Method and apparatus to continuously optimize the A-V delay in a dual chamber pacemaker
First Claim
1. Cardiac stimulating apparatus for use with a patient comprising, in combination:
- (a) means for sensing atrial depolarization signals;
(b) means for sensing ventricular depolarization signals;
(c) means for stimulating ventricular tissue; and
(d) microprocessor-based controller means coupled to said means for sensing ventricular depolarization signals for determining a heart rate variability index (HRVi) during a predetermined time interval, said controller means further being coupled to said means for sensing atrial depolarization signals for establishing an optimum A-V delay interval corresponding to a minimum HRVi, said controller means coupled in controlling relation to said means for stimulating ventricular tissue for causing said ventricular tissue to be stimulated in at least one ventricular chamber after expiration of said optimum A-V delay interval following the sensing of an immediately preceding atrial depolarization signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A DDD-type cardiac pacemaker having a microprocessor-based controller is programmed to automatically determine and utilize and optimize A-V delay for the patient in whom the device is implanted. The microprocessor-based controller periodically changes the A-V delay and then computes heart rate variability over an insuing predetermined period. The particular A-V delay value associated with the minimum heart rate variability index is determined to be the optimum. Heart rate variability may be determined by performing a power spectrum analysis on cyclic variations in R-R intervals, preferably using a FFT signal processing chip, or by a time domain analysis based upon the standard deviation of R-R intervals during a prescribed period of time and a calculated value of respiratory sinus arrhythmia. The apparatus is also operative to optimize the A-V delay interval following a change in the pacing mode of the DDD-type pacemaker.
211 Citations
22 Claims
-
1. Cardiac stimulating apparatus for use with a patient comprising, in combination:
-
(a) means for sensing atrial depolarization signals; (b) means for sensing ventricular depolarization signals; (c) means for stimulating ventricular tissue; and (d) microprocessor-based controller means coupled to said means for sensing ventricular depolarization signals for determining a heart rate variability index (HRVi) during a predetermined time interval, said controller means further being coupled to said means for sensing atrial depolarization signals for establishing an optimum A-V delay interval corresponding to a minimum HRVi, said controller means coupled in controlling relation to said means for stimulating ventricular tissue for causing said ventricular tissue to be stimulated in at least one ventricular chamber after expiration of said optimum A-V delay interval following the sensing of an immediately preceding atrial depolarization signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for setting the A-V delay of an implantable DDD pacemaker of the type having a means for sensing atrial events, means for sensing ventricular events, means for stimulating ventricular tissue and a programmable microprocessor-based controller coupled to said atrial and ventricular sensing means and to said means for stimulating ventricular tissue comprising the steps of:
-
(a) establishing an initial A-V delay interval between the sensing of an atrial event and an actuation of said means for stimulating ventricular tissue; (b) measuring a heart rate variability index (HRVi) of a patient in whom said pacemaker is implanted for a predetermined period of time following the establishing of each A-V delay interval and determining an average value for said period; (c) incrementing the length of said initial A-V interval by a predetermined amount during iterative cycles until a predetermined A-V interval limit is reached and for each new value thereof computing HRVi over a predetermined length of time; (d) storing said A-V delay interval and the associated HRVi following each iteration of step (c); (e) setting said A-V interval to the value associated with the minimum HRVi stored after said A-V interval limit has been reached. - View Dependent Claims (12, 13, 14, 15, 16)
-
-
17. A method of determining the optimum pacing mode for a cardiac stimulator of the type having a means for sensing atrial events, means for sensing ventricular events, means for stimulating ventricular tissue, a means for stimulating atrial tissue and a programmable microprocessor-based controller coupled to said atrial and ventricular sensing means and to said means for stimulating ventricular tissue and said means for stimulating atrial tissue comprising the steps of:
-
(a) programming the stimulator to operate in a first pacing mode; (b) thereafter establishing an initial A-V delay interval between the sensing of an atrial event and the actuation of said means for stimulating ventricular tissue; (c) measuring a heart rate variability index (HRVi) of a patient in whom said cardiac stimulator is implanted for a predetermined period of time following the establishing of each A-V delay interval and determining an average value for said period; (d) incrementing the length of said initial A-V interval by a predetermined amount during iterative cycles until a predetermined A-V interval limit is reached and for each new value thereof, computing said HRVi over a predetermined length of time; (e) storing said A-V delay interval and its associated HRVi following each iteration of step (d); (f) determining the average HRVi ; (g) programming the cardiac stimulator to operate in a second pacing mode different from said first pacing mode; (h) repeating steps b through f; (i) comparing the average HRVi computed in step f with that computed in step h; and (j) programming the cardiac stimulator to operate in the mode yielding the minimum average HRVi. - View Dependent Claims (18, 19, 20, 21, 22)
-
Specification