Substernal leadless electrical stimulation system

Abstract

Implantable leadless cardiac pacing systems and methods for providing substernal pacing using the leadless cardiac pacing systems are described. In one embodiment, an implantable leadless cardiac pacing system includes a housing, a first electrode on the housing, a second electrode on the housing, and a pulse generator within the housing and electrically coupled to the first electrode and the second electrode. The housing is implanted substantially within an anterior mediastinum of a patient and the pulse generator is configured to deliver pacing pulses to a heart of the patient via a therapy vector formed between the first and second electrodes.

1 . A medical device system comprising:
 a housing configured to be implanted within an anterior mediastinum of a patient;   one or more electrodes, wherein each electrode of the one or more electrodes represents a conductive portion of the housing; and   pulse generation circuitry within the housing and electrically coupled to the one or more electrodes, wherein the pulse generation circuitry is configured to deliver one or more pacing pulses to a heart of the patient via the one or more electrodes.   
     
     
         2 . The medical device system of  claim 1 , wherein the one or more electrodes comprises:
 a first electrode comprising a first conductive housing portion; and   a second electrode comprising a second conductive housing portion,   wherein the pulse generation circuitry is configured to deliver the one or more pacing pulses to the heart of the patient via a therapy vector formed between the first electrode and the second electrode.   
     
     
         3 . The medical device system of  claim 2 , wherein a spacer separates the first conductive housing portion and the second conductive housing portion, and wherein the spacer comprises a non-conductive housing portion. 
     
     
         4 . The medical device system of  claim 3 , wherein the one or more pacing pulses are a first one or more pacing pulses, wherein the therapy vector is a first therapy vector, wherein the spacer is a first spacer, and wherein the one or more electrodes further comprises:
 a third electrode comprising a third conductive housing portion; and   a fourth electrode comprising a fourth conductive housing portion,   wherein the pulse generation circuitry is configured to deliver a second one or more pacing pulses to the heart of the patient via a second therapy vector formed between the third electrode and the fourth electrode.   
     
     
         5 . The medical device system of  claim 4 , wherein a second spacer separates the third conductive housing portion and the fourth conductive housing portion, and wherein the second spacer comprises a non-conductive housing portion. 
     
     
         6 . The medical device system of  claim 4 , wherein the housing is configured to be implanted substantially within the anterior mediastinum such that the third electrode and the fourth electrode are located over a cardiac silhouette of an atrium of the heart as observed via an anterior-posterior (AP) fluoroscopic view of the heart. 
     
     
         7 . The medical device system of  claim 4 , wherein the housing is configured to be implanted substantially within the anterior mediastinum such that the pulse generation circuitry provides the first one or more pacing pulses to a ventricle of the heart via the first electrode and the second electrode and provides the second one or more pacing pulses to an atrium of the heart via the third electrode and the fourth electrode. 
     
     
         8 . The medical device system of  claim 1 , wherein the pulse generation circuitry is configured to provide at least one of bradycardia pacing, antitachycardia (ATP) pacing, or post-shock pacing to the patient via the one or more electrodes. 
     
     
         9 . The medical device system of  claim 1 , wherein the housing is configured to be implanted substantially within the anterior mediastinum such that the one or more electrodes are located over a cardiac silhouette of a ventricle of the heart as observed via an AP fluoroscopic view of the heart. 
     
     
         10 . The medical device system of  claim 1 , further comprising one or more anchoring mechanisms positioned along a length of the housing, wherein the one or more anchoring mechanisms are configured to anchor the housing within the anterior mediastinum of the patient such that the housing is physically isolated from a pericardium of the patient. 
     
     
         11 . The medical device system of  claim 1 , wherein the housing is a first housing, wherein the one or more electrodes are a first one or more electrodes, wherein the pulse generation circuitry is first pulse generation circuitry, wherein the one or more pacing pulses are a first one or more pacing pulses, and wherein the medical device system further comprises:
 a second housing configured to be implanted within an anterior mediastinum of a patient;   a second one or more electrodes, wherein each electrode of the second one or more electrodes represents a conductive portion of the second housing; and   second pulse generation circuitry within the second housing and electrically coupled to the second one or more electrodes, wherein the second pulse generation circuitry is configured to deliver a second one or more pacing pulses to a heart of the patient via the second one or more electrodes.   
     
     
         12 . The medical device system of  claim 11 , wherein the therapy vector is a first therapy vector, and wherein the second one or more electrodes comprises:
 a third electrode comprising a third conductive housing portion; and   a fourth electrode comprising a fourth conductive housing portion,   wherein the second pulse generation circuitry is configured to deliver the second one or more pacing pulses to the heart of the patient via a second therapy vector formed between the third electrode and the fourth electrode.   
     
     
         13 . The medical device system of  claim 12 , wherein a second spacer separates the third conductive housing portion and the fourth conductive housing portion, and wherein the second spacer comprises a non-conductive housing portion. 
     
     
         14 . The medical device system of  claim 12 , wherein the first housing and the second housing are configured to be implanted substantially within the anterior mediastinum of the patient such that the first one or more pacing pulses are delivered to a first chamber of the heart via the first electrode and the second electrode of the first housing and the second one or more pacing pulses are delivered to a second chamber of the heart via the third electrode and the fourth electrode of the second housing. 
     
     
         15 . The medical device system of  claim 14 , further comprising:
 first communication circuitry within the first housing; and   second communication circuitry within the second housing,   wherein the first communication circuitry transmits a telemetry communication to the second communication circuitry to coordinate delivering the first one or more pacing pulses and the second one or more pacing pulses.   
     
     
         16 . The medical device system of  claim 11 , further comprising one or more anchoring mechanisms positioned along a length of the second housing, wherein the one or more anchoring mechanisms are configured to anchor the second housing within the anterior mediastinum of the patient such that the second housing is physically isolated from the pericardium of the patient. 
     
     
         17 . The medical device system of  claim 12 , wherein the first housing and the second housing are configured to be implanted substantially within the anterior mediastinum of the patient such that the first electrode and the second electrode of the first housing sense electrical signals of a first chamber of the heart and the third electrode and the fourth electrode of the second housing sense electrical signals of a second chamber of the heart. 
     
     
         18 . The medical device system of  claim 1 , wherein the pulse generator is configured to deliver pacing pulses having pulse amplitudes within a range from 1 Volt (V) to 20 V. 
     
     
         19 . A medical device system comprising:
 a medical device comprising:
 a housing configured to be implanted within an anterior mediastinum of a patient; 
 one or more electrodes, wherein each electrode of the one or more electrodes represents a conductive portion of the housing; and 
 pulse generation circuitry within the housing and electrically coupled to the one or more electrodes, wherein the pulse generation circuitry is configured to deliver one or more pacing pulses to a heart of the patient via the one or more electrodes; and 
   processing circuitry configured to control the pulse generation circuitry to deliver the one or more pacing pulses to the heart of the patient via the one or more electrodes.   
     
     
         20 . A method comprising:
 forming a housing configured to be implanted within an anterior mediastinum of a patient;   forming one or more electrodes, wherein each electrode of the one or more electrodes represents a conductive portion of the housing; and   forming pulse generation circuitry within the housing and electrically coupled to the one or more electrodes, wherein the pulse generation circuitry is configured to deliver one or more pacing pulses to a heart of the patient via the one or more electrodes.