Implantable medical device sensing and selecting wireless ecg and intracardiac electrogram

Abstract

A CRM system enhances intracardiac electrogram-based arrhythmia detection using a wireless electrocardiogram (ECG), which is a signal sensed with implantable electrodes and approximating a surface ECG. In one embodiment, an intracardiac electrogram allows for detection of an arrhythmia, and the wireless ECG allows for classification of the detected arrhythmia by locating its origin. In another embodiment, the wireless ECG is sensed as a substitute signal for the intracardiac electrogram when the sensing of the intracardiac electrogram becomes unreliable. In another embodiment, a cardiac signal needed for a particular purpose is selected from one or more intracardiac electrograms and one or more wireless ECGs based on a desirable signal quality. In another embodiment, intracardiac electrogram-based arrhythmia detection and wireless ECG-based arrhythmia detection confirm with each other before indicating a detection of arrhythmia of a certain type.

1 . (canceled) 
     
     
         2 . A system, comprising:
 one or more cardiac electrodes configured to be implanted in or on the heart;   one or more subcutaneous electrodes configured to be implanted in subcutaneous tissue;   a first sensing circuit coupled to the one or more cardiac electrodes, the first sensing circuit configured to sense an intracardiac electrogram using the one or more cardiac electrodes;   a second sensing circuit coupled to the one or more subcutaneous electrodes, the second sensing circuit configured to sense a subcutaneous electrocardiogram using the one or more subcutaneous electrodes; and   a first arrhythmia detection circuit coupled to the first sensing circuit, the first arrhythmia detection circuit configured to detect an arrhythmia using a first arrhythmia detection methodology using the intracardiac electrogram; and   a second arrhythmia detection circuit coupled to the second sensing circuit, the second arrhythmia detection circuit configured to detect the arrhythmia using a second arrhythmia detection methodology using the subcutaneous electrocardiogram.   
     
     
         3 . The system of  claim 2 , further comprising an arrhythmia confirmation circuit coupled to the first and second arrhythmia detection circuits, wherein the arrhythmia confirmation circuit is configured to indicate a detection of the arrhythmia based upon the detection of the arrhythmia using the detection of the arrhythmia by the first and second arrhythmia detection circuits. 
     
     
         4 . The system of  claim 3 , wherein the arrhythmia confirmation circuit is configured to indicate a detection of the arrhythmia only when both the first arrhythmia detection circuit and the second arrhythmia detection circuit detect the arrhythmia. 
     
     
         5 . The system of  claim 3 , wherein the arrhythmia confirmation circuit is configured to indicate a detection of the arrhythmia only when the first arrhythmia detection circuit and the second arrhythmia detection circuit detect the same type of arrhythmia. 
     
     
         6 . The system of  claim 3 , wherein the arrhythmia confirmation circuit is configured to indicate a detection of the arrhythmia using a weighting factor of the first arrhythmia detection circuit and the second arrhythmia detection circuit. 
     
     
         7 . The system of  claim 2 , wherein the first arrhythmia detection methodology is the same as the second arrhythmia detection methodology. 
     
     
         8 . The system of  claim 2 , wherein the first arrhythmia detection methodology is different from the second arrhythmia detection methodology. 
     
     
         9 . The system of  claim 2 , further comprising an arrhythmia classification circuit configured to classify the arrhythmia detection by the first and second arrhythmia detection circuits. 
     
     
         10 . The system of  claim 2 , further comprising a therapy circuit configured to generate and deliver electrostimulation to the subject in response to the detection of the arrhythmia. 
     
     
         11 . A method for delivering therapy to treat an arrhythmia, the method comprising:
 sensing an intracardiac electrogram with a first sensing circuit using a plurality of cardiac electrodes configured to be implanted in or on a heart;   sensing a subcutaneous electrocardiogram with a second sensing circuit using a plurality of subcutaneous electrodes configured to be implanted in subcutaneous tissue;   detecting an arrhythmia using a first arrhythmia detection methodology using the sensed intracardiac electrogram;   detecting the arrhythmia using a second arrhythmia detection methodology using the sensed subcutaneous electrocardiogram; and   delivering a therapy to the heart based upon the detection of the arrhythmia with the first arrhythmia detection methodology and the second arrhythmia methodology.   
     
     
         12 . The method of  claim 11 , wherein the therapy is delivered to the heart when both the first arrhythmia detection methodology and the second arrhythmia detection methodology detect the arrhythmia. 
     
     
         13 . The method of  claim 11 , wherein the therapy is delivered to the heart when the first arrhythmia detection methodology and the second arrhythmia detection methodology detect the same type of arrhythmia. 
     
     
         14 . The method of  claim 11 , wherein the first arrhythmia detection methodology is the same as the second arrhythmia detection methodology. 
     
     
         15 . The method of  claim 11 , wherein the first arrhythmia detection methodology is different from the second arrhythmia detection methodology. 
     
     
         16 . A method for delivering therapy to treat an arrhythmia, the method comprising:
 detecting and classifying an arrhythmia using either (i) an intracardiac electrogram sensed using a plurality of cardiac electrodes configured to be implanted in or on a heart, or (ii) a subcutaneous electrocardiogram sensed using a plurality of subcutaneous electrodes configured to be implanted in subcutaneous tissue;   confirming the detection of the arrhythmia using the other of (i) the intracardiac electrogram sensed using the plurality of cardiac electrodes configured to be implanted in or on the heart, or (ii) the subcutaneous electrocardiogram sensed using the plurality of subcutaneous electrodes configured to be implanted in subcutaneous tissue; and   delivering a therapy to the heart based upon the confirmation of the detection of the arrhythmia.   
     
     
         17 . The method of  claim 16 , wherein a first arrhythmia detection methodology is used with the intracardiac electrogram and a second arrhythmia detection methodology is used with the subcutaneous electrocardiogram. 
     
     
         18 . The method of  claim 17 , wherein the first arrhythmia detection methodology is the same as the second arrhythmia detection methodology. 
     
     
         19 . The method of  claim 17 , wherein the first arrhythmia detection methodology is different from the second arrhythmia detection methodology. 
     
     
         20 . The method of  claim 17 , wherein the detection of the arrhythmia is confirmed when the same type of arrhythmia is detected with both the first arrhythmia detection methodology and the second arrhythmia detection methodology. 
     
     
         21 . The method of  claim 17 , wherein the detection of the arrhythmia is confirmed using a weighting factor.