Radiopaque Marking of Lead Electrode Zone in a Continuous Conductor Construction

Abstract

A cardiac transvenous defibrillation lead has a continuous coil conductor within a layer of insulation. A portion of the coil conductor is exposed as a defibrillation electrode. In order to enhance fluoroscopic visualization of the exposed electrode during implant, the end of the exposed electrode is marked with a radiopaque element. The element may be in the form of an adhesive filled with radiopaque material that is used to backfill under the layer of insulation. Alternatively, a tube made of radiopaque material may be installed between the layer of insulation and the coil conductor.

1 . A transvenous defibrillation lead, comprising:
 a continuous coil conductor;   
       a layer of insulation over the coil conductor and providing for a distal portion of the coil conductor to be exposed as a defibrillation electrode; and
 a body of adhesive filled with a radiopaque material positioned as a backfill under the insulation layer at a location adjacent the proximal end of the exposed defibrillation electrode. 
 
     
     
         2 . The lead of  claim 1  wherein the radiopaque material is tantalum powder. 
     
     
         3 . The lead of  claim 1  wherein the radiopaque material is barium sulfate. 
     
     
         4 . A method of marking a lead to distinguish portions of electrode and non-electrode segments of the lead after implant, the method comprising:
 providing a layer of insulation over a continuous coil conductor; and   providing a body of adhesive filled with a radiopaque material positioned as a backfill under the insulation layer at a location of the electrode segment.   
     
     
         5 . The method of  claim 4  further comprising:
 determining the position of said portions of the electrode segment in the heart based on the radiopaque marking. 
 
     
     
         6 . The method of  claim 4  where said radiopaque marking is implemented to place at least one of said portions of the electrode segment in a specific zone of the heart for pacing and defibrillation procedures. 
     
     
         7 . The method of  claim 4  wherein the radiopaque material is tantalum powder. 
     
     
         8 . The method of  claim 4  wherein the radiopaque material is barium sulfate.