Method and apparatus for arrhythmia classification using atrial signal mapping

Abstract

An implantable medical device senses a plurality of electrograms from substantially different atrial locations, detects regional depolarizations from the electrograms, and analyzes timing relationships among the regional depolarizations. The timing relationships provide a basis for effective therapy control and/or prognosis of certain cardiac disorders. In one embodiment, an atrial activation sequence is mapped to show the order of occurrences of the regional depolarizations during an atrial depolarization for classifying a detected tachyarrhythmia by its origin. In another embodiment, conduction time between two atrial locations is measured for monitoring the development of an abnormal atrial conditions and/or the effect of a therapy.

1 . A lead for electrically coupling an implantable medical device to a heart having a right atrium (RA) connected to a vena cava, a left atrium (LA), a left ventricle (LV), a sinoatrial (SA) node, an atrial septum, a coronary sinus, a coronary vein, the lead comprising: 
 an elongate lead body having a primary end and a distal end, the primary end coupled to a connector configured for connecting to the implantable medical device;    first, second, and third conductors disposed within the lead body and coupled to the connector;    an LA electrode coupled to the first conductor and configured for placement in the coronary sinus or coronary vein near the LA;    an atrial septal electrode coupled to the second conductor and configured for placement in the coronary sinus near the atrial septum; and    a high RA (HRA) electrode coupled to the third conductor and configured for placement in the RA or the superior vena cava near the SA node.    
   
   
       2 . The lead of  claim 1 , further comprising: 
 a fourth conductor disposed within the lead body and coupled to the connector; and    an LV electrode coupled to the fourth conductor and the distal end of the lead body and configured for placement in the coronary vein over the LV.    
   
   
       3 . The lead of  claim 2 , wherein the LA electrode, the atrial septal electrode, and the HRA electrode are each a ring electrode incorporated onto the elongate lead body.  
   
   
       4 . A lead for electrically coupling an implantable medical device to a heart having a right atrium (RA) connected to a superior vena cava, a sinoatrial (SA) node, and an atrial septum, the lead comprising: 
 an elongate lead body having a primary end and a distal end, the primary end coupled to a connector configured for connecting to the implantable medical device;    first and second conductors disposed within the lead body and coupled to the connector;    a high RA (HRA) electrode coupled to the first conductor and configured for placement in the RA or the superior vena cava near the SA node; and    a second RA electrode coupled to the second conductor and configured for placement in the RA.    
   
   
       5 . The lead of  claim 4 , wherein the second RA electrode is an atrial septal electrode configured for placement in the RA near the atrial septum.  
   
   
       6 . The lead of  claim 5 , wherein the HRA electrode comprises a ring electrode incorporated onto the elongate lead body.  
   
   
       7 . The lead of  claim 4 , further comprising: 
 a third conductor disposed within the lead body and coupled to the connector; and    a third RA electrode coupled to the third conductor and configured for placement in the RA.    
   
   
       8 . The lead of  claim 7 , wherein the second RA electrode and the third RA electrode are each an atrial septal electrode configured for placement in the RA near the atrial septum.  
   
   
       9 . A cardiac rhythm management system coupled to a heart having a right atrium (RA) connected to a superior vena cava, a left atrium (LA), a left ventricle (LV), a sinoatrial (SA) node, an atrial septum, a coronary sinus, and a coronary vein, the system comprising: 
 one or more leads including a plurality of atrial electrodes; and    an implantable medical device coupled to the one or more leads, the implantable medical device including: 
 a sensing circuit configured to sense a plurality of atrial electrograms using the plurality of atrial electrodes;  
 an arrhythmia detection circuit configured to detect tachyarrhythmia; and  
 an arrhythmia classification circuit configured to classify the detected tachyarrhythmia, the arrhythmia classification circuit including: 
 an atrial signal mapping module configured to map an atrial activation sequence using the sensed plurality of atrial electrograms, the atrial activation sequence indicative of an order of regional depolarizations during an atrial depolarization; and  
 an atrial pattern analyzer configured to classify the detected tachyarrhythmia using the atrial activation sequence.  
 
   
   
   
       10 . The system of  claim 9 , wherein the one or more leads comprises a first lead including: 
 an LA electrode configured for placement in the coronary sinus or coronary vein near the LA;    an atrial septal electrode configured for placement in the coronary sinus near the atrial septum; and    a high RA (HRA) electrode configured for placement in the RA or the superior vena cava near the SA node,    wherein the sensing circuit is configured to sense an RA electrogram via the HRA electrode, an LA electrogram via the LA electrode, and an atrial septal electrogram via the atrial septal electrode, and wherein the atrial signal mapping module is configured to map an atrial activation sequence using the RA electrogram, the LA electrogram, and the atrial septal electrogram.    
   
   
       11 . The system of  claim 10 , wherein the implantable medical device comprises: 
 an event detection circuit configured to detect an RA event from the RA electrogram and an LA event from the LA electrogram during an atrial depolarization; and    an inter-atrial interval measurement circuit configured to measure a time interval between the RA event and the LA event.    
   
   
       12 . The system of  claim 11 , wherein the implantable medical device further comprises one or more of an atrial enlargement detection circuit and an atrial conduction disturbance detection circuit, the atrial enlargement detection circuit configured to detect abnormal enlargement of at least one atrium using the inter-atrial interval, the atrial conduction disturbance detection circuit configured to detect atrial conduction disturbance using the inter-atrial interval.  
   
   
       13 . The system of  claim 12 , wherein the implantable medical device comprises the atrial enlargement detection circuit, and the atrial enlargement detection circuit comprises a comparator including a first input to receive the inter-atrial interval, a second input to receive a predetermined threshold interval, and an output to indicate the abnormal enlargement of at least one atrium when the inter-atrial interval exceeds the predetermined threshold interval.  
   
   
       14 . The system of  claim 12 , wherein the implantable medical device comprises the atrial conduction disturbance detection circuit, and the atrial conduction disturbance detection circuit is configured to detect a variance of the inter-atrial interval and comprises a comparator including a first input to receive the variance of the inter-atrial interval, a second input to receive a predetermined threshold variance, and an output to indicate the atrial conduction disturbance when the variance of the inter-atrial interval exceeds the predetermined threshold variance.  
   
   
       15 . The system of  claim 10 , wherein the first lead further comprises an LV electrode configured for placement in the coronary vein over the LV, the sensing circuit is further configured to sense an LV electrogram via the LV electrode, and the atrial pattern analyzer is configured to classify the tachyarrhythmia using the atrial activation sequence and the LV electrogram.  
   
   
       16 . The system of  claim 9 , wherein the one or more leads comprises a first lead and a second lead, the first lead including a high RA (HRA) electrode configured for placement in the RA or the superior vena cava near the SA node and a second RA electrode configured for placement in the RA, the second lead including an LA electrode configured for placement in the coronary sinus or coronary vein near the LA, wherein the sensing circuit is configured to sense an RA electrogram via the HRA electrode, an LA electrogram via the LA electrode, and an atrial septal electrogram via the second atrial electrode, and wherein the atrial signal mapping module is configured to map an atrial activation sequence using the RA electrogram, the LA electrogram, and the atrial septal electrogram.  
   
   
       17 . The system of  claim 16 , wherein the implantable medical device further comprises: 
 an event detection circuit configured to detect an RA event from the RA electrogram and an LA event from the LA electrogram during an atrial depolarization; and    an inter-atrial interval measurement circuit configured to measure a time interval between the RA event and the LA event.    
   
   
       18 . The system of  claim 17 , wherein the implantable medical device further comprises one or more of an atrial enlargement detection circuit and an atrial conduction disturbance detection circuit, the atrial enlargement detection circuit configured to detect abnormal enlargement of at least one atrium using the inter-atrial interval, the atrial conduction disturbance detection circuit configured to detect atrial conduction disturbance using the inter-atrial interval.  
   
   
       19 . The system of  claim 18 , wherein the implantable medical device comprises the atrial enlargement detection circuit, and the atrial enlargement detection circuit comprises a comparator including a first input to receive the inter-atrial interval, a second input to receive a predetermined threshold interval, and an output to indicate the abnormal enlargement of at least one atrium when the inter-atrial interval exceeds the predetermined threshold interval.  
   
   
       20 . The system of  claim 18 , wherein the implantable medical device comprises the atrial conduction disturbance detection circuit, and the atrial conduction disturbance detection circuit is configured to detect a variance of the inter-atrial interval and comprises a comparator including a first input to receive the variance of the inter-atrial interval, a second input to receive a predetermined threshold variance, and an output to indicate the atrial conduction disturbance when the variance of the inter-atrial interval exceeds the predetermined threshold variance.  
   
   
       21 . The system of  claim 16 , wherein the second lead further comprises an LV electrode configured for placement in the coronary vein over the LV, wherein the sensing circuit is further configured to sense an LV electrogram via the LV electrode, and wherein the atrial pattern analyzer is configured to classify the tachyarrhythmia using the atrial activation sequence and the LV electrogram.  
   
   
       22 . The system of  claim 9 , wherein the atrial pattern analyzer comprises at least two of: 
 a right atrial pattern matching module configured to detect a supraventricular tachyarrhythmia of a right atrial origin by comparing the atrial activation sequence to a predetermined right atrial pattern template sequence;    a left atrial pattern matching module configured to detect an supraventricular tachyarrhythmia of a left atrial origin by comparing the atrial activation sequence to a predetermined left atrial pattern template sequence; and    an atrial septal pattern matching module configured to detect one of a supraventricular tachyarrhythmia of atrial septal origin and a ventricular tachyarrhythmia by comparing the atrial activation sequence to a predetermined atrial septal pattern template sequence.