Pacing methods, systems and computer program products for using feedback controlled timing

Abstract

Methods, systems and computer program products for cardiac pacing are provided. For pacing using biventricular synchronization in a patient, a first stimulation signal is applied to a first region of a heart of the patient at a first time and a second stimulation signal applied to a second region of the heart of the patient at a second time to provide biventricular synchronization stimulation of the heart. Cardiac function of the patient associated with application of the first and the second stimulation signals is sensed and a timing relationship of the first stimulation signal to the second stimulation signal is adjusted based on the sensed cardiac function. Additionally, a cardiac timing interval, such as the A-V timing interval, may be adjusted by applying stimulation to a heart of the patient utilizing a cardiac timing interval, detecting a change in cardiac function by sensing cardiac function associated with application of the stimulation using the cardiac timing interval and adjusting the cardiac timing interval directly from the detected change in cardiac function.

1 . A computer program product for controlling pacing in a patient by biventricular synchronization, comprising: 
 a computer readable medium having computer readable program code embodied therein, the computer readable program code comprising:    computer readable program code configured to apply a first stimulation signal to a first region of a heart of the patient at a first time;    computer readable program code configured to apply a second stimulation signal to a second region of the heart of the patient at a second time so as to provide biventricular synchronization treatment to the heart;    computer readable program code configured to sense cardiac function associated with application of the first and the second stimulation signals; and    computer readable program code configured to adjust a timing relationship of application of the first stimulation signal with respect to application of the second stimulation signal based on the sensed cardiac function.    
   
   
       2 . The computer program product of  claim 1 , further comprising: 
 computer readable program code configured to apply stimulation to a heart of the patient utilizing an A-V timing interval;    computer readable program code configured to detect a change in cardiac function by sensing cardiac function associated with application of the stimulation using the A-V timing interval; and    computer readable program code configured to adjust the A-V timing interval based on the detected change in cardiac function.    
   
   
       3 . A method of cardiac pacing in a patient, comprising: 
 applying stimulation to a heart of the patient utilizing a cardiac timing interval;    detecting a change in cardiac function by sensing cardiac function associated with application of the stimulation using the cardiac timing interval; and    adjusting the cardiac timing interval directly from the detected change in cardiac function.    
   
   
       4 . The method of  claim 3 , wherein the cardiac timing interval comprises a pacing interval.  
   
   
       5 . The method of  claim 3 , wherein the step of applying stimulation comprises applying stimulation to the heart utilizing a single electrode.  
   
   
       6 . The method of  claim 3 , wherein the cardiac timing interval comprises a timing interval from a reference signal to a left ventricular stimulation and/or a timing interval from the reference signal to a right ventricular stimulation.  
   
   
       7 . The method of  claim 6 , wherein the cardiac timing interval is adjusted so as to adjust a timing relationship between the left ventricular stimulation and the right ventricular stimulation.  
   
   
       8 . The method of  claim 6 , wherein the cardiac timing interval is adjusted so as to adjust a timing between both the left ventricular stimulation and the right ventricular stimulation and the reference signal.  
   
   
       9 . The method of  claim 6 , wherein the reference signal comprises a spontaneous atrial signal.  
   
   
       10 . The method of  claim 6 , wherein the reference signal comprises a pacing stimulation.  
   
   
       11 . The method of  claim 3 , wherein the cardiac timing interval comprises an A-V timing interval.  
   
   
       12 . The method of  claim 11 , wherein the step of detecting a change in cardiac function comprises detecting a change in cardiac function by sensing changes in impedance and wherein the step of adjusting the A-V timing interval comprises adjusting the A-V timing interval directly from the sensed changes in impedance.  
   
   
       13 . The method of  claim 12 , wherein the step of detecting a change in cardiac function by sensing changes in impedance comprises detecting a change in cardiac function by measuring impedance utilizing a conductance catheter positioned proximate a left ventricle of the heart of the patient.  
   
   
       14 . The method of  claim 11 , wherein the step of detecting a change in cardiac function by sensing cardiac function comprises detecting a change in cardiac function by measuring changes in distance and/or the rate of change in distance between at least two locations on the heart of the patient and wherein the step of adjusting the A-V timing interval comprises the step of adjusting the A-V timing interval directly from the changes in distance and/or the rate of change in distance.  
   
   
       15 . The method of  claim 14 , wherein the step of detecting a change in cardiac function by measuring changes in distance and/or the rate of change in distance comprises detecting a change in cardiac function by measuring changes in distance and/or the rate of change in distance between at least an electrode positioned on a left ventricle and an electrode positioned within a right ventricle of the heart of the patient.  
   
   
       16 . The method of  claim 14 , wherein the step of detecting a change in cardiac function by measuring changes in distance and/or the rate of change in distance comprises detecting a change in cardiac function by measuring changes in distance and/or the rate of change in distance utilizing ultrasonic crystals.  
   
   
       17 . The method of  claim 16 , wherein the ultrasonic crystals are placed on electrodes that receive the first and the second stimulation signals.  
   
   
       18 . The method of  claim 11 , wherein the step of detecting a change in cardiac function by sensing cardiac function comprises detecting a change in cardiac function by measuring motion of a location associated with the heart of the patient and wherein the step of adjusting the A-V timing interval comprises adjusting the A-V timing interval directly from the measured motion.  
   
   
       19 . The method of  claim 18 , wherein the location associated with the heart of the patient comprises a left ventricle of the heart of the patient.  
   
   
       20 . The method of  claim 18 , wherein the step of detecting a change in cardiac function by measuring motion comprises detecting motion utilizing an accelerometer.  
   
   
       21 . The method of  claim 20 , further comprising: 
 determining a derivative of the detected motion; and    estimating cardiac function based on the determined derivative.    
   
   
       22 . The method of  claim 20 , further comprising: 
 determining an integral of the detected motion; and    estimating cardiac function based on the determined integral.    
   
   
       23 . The method of  claim 20 , further comprising estimating cardiac function based on the detected motion and wherein the step of adjusting a timing relationship comprises adjusting the A-V timing directly from the estimated cardiac function.  
   
   
       24 . The method of  claim 11 , further comprising repeating applying stimulation to a heart of the patient utilizing an A-V timing interval, detecting a change in cardiac function by sensing cardiac function associated with application of the stimulation using the A-V timing interval and adjusting the A-V timing interval directly from the detected change in cardiac function until adjusting the A-V timing interval does not improve cardiac function.  
   
   
       25 . The method of  claim 24 , further comprising: 
 determining if a predefined time interval has expired; and    carrying out the steps of applying stimulation to a heart of the patient utilizing an A-V timing interval, detecting a change in cardiac function by sensing cardiac function associated with application of the stimulation using the A-V timing interval, adjusting the A-V timing interval directly from the detected change in cardiac function and repeating if the predefined time interval has expired.    
   
   
       26 . The method of  claim 24 , further comprising: 
 determining if a change in cardiac function has occurred; and    carrying out the steps of applying stimulation to a heart of the patient utilizing an A-V timing interval, detecting a change in cardiac function by sensing cardiac function associated with application of the stimulation using the A-V timing interval, adjusting the A-V timing interval directly from the detected change in cardiac function and repeating if a change in cardiac function has occurred.    
   
   
       27 . The method of  claim 24 , further comprising: 
 receiving an external signal initiating recalibration of A-V interval timing; and    carrying out the steps of applying stimulation to a heart of the patient utilizing an A-V timing interval, detecting a change in cardiac function by sensing cardiac function associated with application of the stimulation using the A-V timing interval, adjusting the A-V timing interval directly from the detected change in cardiac function and repeating responsive to receipt of the external signal.    
   
   
       28 . The method of  claim 11 , wherein the steps of detecting a change in cardiac function by sensing cardiac function associated with application of the stimulation using the A-V timing interval, adjusting the A-V timing interval directly from the detected change in cardiac function are performed each time the stimulation is applied.  
   
   
       29 . The method of  claim 11 , wherein the steps of applying stimulation to a heart of the patient utilizing an A-V timing interval, detecting a change in cardiac function by sensing cardiac function associated with application of the stimulation using the A-V timing interval and adjusting the A-V timing interval directly from the detected change in cardiac function are carried out by an implantable pacing device.  
   
   
       30 . The method of  claim 11 , wherein the step of detecting a change in cardiac function by sensing cardiac function further comprises at least one of sensing heart rate of the patient and/or sensing timing and/or morphology of at least one intrinsic ventricular beat of the heart of the patient.  
   
   
       31 . The method of  claim 15 , wherein the step of adjusting the A-V timing interval comprises adjusting the A-V timing interval utilizing a variable adjustment interval.  
   
   
       32 . The method of  claim 25 , wherein the step of repeating is successively repeated utilizing finer timing adjustment intervals.  
   
   
       33 . The method of  claim 11 , wherein the step of adjusting the A-V timing interval comprises increasing the A-V timing interval.  
   
   
       34 . The method of  claim 11 , wherein the step of adjusting the A-V timing interval comprises decreasing the A-V timing interval.  
   
   
       35 . The method of  claim 11 , wherein the step of adjusting the A-V timing interval comprises adjusting the A-V timing interval utilizing a fixed adjustment interval.  
   
   
       36 . A system for cardiac pacing in a patient, comprising: 
 an electrode stimulation timing circuit configured to control a cardiac timing interval of application of stimulation to a heart of the patient;    a cardiac function sensing circuit configured to detect a change in cardiac function by sensing cardiac function associated with application of the stimulation; and    a feedback control circuit operatively associated with the electrode stimulation timing circuit and the cardiac function sensing circuit and configured to adjust the cardiac timing interval directly from the detected change in cardiac function.    
   
   
       37 . The system of  claim 36 , wherein the cardiac timing interval comprises a pacing interval.  
   
   
       38 . The system of  claim 36 , wherein the cardiac timing interval comprises an A-V timing interval.  
   
   
       39 . The system of  claim 36 , wherein the cardiac timing interval comprises a timing interval from a reference signal to a left ventricular stimulation and/or a timing interval from the reference signal to a right ventricular stimulation.  
   
   
       40 . A system for cardiac pacing in a patient, comprising: 
 means for applying stimulation to a heart of the patient utilizing a cardiac timing interval;    means for detecting a change in cardiac function by sensing cardiac function associated with application of the stimulation using the cardiac timing interval; and    means for adjusting the cardiac timing interval directly from the detected change in cardiac function.    
   
   
       41 . The system of  claim 40 , wherein the cardiac timing interval comprises a pacing interval.  
   
   
       42 . The system of  claim 40 , wherein the cardiac timing interval comprises an A-V timing interval.  
   
   
       43 . The system of  claim 40 , wherein the cardiac timing interval comprises a timing interval from a reference signal to a left ventricular stimulation and/or a timing interval from the reference signal to a right ventricular stimulation.  
   
   
       44 . A computer program product for controlling cardiac pacing in a patient, comprising: 
 a computer readable medium having computer readable program code embodied therein, the computer readable program code comprising:    computer readable program code configured to apply stimulation to a heart of the patient utilizing a cardiac timing interval;    computer readable program code configured to detect a change in cardiac function by sensing cardiac function associated with application of the stimulation using the cardiac timing interval; and    computer readable program code configured to adjust the A-V timing interval directly from the detected change in cardiac function.    
   
   
       45 . The computer program product of  claim 44 , wherein the cardiac timing interval comprises a pacing interval.  
   
   
       46 . The computer program product of  claim 44 , wherein the cardiac timing interval comprises an A-V timing interval.  
   
   
       47 . The computer program product of  claim 44 , wherein the cardiac timing interval comprises a timing interval from a reference signal to a left ventricular stimulation and/or a timing interval from the reference signal to a right ventricular stimulation.