Multi-electrode apparatus and method for treatment of congestive heart failure

Abstract

An apparatus and method for treatment of congestive heart failure from the right side of the heart. An implantable cardiac stimulation system with a multi-electrode lead having three or more selectable electrodes, together with apparatus for identifying an optimal subset of electrodes, apparatus for shaping a propagating wave front, and apparatus for modifying the intrinsic ventricular cardiac activation sequence, or generating simultaneous or near simultaneous pacing pulses to the septum or right ventricular outflow tract during ventricular systole in order to improve left ventricular cardiac efficiency and reduce mitral regurgitation in patients with dilated cardiomyopathy. A three dimensional map of electrode placement may be calculated. A sub set of the available electrodes in the right side of the heart is selected for stimulation such that septal motion during systole is reduced or the mitral valve area is stiffened to reduce mitral regurgitation.

1 . An apparatus for treating congestive heart failure comprising a multi-electrode lead, said multi-electrode lead having at least three selectable electrodes, 
 a cardiac stimulator in the body of said patient, said cardiac stimulator being connected to said multi-electrode lead,    means for selecting a subset of said electrodes for stimulating the heart such that stimulation through said set of electrodes improves cardiac performance, and    means for stimulating the heart through said subset of electrodes.    
     
     
         2 . The apparatus of  claim 1  further comprising means for selecting a set of electrodes lying on the right septal wall.  
     
     
         3 . The apparatus of  claim 3  further comprising means for stimulating substantially all of the ventricular septum within at least the first 10 per cent of ventricular contraction time.  
     
     
         4 . The apparatus of  claim 2  further comprising means for stimulating at said set of electrodes to stiffen the septum in a sequence such that substantially all of the septum stiffens substantially simultaneously.  
     
     
         5 . The apparatus of  claim 2  further comprising means for selecting a set of electrodes lying on the septal wall by identifying a set of electrodes close to a line connecting two electrodes that are known to lie on the septal wall.  
     
     
         6 . The apparatus of  claim 1  wherein said multi-electrode lead has sufficient electrodes deployable on the right ventricular septal wall such that at least fifty per cent of the right ventricular wall could be stimulated within the first ten percent of the ventricular contraction time.  
     
     
         7 . The apparatus of  claim 6  wherein said electrodes are within 8 mm of each other.  
     
     
         8 . The apparatus of  claim 6  wherein the electrodes are within 4 mm of each other.  
     
     
         9 . The apparatus of  claim 1  further comprising means for determining a three dimensional position for each electrode.  
     
     
         10 . The apparatus of  claim 1  further comprising means for developing a plurality of template patterns of wave fronts passing said electrodes and means for distinguishing between intrinsic and ectopic wave fronts by comparing sensed wave fronts to said template patterns.  
     
     
         11 . An implantable cardiac stimulator for treating congestive heart failure comprising 
 an implantable lead having at least three electrodes,    a cardiac stimulator connectable to said lead to place said electrodes in electrical communication with said stimulator;    at least one detector coupled to said electrodes for detecting electrical phenomenon in the patient's body;    a timer connected to said detector for timing at least one elapsed time between electrical phenomena detected at said electrodes;    at least one logical template of an expected pattern of detected electrical phenomenon at said electrodes,    a comparator comparing said detected electrical phenomenon and said elapsed times associated with said phenomenon to said logical template, and    an output circuit providing a therapy to said patient in response to said comparison.    
     
     
         12 . The implantable cardiac stimulator of  claim 11  further comprising a logical model in said cardiac stimulator representing locations of said electrodes in a patient's body.  
     
     
         13 . The implantable cardiac stimulator of  claim 11  further comprising a time-out circuit, said time out circuit turning off said timer whenever a second electrical phenomenon has not occurred within a selected period of time after a first phenomenon.  
     
     
         14 . The implantable cardiac stimulator of  claim 13  wherein the selected period of time is set based on electrode spacing and on expected conduction velocities.  
     
     
         15 . The implantable cardiac stimulator according to  claim 11  further comprising a logical template of a normal pattern and at least one logical template of an ectopic pattern.  
     
     
         16 . The implantable cardiac stimulator according to  claim 15  further comprising a circuit identifying an ectopic beat whenever a series of electric phenomenon is first detected at an electrode other than a selected first electrode.  
     
     
         17 . The implantable cardiac stimulator according to  claim 16  further comprising memory storing a template for identified ectopic beats.  
     
     
         18 . The implantable cardiac stimulator of  claim 11  further comprising circuit means for stimulating the heart through at least some of said at least three electrodes and means for selecting as a stimulating electrode that electrode which produces a pattern of electric phenomenon most closely resembling a normal template.  
     
     
         19 . The implantable cardiac stimulator of  claim 18  further comprising means for identifying fast conduction associated with stimulation through a patient's Purkinje system.  
     
     
         20 . The implantable cardiac stimulator of  claim 18  further comprising means for measuring cardiac output and means for comparing relative cardiac output resulting from stimulation at each of said at least some electrodes and wherein said means for selecting a stimulating electrode is responsive to said means for measuring cardiac output to select as stimulating electrode the electrode optimizing cardiac output.