Directional defibrillation leads and methods

Abstract

Systems, methods, and devices for delivering stimulating energy with a lead having a directional defibrillation electrode are disclosed. The lead includes a directional defibrillation electrode configured for implantation on or near the inner surface of a rib or the inner surface of the innermost intercostal muscle and having an electrically active portion configured to emanate stimulating energy from an exposed portion of the directional defibrillation electrode toward the pericardium and the heart. The lead also has an electrically insulating portion around at least part of the circumference of the lead. The electrically insulating portion is configured to insulate surrounding muscle and/or tissue from the stimulating energy when the lead is implanted in the patient.

We claim: 
     
         1 . A lead for implantation in a patient, the lead comprising:
 a directional defibrillation electrode configured for implantation on or near the inner surface of a rib or the inner surface of the innermost intercostal muscle and having an electrically active portion configured to emanate stimulating energy from an exposed portion of the directional defibrillation electrode toward the pericardium and the heart; and   an electrically insulating portion around at least part of a circumference of the lead, the electrically insulating portion configured to insulate surrounding muscle and/or tissue from the stimulating energy when the lead is implanted in the patient.   
     
     
         2 . The lead of  claim 1 , wherein the electrically insulating portion surrounds the entire circumference of the lead but leaves exposed a distal tip of the lead so that the directional defibrillation electrode is at the distal tip of the lead. 
     
     
         3 . The lead of  claim 1 , wherein the directional defibrillation electrode is electrically insulated on all sides other than one exposed side. 
     
     
         4 . The lead of  claim 1 , wherein the directional defibrillation electrode is located away from a distal tip of the lead. 
     
     
         5 . The lead of  claim 4 , wherein the directional defibrillation electrode is electrically insulated over a significant portion of the lead's circumference. 
     
     
         6 . The lead of  claim 4 , wherein, at the location of the directional defibrillation electrode, approximately 50% of the circumference of the lead is electrically insulating, leaving approximately 50% of the circumference of the lead exposed. 
     
     
         7 . The lead of  claim 4 , wherein, at the location of the directional defibrillation electrode, approximately 75% of the circumference of the lead is electrically insulating, leaving approximately 25% of the circumference of the lead exposed. 
     
     
         8 . A method of implanting a lead in a patient, the lead having a directional defibrillation electrode and an electrically insulating portion around at least part of a circumference of the lead, the directional defibrillation electrode having an electrically active portion configured to emanate stimulating energy from an exposed portion of the directional defibrillation electrode, the method comprising:
 placing the lead in the patient such that the electrically insulating portion of the lead is on or near an inner surface of a rib or an inner surface of the innermost intercostal muscle of the patient and the electrically insulating portion insulates the intercostal muscle from the stimulating energy; and   directing the directional defibrillation electrode of the lead toward a heart of the patient.   
     
     
         9 . The method of  claim 8 , wherein placing the lead in the patient further comprises implanting the lead through an intercostal space of the patient in a region of a cardiac notch. 
     
     
         10 . The method of  claim 8 , wherein the placing of the lead results in the electrically insulating portion touching the intercostal muscle. 
     
     
         11 . The method of  claim 8 , wherein placing the lead further includes the lead being proximate the heart, but not being physically in contact with the heart or a pericardium of the heart. 
     
     
         12 . A cardiac defibrillation system comprising:
 a lead implanted in a patient through an intercostal space and on or near an inner surface of a rib or an inner surface of an innermost intercostal muscle in a region of a cardiac notch of the patient and not physically in contact with the heart or the pericardium of the heart, the lead comprising:
 a directional defibrillation electrode having an electrically active portion configured to emanate stimulating energy from an exposed portion of the directional electrode toward the pericardium and the heart; and 
 an electrically insulating portion around at least part of a circumference of the lead, the lead implanted such that the electrically insulating portion insulates surrounding muscle and/or tissue from the stimulating energy. 
   
     
     
         13 . The cardiac defibrillation system of  claim 12 , wherein the electrically insulating portion surrounds the entire circumference of the lead but leaves exposed a distal tip of the lead so that the directional defibrillation electrode is at the distal tip of the lead. 
     
     
         14 . The cardiac defibrillation system of  claim 12 , wherein the directional defibrillation electrode is electrically insulated on all sides other than one exposed side. 
     
     
         15 . The cardiac defibrillation system of  claim 12 , wherein the directional electrode is located away from a distal tip of the lead. 
     
     
         16 . The cardiac defibrillation system of  claim 15 , wherein the directional defibrillation electrode is electrically insulated over a significant portion of the lead's circumference. 
     
     
         17 . The cardiac defibrillation system of  claim 15 , wherein, at the location of the directional defibrillation electrode, approximately 50% of the circumference of the lead is electrically insulating, leaving approximately 50% of the circumference of the lead exposed. 
     
     
         18 . The cardiac defibrillation system of  claim 15 , wherein, at the location of the directional defibrillation electrode, approximately 75% of the circumference of the lead is electrically insulating, leaving approximately 25% of the circumference of the lead exposed.