Cardiac mapping instrument with shapeable electrode

Abstract

An instrument including an elongated shaft and a non-conductive handle is disclosed. The shaft defines a proximal section and a distal section. The distal section forms an electrically conductive tip. Further, the shaft is adapted to be transitionable from a straight state to a first bent state. The shaft is capable of independently maintaining the distinct shapes associated with the straight state and the first bent state. The handle is rigidly coupled to the proximal section of the shaft. The instrument is useful for epicardial pacing and/or mapping of the heart for temporary pacing on a beating heart, for optimizing the placement of ventricular leads for the treatment of patients with congestive heart failure and ventricular dysynchrony and/or for use in surgical ablation procedures.

1 . A system for pacing the heart comprising: 
 an instrument including: 
 an elongated shaft defining a proximal section and a distal section, wherein the distal section forms an electrically conductive rounded tip, and further wherein the shaft is adapted to be transitionable from a straight state to a first bent state, the shaft independently maintaining distinct shapes in the straight state and the first bent state, and a non-conductive handle rigidly coupled to the proximal section of the shaft; wherein an exterior of the shaft distal the handle and proximal the distal section is electrically non-conductive;  
 a grounding electrode; and  
 an energy source electrically connected to the tip and the grounding electrode, wherein the energy source comprises stimulation energy for pacing the heart.  
   
     
     
         2 . The system of  claim 1 , wherein the tip of the instrument defines a uniform radius of curvature.  
     
     
         3 . The system of  claim 1 , wherein in the straight state, the shaft of the instrument defines a linear axis, and further wherein in the first bent state, a portion of the shaft is deflected relative to the linear axis.  
     
     
         4 . The system of  claim 3 , wherein the shaft of the instrument is adapted to be transitionable to, and independently maintain a shape in, any direction relative to the linear axis.  
     
     
         5 . The system of  claim 1 , wherein the shaft of the instrument is capable of being bent at a multiplicity of points along a length thereof.  
     
     
         6 . The system of  claim 1 , wherein the shaft of the instrument is adapted to be transitionable to, and independently maintain a shape of, a second bent state different from the first bent state.  
     
     
         7 . The system of  claim 1 , wherein the instrument is adapted for stimulating cardiac tissue through a chest of a patient.  
     
     
         8 . The system of  claim 7 , wherein the cardiac tissue is atrial tissue.  
     
     
         9 . The system of  claim 7 , wherein the cardiac tissue is ventricular tissue.  
     
     
         10 . The system of  claim 7 , wherein the instrument is adapted for stimulating cardiac tissue endocardially through a chest of a patient.  
     
     
         11 . The system of  claim 7 , wherein the instrument is adapted for stimulating cardiac tissue epicardially through a chest of a patient.  
     
     
         12 . The system of  claim 1 , wherein the shaft of the instrument includes: 
 an elongated electrode body forming the proximal section and the distal section, the electrode body being directly coupled to the handle; and    an electrical insulator surrounding a portion of the electrode body.    
     
     
         13 . The system of  claim 12 , wherein the electrode body is formed of an electrically conductive, malleable material.  
     
     
         14 . The system of  claim 12 , wherein the electrical insulator is configured to conform to the electrode body in the straight state and the first bent state.  
     
     
         15 . The system of  claim 1 , wherein the shaft of the instrument comprises a joint adapted to permit the distal section of the shaft to move relative to the proximal section of the shaft.  
     
     
         16 . The system of  claim 15 , wherein the joint is a ball bearing joint adapted to allow the distal section of the shaft to rotate relative to the proximal section of the shaft.  
     
     
         17 . The system of  claim 15 , wherein the joint includes a pin such that the joint allows the distal section of the shaft to swivel relative to the proximal section of the shaft.  
     
     
         18 . The system of  claim 15 , further comprising a remote actuator configured to selectively control the joint.  
     
     
         19 . The system of  claim 1 , wherein the instrument is adapted for sensing a depolarization wave.  
     
     
         20 . The system of  claim 1 , wherein the grounding electrode is a needle electrode.  
     
     
         21 - 46 . (canceled)  
     
     
         47 . A method of performing an ablation procedure, the method comprising: 
 providing a first instrument including an elongated shaft and a handle, the shaft defining a proximal section rigidly coupled to the handle, a distal section forming an electrically conductive tip;    positioning the tip of the first instrument through a patient's chest;    applying ablation energy to the tip of the first instrument while contacting cardiac tissue;    creating an ablation lesion to isolate an area of cardiac tissue;    providing a second instrument including an elongated shaft and a handle, the shaft defining a proximal section rigidly coupled to the handle, a distal section forming an electrically conductive tip;    positioning the tip of the second instrument through a patient's chest; and    applying stimulation energy to the tip of the second instrument while contacting the area of isolated cardiac tissue to assess transmurality of the ablation lesion.    
     
     
         48 . The method of  claim 47 , wherein the first instrument further comprises an internal lumen extending from the proximal section of the shaft and in fluid communication with at least one passage formed in the distal section of the shaft.  
     
     
         49 . The method of  claim 48 , further comprising: 
 dispensing conductive fluid from the internal lumen of the shaft via the at least one passage.    
     
     
         50 . The method of  claim 47 , wherein the ablation energy is radiofrequency energy.  
     
     
         51 . A method of performing an ablation procedure, the method comprising: 
 providing an instrument including an elongated shaft and a handle, the shaft defining a proximal section rigidly coupled to the handle, a distal section forming an electrically conductive tip;    positioning the tip through a patient's chest;    applying ablation energy to the tip while contacting cardiac tissue;    creating an ablation lesion to isolate an area of cardiac tissue;    stopping the application of ablation energy to the tip;    repositioning the tip; and    applying stimulation energy to the tip while contacting the area of isolated cardiac tissue to assess transmurality of the ablation lesion.    
     
     
         52 . The method of  claim 51 , wherein the instrument further comprises an internal lumen extending from the proximal section of the shaft and in fluid communication with at least one passage formed in the distal section of the shaft.  
     
     
         53 . The method of  claim 52 , further comprising: 
 dispensing conductive fluid from the internal lumen of the shaft via the at least one passage while applying ablation energy to the tip.    
     
     
         54 . The method of  claim 51 , wherein the ablation energy is radiofrequency energy.  
     
     
         55 . A method of performing a left sided epicardial lead placement procedure, the method comprising: 
 providing an instrument including an elongated shaft and a handle, the shaft defining a proximal section rigidly coupled to the handle, a distal section forming an electrically conductive tip;    positioning the tip through a patient's chest to contact a first area of epicardial tissue of the patient's left ventricle;    applying stimulation energy to the patient's right ventricle;    recording the time at which a depolarization wave is sensed over the left ventricle following stimulation of the right ventricle;    repositioning the tip to contact a second area of epicardial tissue of the patient's left ventricle;    reapplying stimulation energy to the patient's right ventricle;    recording the time at which the depolarization wave is sensed over the left ventricle following restimulation of the right ventricle;    placing an epicardial lead in contact with the area of tissue that had the longest time interval at which the depolarization wave was sensed over the left ventricle following stimulation of the right ventricle.    
     
     
         56 . A method of performing an ablation procedure, the method comprising: 
 providing an instrument including an elongated shaft and a handle, the shaft defining a proximal section rigidly coupled to the handle, a distal section forming an electrically conductive tip;    advancing the tip of the instrument through a patient's chest and into the patient's coronary sinus;    positioning the tip of the instrument in the patient's coronary sinus between an existing lesion encircling at least a portion of the patient's pulmonary veins and the annulus of the patient's mitral valve;    applying ablation energy to the tip of the instrument while the tip is positioned in the coronary sinus; and    creating an ablation lesion in an area of cardiac tissue surrounding the tip.