Trending of conduction time for optimization of cardiac resynchronization therapy in cardiac rhythm management system

Abstract

A method of optimizing cardiac resynchronization therapy delay over a patient's full range of activity for use in operating an implantable cardiac pacing device and such a device are disclosed. The method includes measuring selected conduction time between selected sites in the heart for a plurality of beats and logging the values on a periodic repeating programmable basis to produce cumulative data and constructing a current template of conduction time in relation to one or more other sensed parameters of interest over a desired range of patient activity levels. The current template is used to derive suggested optimum pacing timing.

1 - 53 . (canceled)  
   
   
       54 . A method of optimizing cardiac resynchronization therapy over a patient's full range of activity for use in operating an implantable cardiac pacing device comprising the steps of: 
 (a) trending one or more selected cardiac conduction times over a range of corresponding activity levels of a patient;    (b) optimizing the timing of a related pacing pulse based on said trending of one or more conduction times; and    (c) wherein said trending step further comprises constructing a best-fit curve from scatter point data.    
   
   
       55 . A method as in  claim 54  wherein said accumulated data is acquired by measuring each said selected conduction time and logging the values in a periodic repeating programmable basis to produce cumulative data.  
   
   
       56 . A method as in  claim 55  wherein said cardiac conduction times are related to one or more sensed parameters of interest.  
   
   
       57 . A method as in  claim 56  wherein said one or more sensed parameters are selected from the group consisting of cycle length, activity level and minute ventilation.  
   
   
       58 . A method as in  claim 55  wherein said cardiac conduction times are selected from (RA-RV), (LA-LV), (RV-LV), (RA-LA), (RA-LV) and (LV 1 -LV 2 ).  
   
   
       59 . A method as in  claim 56  wherein said cardiac conduction times are selected from (RA-RV), (LA-LV), (RV-LV), (RA-LA), (RA-LV) and (LV 1 -LV 2 ).  
   
   
       60 . A method as in  claim 57  wherein said cardiac conduction times are selected from (RA-RV), (LA-LV), (RV-LV), (RA-LA), (RA-LV) and (LV 1 -LV 2 ).  
   
   
       61 . A method as in  claim 55  further comprising the step of programming a new suggested optimum pace timing into the operation of said pacing device.  
   
   
       62 . A method as in  claim 55  further including the step of periodically updating said best-fit curve with new conduction time data to construct a new current best-fit curve.  
   
   
       63 . A method as in  claim 62  further comprising the step of programming a new suggested optimum pace timing into the operation of said pacing device.  
   
   
       64 . A method as in  claim 54  further comprising the step of trending a plurality of conduction times.  
   
   
       65 . A method as in  claim 54  wherein the programmable sampling interval is such that sampling occurs at different times in successive 24-hour periods, such that eventually sampling occurs throughout said 24-hour period.  
   
   
       66 . A method as in  claim 54  further including the step of enabling a manual trigger mode that will force trending of conduction time during a specific intervention.  
   
   
       67 . A method as in  claim 54  wherein the collection of conduction time data is triggered based on a sensed parameter value.  
   
   
       68 . A method of optimizing one or more inter-site pacing delays over a patient's full range of activity for use in operating an implantable cardiac pacing device comprising the steps of: 
 (a) measuring one or more conduction times selected from the group consisting of (RA-RV), (LA-LV), (RV-LV), (RA-LA), (RA-LV) and (LV-LV) for a plurality of beats and logging the values using a periodic repeating programmable sampling interval to produce cumulative data;    (b) constructing a best-fit curve from scatter point data of one or more selected conduction times in relation to one or more sensed parameters of interest selected from the group consisting of cycle length, activity level and minute ventilation over a desired range of patient activity levels from said cumulative data; and    (c) based on a then best-fit curve derive a suggested optimum pacing delay.    
   
   
       69 . A method as in  claim 68  further comprising the step of programming a suggested optimum delay into the operation of said pacing device based.  
   
   
       70 . A method as in  claim 68  further comprising the step of periodically updating one or more best-fit curves with new conduction time data to construct one or more new current best-fit curves and thereby deriving one or more new suggested optimum delays.  
   
   
       71 . A method as in  claim 70  further comprising the step of programming updated suggested optimum delays into the operation of said pacing device.  
   
   
       72 . A method as in  claim 68  wherein the programmable sampling interval is such that sampling occurs at different times in successive 24-hour periods, such that eventually sampling occurs throughout said 24-hour period.  
   
   
       73 . A method as in  claim 68  further including the step of enabling a manual trigger mode that will force trending of conduction time during a specific intervention.  
   
   
       74 . A method as in  claim 68  wherein the collection of conduction time data is triggered based on a sensed parameter value.  
   
   
       75 . A method of optimizing atrio-ventricular delay over a patient's full range of activity for use in operating an implantable cardiac pacing device comprising the steps of: 
 measuring atrio-ventricular conduction time for a plurality of beats and logging the values on a periodic repeating programmable basis to produce cumulative data;    constructing a best-fit curve from scatter point data of atrio-ventricular conduction time in relation to one or more other sensed parameters of interest over a desired range of patient activity levels from the said cumulative data;    based on a then best-fit curve derive a suggested optimum atrio-ventricular delay.    
   
   
       76 . A method as in  claim 75  wherein said one or more sensed parameters are selected from the group consisting of cycle length, activity level and minute ventilations.  
   
   
       77 . A method as in  claim 75  further comprising the step of programming a suggested optimum atrio-ventricular delay into the operation of said pacing device.  
   
   
       78 . A method as in  claim 75  further including the step of periodically updating said best-fit curve with new atrio-ventricular conduction time data to construct a new current best-fit curve and deriving a new suggested optimum atrio-ventricular delay.  
   
   
       79 . A method as in  claim 76  wherein said suggested optimum atrio-ventricular delay is a dynamic atrio-ventricular delay that changes as a function of one or more said sensed parameters of interest.  
   
   
       80 . A method as in  claim 77  wherein said suggested optimum atrio-ventricular delay is a dynamic atrio-ventricular delay that changes as a function of one or more said sensed parameters of interest.  
   
   
       81 . A method as in  claim 77  wherein said suggested optimum atrio-ventricular delay is a fixed atrio-ventricular delay.  
   
   
       82 . A method as in  claim 80  further comprising the step of changing the atrio-ventricular delay automatically when the best-fit curve is updated with a minimum amount of new atrio-ventricular conduction time data.  
   
   
       83 . A method as in  claim 75  wherein the measurement of said atrio-ventricular conduction time includes lengthening the then current AV delay so that intrinsic measurements can be made.  
   
   
       84 . A method as in  claim 75  wherein the data from each measurement is based on a discrete number of beats and is processed by exponential averaging and stored in incremental bins according to the value of the related parameter of interest and wherein a minimum number of beats must be averaged in a minimum number of bins to trigger best-fit curve generation including updating.  
   
   
       85 . A method as in  claim 84  wherein the parameter of interest is selected from cycle length, activity level and minute ventilation.  
   
   
       86 . A method as in  claim 84  wherein the best-fit curve is generated based on a best fit mathematical relation between atrio-ventricular conduction time and a selected parameter of interest.  
   
   
       87 . A method as in  claim 85  wherein the best-fit curve is generated based on a best fit mathematical relation between atrio-ventricular conduction time and the parameter of interest.  
   
   
       88 . A method as in  claim 58  wherein the best-fit curve is generated based on a best fit mathematical relation between atrio-ventricular conduction time and the parameter of interest.  
   
   
       89 . A method as in  claim 84  wherein the template is generated based on a programmed look-up table.  
   
   
       90 . A method as in  claim 58  wherein the template is generated based on a programmed look-up table.  
   
   
       91 . A method as in  claim 75  wherein the programmable sampling interval is such that sampling occurs at different times in successive 24-hour periods, such that eventually sampling occurs throughout said 24-hour period.  
   
   
       92 . A method as in  claim 75  further including a step of enabling a manual trigger mode that will force trending of atrio-ventricular conduction time during a specific intervention.  
   
   
       93 . A method as in  claim 92  wherein said intervention is a specific exercise test.  
   
   
       94 . A method as in  claim 75  wherein the collection AV atrio-ventricular conduction time data is triggered based on a sensed parameter value.  
   
   
       95 . A method as in  claim 75  wherein the atrio-ventricular conduction time is measured based on a selected morphological marker of ventricular depolarization and the atrio-ventricular delay is increased above the intrinsic during such measurements.  
   
   
       96 . An implantable cardiac rhythm management device programmed to operate in accordance with  claim 54.