catheter body proximal section joined at a proximal section distal end with a deflectable catheter body distal section;   said distal section including a curvable proximal segment, a distal segment and a bendable intermediate segment having a predetermined intermediate segment length joined at an intermediate segment proximal end with a curvable proximal segment distal end and joined at an intermediate segment distal end with the distal segment, the intermediate segment capable of bending in a knuckle bend having a radius in the range of about 2.0 mm through 7.0 mm through a bend angle range of about −90° to about +180° with respect to the catheter body axis at the intermediate segment proximal end;   at least one electrode positioned along the distal segment;   a handle at the proximal end of the catheter body;   a conductor extending along the catheter body between said electrode and the handle;   a knuckle bend wire coupled to the distal segment and extending proximally through the bendable intermediate segment, the curvable proximal segment, and the proximal section of the catheter body to a knuckle bend wire proximal end in the handle;   a knuckle bend manipulator coupled to the knuckle bend wire proximal end and mounted for movement to the handle enabling selective extension and retraction of the knuckle bend wire to induce a bend in the bendable intermediate segment;   a curve deflection wire coupled to the distal end of the proximal segment and extending proximally through the curvable proximal segment and the proximal section of the catheter body to a curve deflection wire proximal end in the handle; and   a proximal curve manipulator coupled to the curve deflection wire proximal end and mounted for movement to the handle enabling selective extension and retraction of the curve deflection pull wire to induce a curve in the curvable proximal segment,   whereby selective adjustment of the knuckle bend and proximal curve manipulators induce bends in said bendable intermediate segment and curves in said proximal segment that are independent of one another.   
     
     
         2 . The catheter of  claim 1 , further comprising a first incompressible wire coil having a first incompressible wire coil lumen and extending from a first coil proximal end at the catheter body proximal end to a first coil distal end at the junction of the intermediate segment proximal end and the distal end of the proximal segment, a proximal section of said knuckle bend wire extending through said first incompressible wire coil lumen, whereby the first incompressible wire coil prevents inducement of a curve in the proximal segment and proximal section upon retraction of the knuckle bend wire within the first incompressible wire coil lumen by manipulation of the knuckle bend manipulator. 
     
     
         3 . The catheter of  claim 2 , further comprising a second incompressible wire having a second incompressible coil lumen coil and extending from a second coil proximal end at the catheter body proximal end to a second coil distal end at the junction of the proximal segment proximal end and the distal end of the proximal section, a proximal section of said curve deflection wire extending through said second incompressible coil lumen, whereby the second incompressible wire coil prevents inducement of a curve in the proximal section upon retraction of the curve deflection wire within the second incompressible coil lumen by manipulation of the proximal curve manipulator. 
     
     
         4 . The catheter of  claim 3 , wherein said first incompressible wire coil is contained floating within a first lumen of said catheter body enabling inducement of a bend in the intermediate segment by distal extension of the knuckle bend wire therethrough effecting an extension of the length of the catheter body without inducing an extension of the length of said first incompressible wire coil. 
     
     
         5 . The catheter of  claim 4 , wherein the first coil proximal end abuts a surface of a stop at the junction of the handle and the catheter body proximal end that the knuckle bend wire passes through that prevents proximal retraction of the first coil proximal end when the knuckle bend wire is retracted proximally through the first coil wire lumen and allows the first incompressible wire coil to move distally within the first lumen when the knuckle bend wire is extended distally through the first coil wire lumen. 
     
     
         6 . The catheter of  claim 4 , wherein the second incompressible wire coil is contained floating within a second lumen of said catheter body enabling inducement of a curvature in the proximal segment by distal extension of the curve deflection wire therethrough effecting an extension of the length of the catheter body without inducing an extension of the length of said second incompressible wire coil 
     
     
         7 . The catheter of  claim 3 , wherein the second incompressible wire coil is contained floating within a second lumen of said catheter body enabling inducement of a curvature in the proximal segment by distal extension of the curve deflection wire therethrough effecting an extension of the length of the catheter body without inducing an extension of the length of said second incompressible wire coil 
     
     
         8 . The catheter of  claim 7 , wherein the second coil proximal end abuts a surface of a stop at the junction of the handle and the catheter body proximal end that the curve deflection wire passes through that prevents proximal retraction of the second coil proximal end when the curve deflection wire is retracted proximally through the second coil wire lumen and allows the second incompressible wire coil to move distally within the second lumen when the curve deflection wire is extended distally through the second coil wire lumen. 
     
     
         9 . The catheter of  claim 7 , wherein the second coil proximal end abuts a surface of a stop at the junction of the handle and the catheter body proximal end that the curve deflection wire passes through that prevents proximal retraction of the second coil proximal end when the curve deflection wire is retracted proximally through the second coil wire lumen and allows the second incompressible wire coil to move distally within the second lumen when the curve deflection wire is extended distally through the second coil wire lumen and when the knuckle bend wire is extended distally through the first coil wire lumen. 
     
     
         10 . The catheter of  claim 2 , wherein said first incompressible wire coil is contained floating within a first lumen of said catheter body enabling inducement of a bend in the intermediate segment by distal extension of the knuckle bend wire therethrough effecting an extension of the length of the catheter body without inducing an extension of the length of said first incompressible wire coil. 
     
     
         11 . The catheter of  claim 1 , wherein the knuckle bend wire is formed of a superelastic alloy that is resistant to kinking when retracted to form a bend in the bendable intermediate segment. 
     
     
         12 . The catheter of  claim 1 , wherein the knuckle bend wire and the curve deflection wire extend through the proximal section and the curvable proximal segment and the knuckle bend wire extends through the bendable intermediate segment in a common, off-axis, radius extending from the catheter body axis, whereby the bend induced in the bendable intermediate segment and the curve induced in the curvable proximal segment are in a common plane with respect to the catheter body axis. 
     
     
         13 . The catheter of  claim 12 , wherein the curve induced in the proximal segment is in the range of about −180° to about +270° with respect to the catheter body axis at the junction of the proximal section with the proximal segment. 
     
     
         14 . The catheter of  claim 1 , wherein the knuckle bend wire and the curve deflection wire extend through the proximal section and the curvable proximal segment and the knuckle bend wire extends through the bendable intermediate segment in a common, off-axis, radius extending from the catheter body axis, whereby the bend induced in the bendable intermediate segment upon retraction proximally of the knuckle bend wire and the curve induced in the curvable proximal segment upon retraction proximally of the curve deflection wire are in a common plane with respect to the catheter body axis and in a common direction. 
     
     
         15 . The catheter of  claim 1 , wherein the knuckle bend wire and the curve deflection wire extend through the proximal section and the curvable proximal segment and the knuckle bend wire extends through the bendable intermediate segment in a common, off-axis, radius extending from the catheter body axis, whereby the bend induced in the bendable intermediate segment upon extension distally of the knuckle bend wire and the curve induced in the curvable proximal segment upon retraction proximally of the curve deflection wire are in a common plane with respect to the catheter body axis but in differing directions. 
     
     
         16 . The catheter of  claim 1 , wherein the knuckle bend wire and the curve deflection wire extend through the proximal section and the curvable proximal segment and the knuckle bend wire extends through the bendable intermediate segment in a common, off-axis, radius extending from the catheter body axis, whereby the bend induced in the bendable intermediate segment upon retraction proximally of the knuckle bend wire and the curve induced in the curvable proximal segment upon extension distally of the curve deflection wire are in a common plane with respect to the catheter body axis but in differing directions. 
     
     
         17 . The catheter of  claim 1 , further comprising:
 a third movable manipulator mounted to the handle; and   an axially rotatable lateral deflection wire coupling the proximal segment to the third movable manipulator so that selected movement of the third movable manipulator causes the lateral deflection wire to exert a lateral deflection force on said proximal segment causing the curve in said proximal segment to be deflected laterally.