Leadless Cardiac Stimulation Systems

Abstract

Various configurations of systems that employ leadless electrodes to provide pacing therapy are provided. In one example, a system that provides multiple sites for pacing of myocardium of a heart includes wireless pacing electrode assemblies that are implantable at sites proximate the myocardium using a percutaneous, transluminal, catheter delivery system. Also disclosed are various configurations of such systems, wireless electrode assemblies, and delivery catheters for delivering and implanting the electrode assemblies.

1 . A leadless pacing electrode assembly comprising: 
 a passive wireless receiver; and    two or more electrodes attached to the passive wireless receiver to generate an excitation pulse when the passive wireless receiver receives energy from a magnetic field.    
   
   
       2 . The leadless pacing electrode assembly of  claim 1 , wherein the passive wireless receiver comprises a permeable core and a coil surrounding the permeable core.  
   
   
       3 . The leadless pacing electrode assembly of  claim 2 , wherein the two or more electrodes comprise two ring electrodes located at opposed ends of the permeable core.  
   
   
       4 . The leadless pacing electrode assembly of  claim 3 , wherein the two ring electrodes are mounted around the permeable core at opposed ends of the permeable core.  
   
   
       5 . The leadless pacing electrode assembly of  claim 4 , wherein the pacing electrode assembly is approximately 5 millimeters in length and the two ring electrodes are approximately 3 millimeters in diameter.  
   
   
       6 . The leadless pacing electrode assembly of  claim 1 , wherein the pacing electrode assembly is movable through a 9 French delivery catheter.  
   
   
       7 . The leadless pacing electrode assembly of  claim 1 , further comprising an attachment mechanism secured near a first end of the electrode assembly.  
   
   
       8 . The leadless pacing electrode assembly of  claim 7 , wherein the attachment mechanism includes a helical tine.  
   
   
       9 . The leadless pacing electrode assembly of  claim 7 , wherein the attachment mechanism includes a plurality of adjustable tines operable to be extended from a first end of the electrode assembly.  
   
   
       10 . The leadless pacing electrode assembly of  claim 7 , further comprising a detachment mechanism near a second end of the electrode assembly.  
   
   
       11 . The leadless pacing electrode assembly of  claim 10 , wherein the detachment mechanism includes a threaded fitting.  
   
   
       12 . A leadless pacing electrode assembly comprising: 
 a passive wireless receiver;    a pair of spaced electrodes; and    means for providing an excitation pulse between the pair of spaced electrodes.    
   
   
       13 . The leadless pacing electrode assembly of  claim 12 , further comprising at least one fastener to penetrate through an interior surface of a heart chamber and into a myocardial wall, wherein at least one of the pair of spaced electrodes is positioned in the myocardial wall when the fastener penetrates through the interior surface of the heart chamber and into the myocardial wall.  
   
   
       14 . The leadless pacing electrode assembly of  claim 13 , wherein the fastener is selected from the group consisting of a tine, a screw, a barb, and a hook.  
   
   
       15 . The leadless pacing electrode assembly of  claim 12 , wherein the excitation pulse from the excitation pulse comprises a voltage pulse amplitude greater than 0.5 Volts and a pulse duration of approximately 0.4 msec.  
   
   
       16 . A leadless pacing electrode assembly comprising: 
 a passive wireless receiver;    first and second electrodes attached to the passive wireless receiver to deliver the excitation pulses to the heart tissue when the passive wireless receiver receives energy from a magnetic field controlled by an external source, wherein the first and second electrodes are directly activated by the passive wireless receiver via an internal circuit that is free of a dedicated energy storage component; and    at least one fastener to penetrate through an interior surface of a heart chamber and into a myocardial wall, at least one of the first and second electrodes is positioned in the myocardial wall when the fastener penetrates through the interior surface of the heart chamber and into the myocardial wall.    
   
   
       17 . The leadless pacing electrode assembly of  claim 16 , wherein the passive wireless receiver comprises a permeable core and a coil surrounding the permeable core.  
   
   
       18 . The leadless pacing electrode assembly of  claim 16 , wherein the pacing electrode assembly is movable through a 9 French delivery catheter.  
   
   
       19 . The leadless pacing electrode assembly of  claim 16 , wherein the fastener is selected from the group consisting of a tine, a screw, a barb, and a hook.  
   
   
       20 . leadless pacing electrode assembly of  claim 16 , wherein the first and second electrodes deliver the excitation pulses to the heart tissue with a voltage pulse amplitude greater than 0.5 Volts and a pulse duration of approximately 0.4 msec.