Summation anodal pacing to complement multisite stimulation

Abstract

A device and method for cardiac pacing is disclosed in which anodal pacing of the left ventricle is provided. Anodal pacing occurs when an anodal surface area is sufficiently small to create an area of hyper-polarization of the myocardial cell membrane. This creates a virtual cathode at a location remote from the anode. The virtual cathode results in depolarization of the heart in a manner similar to the virtual cathode at the true fixed cathode. In addition a device and method for summation anodal pacing is provided in which one anode is common between two or more cathodes. This results in hyperpolarization of a larger segment of the myocardium as compared to non-summation anodal pacing and thereby forms a larger virtual electrode to enable capture of localized, discrete cardiac structures such as the bundle of His or the very proximal portions of the right and left bundles.

I claim: 
     
       1. A device for applying an electrical current to a heart, the device comprising:
 a current source; 
 a plurality of leads which are connected to the current source, wherein the leads include first, second, and third leads that are connectable to a right atrium of a heart, a right ventricle of the heart, and a left ventricle of the heart, respectively; wherein each of the leads has at least one electrode and at least one of the leads has at least two electrodes, wherein at least one of the electrodes serves as a cathode and at least one of the electrodes serves as an anode, wherein a surface area of at least one of the electrodes is sized sufficiently small to cause anodal capture, wherein the current source is controlled to deliver solely cathodal stimulation to at least one electrode, wherein at least one other electrode is a return electrode and the stimulation creates an area of hyper-polarization of the myocardial cell membrane and resultant modal capture of a portion of the heart via the return electrode, wherein the return electrode is a pacing electrode, and wherein cathodal stimulation is simultaneous with anodal capture that occurs solely as a consequence of the cathodal stimulation of another electrode. 
 
     
     
       2. The device of  claim 1 , wherein an anode receives current from at least two cathodes. 
     
     
       3. The device of  claim 1 , wherein the third lead includes one or more electrodes that serves as a cathode and one or more electrode that serves as the anode. 
     
     
       4. The device of  claim 1 , wherein the second lead includes a proximal electrode that is at least seven times the surface area of a tip electrode. 
     
     
       5. A method of cardiac pacing, the method comprising the steps of:
 coupling first, second, and third leads to a right atrium of a heart, a right ventricle of a heart, and a left ventricle of the heart, respectively, wherein each of the leads has at least one electrode and at least one of the leads has at least two electrodes, and wherein at least one electrode serves as a cathode and at least one electrode serves as an anode; and 
 delivering solely cathodal stimulus current to at least one electrode wherein at least one other electode is a return electrode and the stimulus current creates an area of depolarization of one part of the myocardial cell membrane and resultant cathodal stimulation and hyper-polarization of another part the myocardial cell membrane and resultant anodal capture of another portion of the heart via the return electrode, wherein the return electrode is a pacing electrode, wherein the cathodal stimulation and the anodal capture of the another portion of the heart are simultaneous, and wherein and the anodal capture occurs solely as a consequence of the cathodal stimulation of another electrode. 
 
     
     
       6. The method of  claim 5 , further comprising the steps of:
 coupling, a unipolar or bipolar lead to a left atrium; and 
 delivering a stimulus current to the unipolar or bipolar lead from the current source. 
 
     
     
       7. The method of  claim 5 , wherein an anode of the third lead serves as the anode to two cathodes. 
     
     
       8. The method of  claim 5 , wherein the current is delivered to the first, second, and third leads at different times. 
     
     
       9. The method of  claim 8 , wherein the current is delivered to the second lead at least seventy milliseconds after delivering current to the first lead. 
     
     
       10. The method of  claim 5 , further comprising coupling a fourth lead to a left atrium of the heart, and wherein the stimulus current is a sub-threshold stimulus current is applied to the third lead simultaneously with and purely as a consequence of stimulation of one of the first and fourth leads. 
     
     
       11. The method of  claim 5 , wherein the third lead is multipolar and has at least three electrodes, and wherein the stimulus current is delivered to the electrodes of the third lead at different times. 
     
     
       12. A method of cardiac pacing, the method comprising the steps of:
 coupling a first lead, a second lead, and a third lead to a right atrium of a heart, a right ventricle of the heart, and a left ventricle of the heart, respectively, wherein each of the leads has at least one electrode and at least one of the leads has a plurality of electrodes, and wherein at least one electrode serves as a cathode and at least one electrode serves as an anode; and 
 applying a solely cathodal stimulus current to at least one electrode wherein at least one electrode is used as a return electrode and the stimulus current creates an area of hyper-polarization of the myocardial cell membrane and resultant modal capture of a portion of the heart via the return electrode, wherein the return electrode is a pacing electrode, wherein an anode of the third lead serves as the anode to two or more cathodes, and wherein anodal capture of the portion of the heart as a result of the stimulation occurs solely as a consequence of the cathodal stimulation of another electrode. 
 
     
     
       13. A method of cardiac pacing, the method comprising the steps of:
 coupling a first lead, a second lead, and a third lead to a right atrium of a heart, a right ventricle of the heart, and a left ventricle of the heart, respectively, wherein each of the leads has at least one electrode and at least one of the leads has a plurality of electrodes, and wherein at least one electrode serves as a cathode and at least one electrode serves as an anode; and 
 delivering solely cathodal stimulus current to at least one electrode wherein at least one other electrode is a return electrode and the stimulus creates an area of depolarization of one part of the myocardial cell membrane and resultant cathodal stimulation and hyper-polarization of another part the myocardial cell membrane and resultant anodal capture of a portion of the heart via return electrode, wherein the return electrode is a pacing electrode, wherein the cathodal stimulation and the anodal capture of the portion of the heart as a result of stimulation are simultaneous and the anodal capture occurs solely as a consequence of the cathodal stimulation of another electrode, and wherein the stimulus current is delivered to the electrodes at different times. 
 
     
     
       14. A method of cardiac pacing, the method comprising the steps of:
 providing a device comprising:
 a current source; 
 a plurality of leads which are connected to the current source, wherein each lead is connected to at least one of a right atrium of a heart, a right ventricle of the heart, a left atrium of the heart, and a left ventricle of the heart; 
 wherein at least one electrode is associated with each of the leads and at least two electrodes are associated with at least one of the leads, wherein at least one electrode serves as a cathode and at least one electrode serves as an anode, wherein an anodal surface area is sized to cause anodal capture; and 
 
 delivering solely cathodal stimulus current to at least one electrode wherein at least one other electrode is a return electrode and the stimulus creates an area of depolarization of one part of the myocardial cell membrane and resultant cathodal stimulation and hyper-polarization of another part the myocardial cell membrane and resultant anodal capture of another portion of the heart via the return electrode, wherein the return electrode is a pacing electrode, wherein the cathodal stimulation and the anodal capture are simultaneous and the anodal capture of the another portion of the heart as a result of the stimulation occurs solely as a consequence of the cathodal stimulation of another electrode. 
 
     
     
       15. The method of  claim 14 , wherein at least two cathodes stimulate one anode. 
     
     
       16. The method of  claim 14 , wherein the lead that is connected to the left ventricle is multipolar and comprises a plurality of electrodes that serve as cathodes and a plurality of electrodes that serve as anodes. 
     
     
       17. The method of  claim 14 , wherein an electrode that is connected to the left ventricle serves as the anode for an electrode of the right ventricle and an electrode of the left ventricle both serving as cathodes. 
     
     
       18. The method of  claim 14 , wherein an electrode on the right ventricle serves as the anode for at least one electrode of the left ventricle serving as a cathode. 
     
     
       19. The method of  claim 14 , further comprising delivering current to the leads from the current source such that the left ventricle is stimulated earlier than the right ventricle, the electrodes of the left ventricle serving as cathodes are stimulated earlier than the electrodes of the left ventricle serving as anodes, and such that the electrodes of the left ventricle serving as anodes receive current from the electrodes of the right ventricle serving as cathodes. 
     
     
       20. The method of  claim 14 , further comprising delivering current to the leads from the current source such that the right ventricle is stimulated earlier than the left ventricle, the electrodes of the left ventricle serving as anodes are stimulated earlier than the electrodes of the left ventricle serving as cathodes, and such that the electrodes of the left ventricle serving as anodes receive current from the electrodes of the right ventricle serving as cathodes. 
     
     
       21. The method of  claim 5 , further comprising the step of inserting a fourth lead into a left atrium of the heart, and wherein anodal pacing is performed on the left atrium and the right atrium of the heart. 
     
     
       22. A device for applying an electrical current to a heart, the device comprising:
 a current source;   a plurality of leads which are connected to the current source,
 wherein the leads include first, second, and third leads that are connectable to a right atrium of a heart, a right ventricle of the heart, and a left ventricle of the heart, respectively; 
 wherein each of the leads has at least one electrode and at least the third lead has at least two electrodes, 
 wherein at least one of the electrodes serves as a cathode and at least one of the electrodes serves as an anode, 
 wherein a surface area of at least one of the electrodes is sized sufficiently small to cause anodal capture, 
 wherein the current source is controlled to deliver solely cathodal stimulation to at least one electrode, 
 wherein at least one other electrode is a return electrode, 
 wherein the stimulation creates an area of hyper-polarization of the myocardial cell membrane and resultant anodal capture of a portion of the heart via the return electrode, 
 wherein the return electrode is a pacing electrode, and 
 wherein cathodal stimulation is simultaneous with anodal capture that occurs solely as a consequence of the cathodal stimulation of another electrode. 
   
     
     
       23. A device for applying an electrical current to a heart, the device comprising:
 a current source;   a plurality of leads which are connected to the current source,
 wherein the leads include first, second, and third leads that are connectable to a right atrium of a heart, a right ventricle of the heart, and a left ventricle of the heart, respectively; 
 wherein each of the leads has at least one electrode and the third lead has at least four electrodes, 
 wherein at least one of the electrodes serves as a cathode and at least one of the electrodes serves as an anode, 
 wherein a surface area of at least one of the electrodes is sized sufficiently small to cause anodal capture, 
 wherein the current source is controlled to deliver solely cathodal stimulation to at least one electrode, 
 wherein at least one other electrode is a return electrode, 
 wherein the stimulation creates an area of hyper-polarization of the myocardial cell membrane and resultant anodal capture of a portion of the heart via the return electrode, 
 wherein the return electrode is a pacing electrode, and 
 wherein cathodal stimulation is simultaneous with anodal capture that occurs solely as a consequence of the cathodal stimulation of another electrode. 
   
     
     
       24. The device of  claim 23 , wherein the third lead is a quadripolar lead having four electrodes. 
     
     
       25. The device of  claim 24 , wherein two of the electrodes on the quadripolar lead serve as anodes and two of the electrodes on the quadripolar lead serve as cathodes. 
     
     
       26. The device of  claim 23 , wherein an electrode on the second lead and two of the electrodes on the third lead serve as cathodes, and wherein one of the electrodes on the third lead serves as a common anode for a cathode on the second lead and two cathodes on the third lead. 
     
     
       27. The device of  claim 23 , wherein the second lead is a bipolar lead having a proximal electrode and a tip electrode, and wherein the proximal electrode has a surface area that is at least 7 times a surface area of the tip electrode. 
     
     
       28. A device for applying an electrical current to a heart, the device comprising:
 a current source;   a plurality of leads which are connected to the current source,   wherein the leads include first, second, and third leads that are connectable to a right atrium of a heart, a right ventricle of the heart, and a left ventricle of the heart, respectively;   wherein each of the leads has at least one electrode and the third lead has at least four electrodes,   wherein at least one of the electrodes serves as a cathode and at least one of the electrodes serves as an anode,   wherein a surface area of at least one of the electrodes is sized sufficiently small to cause anodal capture,   wherein the current source is controlled to deliver solely cathodal stimulation to at least one electrode,   wherein at least one other electrode is a return electrode,   wherein the stimulation creates an area of hyper-polarization of the myocardial cell membrane and resultant anodal capture of a portion of the heart via the return electrode,   wherein the return electrode is a pacing electrode,   wherein cathodal stimulation is simultaneous with anodal capture that occurs solely as a consequence of the cathodal stimulation of another electrode,   wherein the third lead is a quadripolar lead having four electrodes,   wherein at least one electrode of the third lead serves as a cathode and at least one electrode of the third lead serves as an anode,   wherein the second lead is a bipolar lead having a proximal electrode and a tip electrode, and   wherein the proximal electrode on the bipolar lead has a surface area that is at least 7 times a surface area of the tip electrode on the bipolar lead.   
     
     
       29. A method of cardiac pacing, the method comprising the steps of:
 coupling first, second, and third leads to a right atrium of a heart, a right ventricle of a heart, and a left ventricle of the heart, respectively, wherein each of the first and second leads has at least one electrode and at the third lead has at least two electrodes;   delivering solely cathodal stimulus current to at least one electrode wherein at least one other electrode is a return electrode and the stimulus creates an area of depolarization of one part of the myocardial cell membrane and resultant cathodal stimulation and hyper-polarization of another part the myocardial cell membrane and resultant anodal capture of a portion of the heart via the return electrode, wherein the return electrode is a pacing electrode, wherein the cathodal stimulation and the anodal capture of the portion of the heart as a result of stimulation are simultaneous and the anodal capture occurs solely as a consequence of the cathodal stimulation of another electrode, and wherein the stimulus current is delivered to the electrodes at different times.   
     
     
       30. The method of  claim 29 , wherein the third lead is a quadripolar lead having four electrodes. 
     
     
       31. A method of cardiac pacing, the method comprising the steps of:
 providing a device comprising:
 a current source; 
 a plurality of leads which are connected to the current source, wherein each lead is connected to at least one of a right atrium of a heart, a right ventricle of the heart, a left atrium of the heart, and a left ventricle of the heart, wherein each of the first and second leads has at least one electrode and the third lead has at least four electrodes; 
 wherein at least one electrode is associated with each of the leads and at least two electrodes are associated with at least one of the leads, wherein at least one electrode serves as a cathode and at least one electrode serves as an anode, 
   wherein an anodal surface area is sized to cause anodal capture; and   delivering solely cathodal stimulus current to at least one electrode wherein at least one other electrode is a return electrode and the stimulus creates an area of depolarization of one part of the myocardial cell membrane and resultant cathodal stimulation and hyper-polarization of another part the myocardial cell membrane and resultant anodal capture of another portion of the heart via the return electrode, wherein the return electrode is a pacing electrode, wherein the cathodal stimulation and the anodal capture are simultaneous and the anodal capture of the another portion of the heart as a result of the stimulation occurs solely as a consequence of the cathodal stimulation of another electrode.   
     
     
       32. The method of  claim 31 , wherein the third lead is a quadripolar lead having four electrodes.