Atrial interval based heart rate variability diagnostic for cardiac rhythm management system

Abstract

A cardiac rhythm management system acquires atrial heart rate variability data. The system provides a graphic or other indication of patient well-being based on the atrial heart rate variability data. Such atrial heart rate variability information provides an indication of the autonomic balance between the sympathetic and parasympathetic/vagal components of the autonomic nervous system. One example of the system also provides time-domain processing of frequency components of the atrial heart rate interval signal to obtain the indication of patient well-being.

What is claimed is:  
     
         1 . A method including: 
 detecting, over a time period, intrinsic atrial heart contractions;    measuring P-P intervals between the intrinsic atrial heart contractions;    calculating beat-to-beat P-P time differences between a pair of successive P-P intervals;    categorizing the P-P time differences based on at least one of: (1) a magnitude of at least one P-P interval in the pair of successive P-P intervals; and (2) an amount of the P-P time difference;    storing, over the time period, a categorized count of the P-P time differences; and    providing a diagnostic based on the stored categorized count of the P-P time differences.    
     
     
         2 . The method of  claim 1 , in which providing the diagnostic includes displaying the P-P time differences as a function of at least one of: (1) the magnitude of at least one P-P interval in the pair of successive P-P intervals; and (2) the amount of the P-P time difference.  
     
     
         3 . The method of  claim 1 , in which categorizing the P-P time differences includes categorizing the P-P time differences as a function of both of: (1) the magnitude of at least one P-P interval in the pair of successive P-P intervals; and (2) the amount of the P-P time difference.  
     
     
         4 . The method of  claim 1 , further including adjusting a cardiac rhythm management therapy based on at least one P-P time difference.  
     
     
         5 . The method of  claim 1 , further including disposing an atrial electrode in an atrium of a heart.  
     
     
         6 . A system including: 
 an atrial electrode configured for being associated with an atrium of a heart;    an atrial sense amplifier, including an atrial sense amplifier input coupled to the atrial electrode for receiving, over a time period, intrinsic atrial electrical depolarizations therefrom, and including an atrial sense amplifier output;    a P-P interval timer, including a P-P timer input coupled to the atrial sense amplifier output for receiving intrinsic atrial electrical depolarizations, and including a P-P timer output providing a P-P interval between successive atrial heart contractions;    a difference circuit, including a difference circuit input coupled to the P-P interval timer, and a difference circuit output providing a P-P time difference between a successive pair of P-P intervals; and    a controller, coupled to the P-P timer output for receiving the P-P intervals and also coupled to the difference circuit output for receiving the P-P time differences, the controller categorizing the P-P time differences based on at least one of: (1) a magnitude of at least one P-P interval in the pair of successive P-P intervals; and (2) an amount of the P-P time difference.    
     
     
         7 . The system of  claim 6 , further including a memory device, coupled to the controller, the memory device storing, over the time period, a categorized count of the P-P time differences.  
     
     
         8 . The system of  claim 7 , further including a display, communicatively coupled to the memory device, the display providing information associated with the P-P time differences.  
     
     
         9 . The system of  claim 8 , in which the display provides information associated with the categorized count of the P-P time differences displayed as a function of at least one of: (1) the magnitude of at least one P-P interval in the pair of successive P-P intervals; and (2) the amount of the P-P time difference.  
     
     
         10 . The system of  claim 9 , in which the display provides information associated with the categorized count of the P-P time differences displayed as a function of both of: (1) the magnitude of at least one P-P interval in the pair of successive P-P intervals; and (2) the amount of the P-P time difference.  
     
     
         11 . The system of  claim 7 , in which the controller categorizes the P-P time differences based on both of: (1) the magnitude of at least one P-P interval in the pair of successive P-P intervals; and (2) the amount of the P-P time difference.  
     
     
         12 . The system of  claim 7 , further including a therapy module providing therapy to the heart based on a comparison of an attribute of at least one P-P time difference to a predetermined criterion.