Method and apparatus for automatically programming CRT devices

Abstract

External or internal monitoring equipment is used to automatically determine optimal programming parameters for a CRT based on externally or internally derived measurements of cardiac performance, anisotropic myocardial deformation (AMD) or both. The ideal programming parameter, operational parameter, represents optimal interval timing between multiple electrodes within the CRT, and is generated by such a closed loop control system. The closed loop system may be semi-automatic and implement connectivity to external ultrasound equipment or externally derived measurements of transthoracic impedance. Preferably, the operational parameter is determined by a closed loop system using internally derived intracardiac and intrathoracic electrograms and impedance measurements that describe cardiac performance and electromechanical dysynchrony in real time. Such a CRT has a control system that automatically optimizes performance by a system of checks and balance.

1 . A method comprising: 
 measuring an intra-thoracic impedance between at least two spaced apart electrodes; and    stimulating one or more chambers of a patient's heart to optimize cardiac performance based at least in part on the intra-thoracic impedance.    
   
   
       2 . The method of  claim 1  further comprising stimulating the patient's heart with a plurality of different stimulation parameters and determining one or more programming parameters for an implantable medical device to optimize the cardiac performance based at least in part on the intra-thoracic impedance for each of the plurality of different stimulation parameters.  
   
   
       3 . The method of  claim 2  wherein determining one or more programming parameters for an implantable medical device comprising determining an inter-chamber delay.  
   
   
       4 . The method of  claim 2  wherein determining one or more programming parameters for an implantable medical device comprising determining an intra-chamber delay.  
   
   
       5 . The method of  claim 3  wherein determining an intra-chamber delay comprises determining an atrial-ventricular delay.  
   
   
       6 . The method of  claim 3  wherein determining an intra-chamber delay comprises determining an inter-ventricular delay.  
   
   
       7 . A method comprising: 
 measuring myocardial strain of specific regions of a patient's heart; and    stimulating one or more chambers of a patient's heart to optimize cardiac performance based at least in part on the myocardial strain.    
   
   
       8 . The method of  claim 7  further comprising stimulating the patient's heart with a plurality of different stimulation parameters and determining one or more programming parameters for an implantable medical device to optimize the cardiac performance based at least in part on the measured myocardial strain for each of the plurality of different stimulation parameters.  
   
   
       9 . The method of  claim 8  wherein determining one or more programming parameters for an implantable medical device comprising determining an inter-chamber delay.  
   
   
       10 . A method comprising: 
 measuring myocardial velocity of specific regions of a patient's heart; and    stimulating one or more chambers of a patient's heart to optimize cardiac performance based at least in part on the myocardial velocity.    
   
   
       11 . The method of  claim 10  further comprising stimulating the patient's heart with a plurality of different stimulation parameters and determining one or more programming parameters for an implantable medical device to optimize cardiac performance based at least in part on the measured myocardial velocity for each of the plurality of different stimulation parameters.  
   
   
       12 . The method of  claim 11  wherein determining one or more programming parameters for an implantable medical device comprising determining an inter-chamber delay.  
   
   
       13 . The method of  claim 10  wherein measuring myocardial velocity comprises measuring myocardial velocity using Doppler ultrasound quantification of velocity of multiple pre-selected myocardial regions during a cardiac cycle.